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International Journal of latest Research in Engineering and Technology (IJLRET) Print Version, Volume 01, Issue 07 December 2015 Edition ISSN 2454-5031

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International Journal of latest Research in Engineering and Technology (IJLRET)

Volume 01, Issue 07 December 2015 Edition

ISSN 2454-5031

Contents The design and construction of a potable rechargeable lamp with automatic mechanical manual timer control switch………………………………………………………………………………………………………………………………………………………01

Olaitan S.K and Aladenika A.K………………………………………………………………………………………………………………..01

Generation of electricity by running on a leg-powered treadmill………………………………………………………………………….04 Manish Debnath…………………………………………………………………………………………………………………………………….04 Review of Low Temperature Air Generation from Vehicle Suspension System……………………………………………………..08 Prof. S. U. Ratnparkhi, Mr. Tejas Tharkude, Ms. Swarada Radkar, Ms. Niyati Shah, Mr. Vishal Parekar…08 A Modified Binary Search Algorithm for Carrier Acquisition in DSB-SC Communication System……………………………13 Muhammad Asif, Anam Nusrat……………………………………………………………………………………………………………..13 Medical image de-noising using Anisotropic Diffusion………………………………………………………………………………………….22 Himali R. Bonde, Prof. S. A. More………………………………………………………………………………………………………….22 Genetic potential evaluation of Binbei area in the Songliao Basin………………………………………………………………………. 29 Dai xiaojuan………………………………………………………………………………………………………………………………………….29 Effect of Biogenic Silica Soil Conditioner on Paddy Crop in India…………………………………………………………………………..33 S. T. Buddhe, M.G. Thakre, Sanyogita Verma and P.R. Chaudhari………………………………………………………..33

EFFECTS OF TERMITES ON CONSTRUCTION TIMBERS IN IBARAPA EAST LOCAL GOVERNMENT AREA OF OYO STATE IN NIGERIA…………………………………………………………………………………………………………………………………………40 Olaniyan, A, Ibikunle, O. A, Olayanju, A. B, Olagoke, B. E and Olawoore, W. A …………………………………..40 COMPLEX TRUSS ANALOGY USING PLASTIC AND ELASTIC ANALYSIS ……………………………………………………………………49 Ezeagu C.A. and Onunkwo R.C…………………………………………………………………….…………………………………..49

International Journal of Latest Research in Engineering and Technology (IJLRET)

ISSN: 2454-5031(Online)

www.ijlret.comǁ Volume 1 Issue 7ǁDecember 2015 ǁ PP 01-03

www.ijlret.com 1 | Page

THE DESIGN AND CONSTRUCTION OF A POTABLE

RECHARGEABLE LAMP WITH AUTOMATIC

MECHANICAL MANUAL TIMER CONTROL SWITCH.

Olaitan S.K and Aladenika A.K Department of Science Laboratory Technology,

Rufus Giwa Polytechnic,

Owo Ondo State, Nigeria.

ABSTRACT: A rechargeable lamp is a portable lighting device or mounted light fixture used to illuminate

broad areas. Lamps may also be used for signaling, as torches, or as general light sources outdoors. Low light

level varieties are used for decoration. The term "lamp" is also used more generically to mean a light source, or

the enclosure for a light source. The design and construction of a potable rechargeable lamp was constructed to

add more values to existent ones. The introduction of the automatic mechanical manual timer control switch

which was introduced was serve as off and on switch , to make the rechargeable lamp valuable, durable,

increase the efficiency and life span of the battery.

Keywords: automatic mechanical manual timer, rechargeable battery, LEDs.

INTRODUTION A lamp is a portable lighting device or mounted light fixture used to illuminate broad areas. Lamps

may also be used for signaling, as torches, or as general light sources outdoors. Low light level varieties are

used for decoration. The term "lamp" is also used more generically to mean a light source, or the enclosure for a

light source. Examples are glass pane enclosed streetlights, or the housing for the top lamp and lens section of a

lighthouse (Douglas, 2014). The introductions of the manual timer control switch which is introduced to serve

as off and on, to make the rechargeable valuable, durable, increase the efficiency and life span of the battery.

Lamps were used by the ancients in augury. The only known representation of an ancient Egyptian lamps

probably is not much different from those spoken of by John the Evangelist in John 18:3 from the New

Testament, where the party of men who went out of Jerusalem to apprehend Jesus in the garden of Gethsemane

is described as being provided “with lamps and torches (Farago,1996). Lamps in ancient China were made of

silk, paper, or animal skin with frames made of bamboo or wood. One of the earliest descriptions of lamp is

found in records from Khorana, which describes a "mounting lamp" made of white paper (James et al., 1982).

The simplest technology used is the candle lantern. Candles give only a faint light, and must be protected from

wind to prevent flickering or complete extinguishment. A typical candle lamp is a metal box or cylinder with

glass or mica side panels and an opening or ventilated cover on the top. A primitive form of candle lantern,

made from white horn and wood and called a lanthorn, was first made in the time of the English king Alfred the

Great (849–899) (James et al.,1982).

Decorative lamps exist in a wide range of designs. Some hang from buildings, while others are placed on or just

above the ground. Paper lamps occur in societies around the world. Modern varieties often place an electric light

in a decorative glass case. The ancient Chinese sometimes captured fireflies in transparent or semi-transparent

containers and used them as (short-term) lamps. Raise the red lamp, a Chinese film, prominently features lamps

as a motif. Lamps are used in many Chinese festivals. During the Ghost Festival, lotus shaped lamps are set

afloat in rivers and seas to symbolic guide the lost souls of forgotten ancestors to the afterlife. During the Lamp

Festival, the displaying of many lamps is still a common sight on the 15th day of the first lunar month

throughout China. In Chinese festivities, the kongming lanterns can be seen floating high into the sky during

festivities (Vishay,2008).

METHODOLOGY

All the materials are locally purchase in Owo, Ondo State Nigeria and mounted on a circuit board according

circuit diagram shows below

http://en.wikipedia.org/wiki/Portable

http://en.wikipedia.org/wiki/Portable

http://en.wikipedia.org/wiki/Street_light

http://en.wikipedia.org/wiki/Lamp_%28electrical_component%29

http://en.wikipedia.org/wiki/Lighthouse

http://en.wikipedia.org/wiki/Augury

http://en.wikipedia.org/wiki/Ancient_Egypt

http://en.wikipedia.org/wiki/John_the_Evangelist

http://en.wikipedia.org/wiki/New_Testament



http://en.wikipedia.org/wiki/Jerusalem

http://en.wikipedia.org/wiki/Jesus

http://en.wikipedia.org/wiki/Garden_of_Gethsemane

http://en.wikipedia.org/wiki/History_of_China#Ancient_China

http://en.wikipedia.org/wiki/Candle

http://en.wikipedia.org/wiki/Mica

http://en.wikipedia.org/wiki/Alfred_the_Great



http://en.wikipedia.org/wiki/Paper_lantern

http://en.wikipedia.org/wiki/China

http://en.wikipedia.org/wiki/Firefly

http://en.wikipedia.org/wiki/Motif_%28art%29

http://en.wikipedia.org/wiki/Ghost_Festival

http://en.wikipedia.org/wiki/Lantern_Festival



THE DESIGN AND CONSTRUCTION OF A POTABLE RECHARGEABLE LAMP WITH


Figure 1: circuit diagram ofrechargeable lamp. (www.homemade-circuits.com/2011/12/how-to-make-efficient-

led-emergency)

Figure 2: The modified rechargeable lamp circuit with automatic mechanical control switch.

POWER SUPPLY UNIT The power supply unit consist of a step down transformer of a value 240-9volt were connected to the four

diodes which were connected back to back and front to front to the capacitor(100nf/50volt) and the capacitor

convert the alternative current of 9voltage which is the output from the transformer to direct current. The

positive were connected to the emitter of the transistor the negative was connected to 1khom resistor both

positive and negative leg were connected battery terminal to charge the rechargeable battery.

The rectified output passes through an electrolytic capacitor to filter out the ripples. The resistor in this power

supply unit was used as a current limiter (i.e. current limiting resistor) also an indicator which is a light

emitting diode (LED) was used to indicate the presence of alternative current in the circuit.

T

http://www.homemade-circuits.com/2011/12/how-to-make-efficient-led-emergency

http://www.homemade-circuits.com/2011/12/how-to-make-efficient-led-emergency

THE DESIGN AND CONSTRUCTION OF A POTABLE RECHARGEABLE LAMP WITH


CHARGING UNIT The charging unit of this circuit includes capacitor and also the battery when the battery is in the discharge

state. It provides output voltage of 9volt, this output voltage drives the transistor and LEDs

AUTOMATIC MECHANICAL CONTROL TIMER

The automatic mechanical control timer isconnected in between collector terminal of TIP 122 transistor and the

LED terminal.

LIGHT EMITTING DIODE CIRCUIT The circuit consist of 24 light emitting diode which were connected in parallel form to each other on a

veroboard while all the positive terminal where connected to positive terminal of the timer and all negative

terminals were connected to 1kohms resistor.

RESULTS AND DISCUSSION This rechargeable lampworks efficiently and the introductions of the automatic mechanical manual timer make

this rechargeable more durable and expand the lifespan of the battery compare when compare with rechargeable

lamp show in figure 1

CONCLUSION With introduction of automatic mechanical manual timer introduce shows that it prolong and extended the

life span of both the rechargeable battery and LEDs.

REFRENCES

[1]. Douglas, W.H. (2013) Department of Electrical and Computer Engineering, University of Waterloo.

Retrieved 2014-09-11

[2]. Farrago, P.S. (2006) An Introduction to Linear Network Analysis, The English University Press Ltd

pp 18-21

[3]. James, H .H. Paul, N.L. (1982) Essentials of Electrical Circuit, Reston publishing Company pp 96-97

[4]. Vishay, B.S.(2008) Basic of Linear Fixed Resistor Application page 34-37

[5]. www.homemade-circuits.com/2011/12/how-to-make-efficient-led- emergency

http://www.homemade-circuits.com/2011/12/how-to-make-efficient-led-%09emergency





Generation of electricity by running on a leg-powered treadmill

Manish Debnath (B-tech in Electrical Engineering, NIT, Agartala, India)

ABSTRACT:In today’s world global warming & other related environmental issues becomes an important

matter of concern in the angle of environmental pollution. To tackle this problem we have to decrease our

dependence on fossil fuel especially for generation of electricity and increase the use of green-energy or

environment friendly method of electricity generation. This paper will discuss about a treadmill which can

generate electricity when someone running on its track. Treadmill is generally used for walking or running while

staying in the same place. If someone runs on the track of this machine for one hour then it will generate certain

amount of electric energy which will be enough to lighting a LED bulb up to 10 to 12 hours.

KEYWORDS– DC generator, Diode, Inverter, LED bulb, Treadmill.

I. INTRODUCTION A treadmill is a device generally used for walking orrunning while staying in the same place.

Treadmillswere introduced before the development of poweredmachines, to harness the power of animals or

humansto do work, often a type of mill that was operated by aperson or animal treading steps of a tread-wheel

togrind grain.More recently, treadmills are not used to harness power, but used as an exercisemachines for

running or walking while staying in one place. Rather than the userpowering the mill, the machine provides a

moving platform with a wideconveyor belt (track), driven by an electric motor. The belt moves to the roller,

requiring the user to walk or run at a speed matching that of thebelt. The rate at which the belt moves is the rate

of walking or running.Thus, the speed of running may be controlled and measured. The moreexpensive,

heavydutyversions are motor-driven(usually driven by an electricmotor). The simpler, lighter, and less

expensive versions passively resist themotion, moving only when walkers push the belt with their feet. The

latter types are known as manual treadmills. The picture of a normal treadmill is given below.

Fig.1 A man running on atreadmill

Here this paper will explain about a manual (leg-powered) treadmill which canmove only when walker

push the belt with his feet. But the addition is that there is a certain number of small DC generators, whose

moving parts are mechanically coupledor connected with the moving parts of the machine (rollers) which moves

when belt of the treadmill is moving. When the rotor (moving part) of the DC generator starts moving or

rotating it will produces emf across its output terminals. This generated emf can be used for charging of Battery

or other purposes.

II. WORKING PRINCIPLE All we know about bicycle generator, where a small dc generator is attached to one of the wheel

(generally back wheel) of the bicycle. When the bicycle is running, the rotor of the generator which is attached

to the wheel of the cycle, also rotates and due to this an emfis generated across the output terminals of the

generator. This emf is then generally used for lighting the head-light of the bicycle. The diagram of a bicycle

generator is shown below.



Fig.2 Diagram of a bicycle generator (12V, 6W)

The bicycle generator is relatively small and a small torque is required to make rotation of its rotor. Here, in the

treadmill, instead of using one single large generator we use a number of small generators (bicycle

generators),electricallyconnected in parallel and mechanically coupled with the rollers of the treadmill.

III. MECHANICAL ARRANGEMENT OF THE TREADMILL

Fig.3 Basic diagram of mechanical arrangement of the treadmill

The full mechanical arrangement of the treadmill is shown in the Fig.3. In a treadmill the track which is

generally a belt, is moving on some cylindrical shape of movable parts(or rollers) and those rollers are

surrounded by the belt in both upper and lower sides. The each join side (left and right) of the roller is

mechanically coupled with the rotor of a small DC generator in such a way that when the roller starts rotating

the rotor of the DC generator also starts to rotate.

IV. ELECTRICAL CONNECTION OF THE DC GENERATORS IN THE TREADMILL

Fig.4 Electrical connection of the DC generators in the treadmill

The electrical connection of the treadmill is shown in the Fig.4. Electrically these generators are

connected in parallel with each other but here one thing is that the rotor of each DC generator is rotating exactly

in opposite direction with respect to the other DC generator which is connected in opposite side of the roller. For



example in Fig.4 the DC generators 1, 2, 3……etc. are rotating in opposite direction with respect to the

direction of the rotation of DC generators 1’, 2’, 3’…...etc. So, the emfs generated by them is also in 1800 out of

phase with respect to the other generator, situated in opposite side of the roller. To eliminate this problem we

have to connect 1, 2, 3…... etc. in parallel with the opposite terminals of the parallel connection of 1’, 2’,

3’…..etc. Moreover, we have to connect a diode with the positive terminals of each DC generators. This will

prevent them to work as a motor as they are mainly connected to the battery and their main work is to charge the

battery not to take energy from it. If for any reason the belt of the treadmill is running in opposite direction then

these diodes will prevent the current to circulate in opposite direction. There is also a capacitor connected across

the output terminals (shown in Fig.4) to prevent the fluctuations of the DC output voltage and keep it steady-

state or at a constant value.

V. CALCULATION

Fig.5 Direction of the forces acting on the treadmill

Here in the above figure (Fig.5),we saw that the force (Ftotal) is applied on the track (or belt) of treadmill by the

runner, can be divided into two components, one is vertical component (Fv) and another is the horizontal

component (Fh).

Only the horizontal component of the applied force(Fh) is responsible for moving the treadmill’s belt.

Now, the average speed of jogging for a normal man is 10 km/h. So, if someone runs with that speed then the

belt of the treadmill also runs with that speed. The dimension of a normal treadmill is shown as follows.

Fig.6 Dimension of a the treadmill

From the above diagram it is shown that the length of the belt is = (2 * 2.5 m) = 5 m (As the belt is surrounded

the rollers in both upper and lower sides). So, for one full rotation of the belt a man has to run 5m. If a man

running at a speed 10 km/h then in one hour the belt rotates = (10 * 103) / 5 =2000 times.

So, the speed of the belt rotation is 2000 r.p.h. (revolution per hour) or, (2000/60) = 33r.p.m. (revolution per

minute).

Here, the diameter of each roller is = 10 cm.

So, for each rotation of the belt one roller completes = (5 * 102) / ( * 10) = 16 full rotation. Here, the DC

generator’s rotors are coupled with the rollers. So, each generator completes 16 full rotation with one full

rotation of the belt. So, the speed of the each DC generator = (16 * 33) r.p.m. = 528 r.p.m.



This speed is enough to generate 6Watt electric power for each DC generator at 12V (output voltage).

Here, in the above arrangement of the treadmill we assume ten rollers which are surrounded by the belt.

With each roller two DC generators are mechanically connected or coupled. So, the total number of DC

generators is = (2 * 10) = 20.

Thus, the total power generating capacity of this system is = (20 * 6) = 120Watt.If one man run on this

treadmill (with average speed of 10 km/h) for one hour then the total electrical energy produced by this system

is = (120 * 1) = 120 Watt-hour.

Now, this energy can be stored in rechargeable DC batteries. Once the batteries are charged then we can use this

energy for lighting or other purposes. The efficiency of the whole system is vary from 80% to 90%. Let, we see

some of its applications.

Suppose we have a 10 Watt LED bulb, then we can lighting this bulb by directly connecting it with battery (or

with chopper circuit if needed to adjust the DC voltage at rated value) for (120 / 10) * 0.85 = 10.2 hours (taking

efficiency 85%).

We can also lighting a 40 Watt tube light (with suitable inverter circuit) for 3 to 4 hours. In one of my previous

paper[1], I discussed about a special type of inverter circuit by which we can directly lighting 40 Watt tube-light

without any choke and starter arrangement. Here we can use this inverter circuit for lighting tube-light.

VI. BLOCK DIAGRAM The complete block diagram of working of this treadmill is shown below.

Fig.7 Block diagram of working of the treadmill

VII. CONCLUSION So, here we saw that if someone runs on the treadmill for one hour then it can generate enough electrical energy

by which we can lighting 10 Watt LED bulb for at least 10 to 12 hours. In this case, we store the generated

energy in DC battery stack (array of parallel connection of DC batteries). This is one of the eco-friendly method

of generating electricity. This method is very suitable for the remote areas where the electricity is beyond the

reach of common people.This method can also be usable as a buck-up in load-shedding time.Here the running

cost is almost zero and any special maintenance is not required. This treadmill can be easily operated by anyone

(even a 10 years old children can run on it easily) as the connected DC generators are small and they require

very small torque. The only drawback of this system is that the initial cost of installation is comparatively high.

If every house install at least one treadmill of this type and lighting at least one LED bulb by this method then

we can reduce a significant portion of our consumption of fossil fuel which is spent for generating electricity.

REFERRENCES

Journal Paper:

[1] Manish Debnath,"Starting of fluorescent tube light by using inverter circuit instead of choke and starter

arrangement" Vol. 5 - Issue 11 (November - 2015), pp.57-61, International Journal of Engineering Research

and Applications (IJERA) , ISSN: 2248-9622 , www.ijera.com

Website: [2] https://en.wikipedia.org/wiki/Treadmill

Author’s Biography:

Manish Debnath, received B-tech degree in Electrical Engineering from NIT, Agartala in the

year 2014 (Enrollment no. 10UEE035). His research interest includes Power System, Power

electronics and Control System.





Review of Low Temperature Air Generation from Vehicle

Suspension System

Prof. S. U. Ratnparkhi

1, Mr. Tejas Tharkude

2, Ms. Swarada Radkar

3,

Ms. Niyati Shah4, Mr. Vishal Parekar

5

1(Mechanical Department, RMDSSOE/ Savitribai Phule PuneUniversity, India)





ABSTRACT : Nowadays we require fuel efficient car which is possible only when load on the system is

less. Hence to reduce the load on the system we have to reduce the load on the engine using the kinetic energy

generated in suspension system. Current air conditioning systems can reduce the fuel economy of high fuel

economy vehicles. With the help of the piston-cylinder arrangement it is possible to convert the compression

and expansion in suspension to reciprocating motion which will compress air at high pressure. The pneumatic

single acting cylinder is used for this project to compress the air. The output air from the pneumatic cylinder is

collected through temperature sensors and this compressed air is stored inside the storage tank. After this

research we concluded in car there is a lot of fuel burnt only for working of A.C. while driving the car. By using

this compressed air we can run the air conditioning system in the car and save the fuel. KEYWORDS–Suspension, Air-conditioning, Compressed air, fuel efficient system

1. INTRODUCTION Pneumatic systems are “fluid power control” which convert, transmit, distribute or control power through

pressurized liquid or gas. Gas is compressed above atmospheric pressure to impart the energy to the molecules

of the gas. Mostly working fluid is air due to its abundance and extremely low cost (almost negligible).Design is

simple as minimum hardware is used and compact as well as durable which makes the system suitable for

various applications like robotics, aerospace, CNC machine, food products, bomb development unit, fabrication

process of plastic .Three main parts of air conditioning system are compressor, condenser and evaporator. The

cooling system has to keep the engine safe from overheating and also to keep the engine at constant temperature.

The principle according to which the air conditioning system works is that first the compressed air passes

through heat exchanger and to the air conditioning system .The single acting cylinder is connected to suspension

system and compressed air is stored in storage tank which then passes through the heat exchanger and then the

car air conditioning system is run .This allows considerable reduction in dependence on exhaust system to

increase the efficiency of car. Our project mainly focuses on increasing efficiency of car by using available

improvement that can be made within available space and system.

2. PROBLEM STATEMENT When the suspension system of a vehicle comes into work some kinetic energy is generated. This

kinetic energy is normally wasted as there is no system which can make use of this energy. In this project we try

to convert this kinetic energy into compressed air and further try to work air conditioning system of car on this

air.

3. FINDINGS In this system we will use sensors and pressure gauge which will be an effective way to decide accuracy

and effectiveness of the system. The results will be based on the readings of the system and if the system fails to

give expected results it can be modified by changing length of spring and capacity of other components.

4. LITERATURE REVIEW “Regenerative Suspension System”, Abhijit Lendhe, Nikhil Mangvade, Prasad Naik, Pratik Jadhav,

International Journal of Recent Research in Interdisciplinary Sciences (IJRRIS) Vol. 2, Issue 2, pp;(30-33),

Month: April 2015 - June 2015. The aim of this paper is to save the waste energy which can be compressed by

Review of Low Temperature Air Generation from Vehicle Suspension System


using single acting cylinder by proper arrangement and the compressed air production using vehicle suspension

is given to the air conditioning system. This paper has explained the different components and there working to

obtain regenerative suspension system which can save fuel. The design of the system was critical part. The

paper has paid little attention to energy loss of vehicle suspension. However energy dissipated by the shock

absorber of vehicle suspension is considered only 10-20% the fuel energy is used for vehicle mobility. [1] “The Regenerative Energy Suspension System”, Gaurang Tiwari, Dr. R.K. Saxena , International Journal of

Scientific & Engineering Research, Volume 6, Issue 4, April-2015 1249. The paper revolves around the energy

dissipated by the vehicle suspensions and factors affecting the energy harvested from vehicle suspension. The

main idea proposed in this paper is that system depends on recovering this dissipated power by suspension and

converts it into regulated power using the applications of power electronics and then uses it in battery charging

or feeding some vehicle electric loads directly. The operating principle is derived from the Lenz law that states

the change in flux in a coil produces an EMF. The paper has also discussed assembly of the suspension system.

The challenges for this system are deterioration of magnetic strength, complexity in circuit and irregularities in

the voltage profile.[2] “Air Conditioning System Using Vehicle Suspension System”, Borse S.H., Satpute A.G., Mude J.M., Pokale

R.S., Prof. Wabale A. D., Prof. Bhane A.B, International Journal of Recent Development in Engineering and

Technology, (ISSN 2347-6435(Online) Volume 4, Issue 4, April 2015). The paper mainly discusses that in

conventional vehicles there is wastage of energy in vehicle suspension that is kinetic energy. This kinetic energy

is result of the movements of the suspension of the vehicle wheels. Also in vehicle the AC is essential parameter

for human comfort. But for running AC it can create large load on vehicle, which can cause engine power to

distribute and efficiency of vehicle to decrease. The AC effect can be produced by linear motion of suspension

system. To overcome the power loss on compressor, the air by using piston-cylinder arrangement, by using this

compressed air we can run AC system in the car and save fuel. This paper was very much useful for Indian

conditions because of geographical sites. Taking into consideration other manmade sites like road it is well

known fact that we have one of the best as well as worst road conditions available. [3]

“Development of Mechanism For Recovery Of Energy Of Suspension System,” Mr. Swapnil Kamthe, Mr.

Rahul Kadam, Mr. Aniket Dhore, Mr. Shivkumar Falmari, Prof. Subhash Ghadve, Prof. Mukesh Chaudhari,

IJPRET, 2014; Volume 2 (9): 169-178. This paper is divided in two systems. First part is about the Air-

conditioning working and second is Electricity generation. The regenerative system can significantly impact fuel

economy and hybrid electric vehicles (HEV) and reduce electric vehicle (EV) range. The paper presents an idea

about fuel burned for working of A.C. while driving the car and it will lead to inefficiency. The Catia model was

helpful to understand the location of the components. The paper also presented the modifications in model to

generate electricity by gear-train arrangements. [4]

5. OBJECTIVE

1. To recover the waste energy of suspension system. 2. To save fuel which is, burnt for working of A.C.

3. To run A.C. on waste energy of suspension system. 4. To increase the mileage of vehicle.

5. To use the linear motion of suspension system for electricity generation.

6. VEHICLE SUSPENSION AIR CONDITIONING SYSTEM The construction of Vehicle suspension Air Conditioning system is very simple & compact. Basically it is

assembly of Base frame Wheel, Piston-Cylinder, and Air reservoir. The complete diagram of the compressed air

production using vehicle suspension is given below. The pushing power is converted into compressed air energy

by proper driving arrangement. The pneumatic single acting Cylinder is used for this project. The spring

arrangement is fixed at the outside of the pneumatic cylinder. The spring is used to return the inclined L-angle

window in same position by releasing the load. The temperature and pressure of the output air is digitally

displayed by the temperature sensors.



Fig.1 components used in vehicle suspension system

7. COMPONENTS

Table 1: List of the components used

SR. NO. NAME QUANTITY

1 SINGLE ACTING CYLINDER 1

2 SPRING 2

3 NON RETURN VALVE 1

4 AIR TANK 1

5 HEAT EXCHANGER 1

6 THERMO-COUPLES 2

7 PRESSURE GAUGE 1

8 NOZZLE APROX.6

7.1 SPRING

Spring is elastic object used to store mechanical energy .The system will have two helical compression

springs. We are using spring to store kinetic energy, which is not used by existing suspension system. We are

using steel as material for spring. In this system we are using helical compression system which is generally

used to store energy due to resilience and subsequently release it. Force applied by helical compression spring

is directly proportional to its length.



7.2 VEHICLE BASE Base frame is made of fabrication angle. Use of base frame is to provide support and stability to all

system components. Piston-supporter and springs are mounted on the base. The valve and motor are located on

joints of frame. Another advantage of this frame is that it provides vibration isolation caused by piston-

cylinder moment.

7.3 CYLINDER The cylinder contains barrel, it shut from every end with the cinder bottom and cylinder head where

piston is connected to piston road that moves back and forth .The cylinders are used to compress the fluid. The

system will have single acting cylinder which allows feed in only one direction and return stroke provided due

the compression spring. The amount of the force produced by cylinder is depends on the air pressure supplied

to cylinder and surface are of piston. In this system the function of cylinder is based on movement of wheel

which allows piston arrangement to drive back in other direction.

7.4 NON-RETURN VALVE The basic function of this valve is to allow fluid to flow in only one direction. It is also known as check

valve or one way valve. These are two port valve means they have two opening one from which fluid enters and

other to leave the fluid. Non return valves works automatically. Mostly NVR are plastic or metallic externally.

The important aspect of check valve is it operates on minimum upstream pressure.

7.5 AIR TANK

Air tank is a closed container designed to hold fluids at pressure other than atmospheric pressure. Air

receiver is used to provide compressed air to tank. They are dangerous to handle hence regulated time to time.

The system will have the cylinder made up of mild steel and it will have two holes which may be used to pass

input and output air. The air tank is used for following purposes

1. Equalization of pressure difference from start stop and modulating sequence of the compressor 2. Storage of air volume based on consumption and demand as requirements. 3. Collecting condensed water in the air after the compression 4. Additional storage capacity made to compensate for surges in compressed usage. 5. Extra storage capacity alone outweighs the additional cost of this component.

7.6 HEAT EXCHANGER

Heat exchanger is device which provides the heat transfer from one medium to other. These two fluids

are generally separated by the solid boundaries to prevent direct contact between them or mixing between them.

They are used in many systems like refrigeration, air conditioning, power plants etc. We are using heat

exchanger for maximum efficiency and some advantages mentioned below

1. Recovery of waste heat 2. For condensation 3. Inter Cooler and after cooler

We choose shell and tube type of heat exchanger because of its high rate of transfer, compact size, and use of gases fluid is possible and large range of temperature difference.

7.7 THERMOCOUPLES

Thermocouples are created by two different metals joining at two different points known as junctions. If

one end of this junction is connected to known temperature or reference temperature other to whose temperature

is to be found, the output will be displayed directly on digital (LED) screen. The system will have two

thermocouples. On will be placed before and another will be placed after the heat exchanger. This will provide

the temperature difference of fluid and then fluid can supply to air conditioning system.

7.8 PRESSURE GAUGE The pressure gauge is device which shows the pressure of fluid under pressure. The pressure gauge is

used to indicate the pressure on air tank containing the compressed air by single stroke cylinder. This will

identify the excess of pressure and avoid accidents.



8. ADVANTAGES AND DISADVANTAGES

8.1 ADVANTAGES 1. Pollution free system. 2. It is cheap and its maintenance is low. 3. External power supply is not required. 4. Immediate results are obtained.

8.2 DISADVANTAGES 1. There might be some leakage problems. 2. Thermal stresses might affect the system.

9. CONCLUDING REMARK

This project has been designed with a vision of saving energy to its maximum level and develops an

economical and helpful system. Literature review depicts that Air Conditioning system can be run on kinetic

energy generated by suspension system. System uses the linear motion of suspension system for electricity

generation. We can recover the waste energy of suspension system by using pneumatic cylinders and display it

using temperature sensors and pressure gauge for the safety purposes which were not used earlier.

10. RECOMMENDATION Following are the suggestions given while working on this system

1. Welding and other operation can cause the leakage. 2. It is possible to generate electricity for small electric components by adding simple gear mechanisms. 3. For better performance it is recommended to use liquid nitrogen as coolant in heat exchanger. 4. We can use screw compressor instead of cylinder and large storage tank for better efficiency.

11. SCOPE: Conventionally, the vibration energy of vehicle suspension is dissipated as heat by shock absorber, which

wastes a considerable number of resources. Regenerative suspensions bring hope for recycling the wasted

energy. Systems require further research to develop a better system that will capture more energy. In future,

designers and engineers will perfectly design the regenerative suspension systems, so these systems will become

more and more common. All vehicles in motion can benefit from these systems by recapturing energy that

would have been lost during compression and expansion of suspension.

REFERENCES

Journal Papers:

[1]. Abhijit Lendhe, Nikhil Mangvade, Prasad Naik, Pratik Jadhav,“Regenerative Suspension System”,

International Journal of Recent Research in Interdisciplinary Sciences (IJRRIS) Vol. 2, Issue 2, pp: (30-33),

Month: April 2015 - June 2015.

[2]. Gaurang Tiwari, Dr. R.K. Saxena , “The Regenerative Energy Suspension System”, International Journal of

Scientific & Engineering Research, Volume 6, Issue 4, April-2015 1249.

[3]. Borse S.H., Satpute A.G., Mude J.M., Pokale R.S., Prof. Wabale A. D., Prof. Bhane A.B, “Air Conditioning

System Using Vehicle Suspension System”, International Journal of Recent Development in Engineering

and Technology, (ISSN 2347-6435(Online) Volume 4, Issue 4, April 2015).

[4]. Mr.Swapnil Kamthe, Mr.Rahul Kadam, Mr. Aniket Dhore, Mr. Shivkumar Falmari, Prof. Subhash Ghadve,

Prof .Mukesh Chaudhari,“Development of Mechanism For Recovery Of Energy Of Suspension System”,

IJPRET, 2014; Volume 2 (9): 169-178.





A Modified Binary Search Algorithm for Carrier Acquisition in

DSB-SC Communication System

Muhammad Asif

1, Anam Nusrat

2

1. School of Electronics and Information

2. Information Management and Information System

Northwestern Polytechnical University, Xi’an, China

Arslan Akbar School of Computer and Communication

University of Science and Technology Beijing,

Beijing, China

Abstract— In all DSB-SC (double side band- suppressed carrier) communication systems, acquisition of

carrier is a big challenge at the receiver. For DSB-SC modulation, the carrier is not transmitted because it

consumes a lot of power but the information is carried only by the side band. A novel algorithm for carrier

acquisition is introduced which is a modified version of Binary search Algorithm. This modified algorithm is a

hybrid of Binary search tree and Modified search tree. The proposed algorithm proves more helpful for carrier

acquisition process as it is more accurate, low cost and less time consuming. Also, the computational complexity

is very low, instead of 80-82, needs only 13-14 multiplication for carrier acquisition.

Keywords- carrier acquisition, binary search, modified binary search, primary roots, modulated signal

I. INTRODUCTION In this modern era of fast grooming communication century, almost all types of DSB-SC based communication

systems are facing the problem of acquiring the fast and efficient carrier at the receiver side. During

transmission, a carrier consumes a lot of power. Since, only the side bands contain the information about the

message, carrier is suppressed. This results in a DSB-SC wave. Basically carrier acquisition or carrier recovery

is the process of generating the carrier signal from local oscillator of receiver on the basis of frequency and

phase difference of received signal‟s carrier wave. The method used to recover message signals from DSB-SC

waveforms is known as coherent or synchronous detection (or demodulation). Carrier acquisition involves the

acquisition of both frequency and phase [3]. In practical systems, frequency acquisition is performed first,

leaving a signal constellation which is not rotating (or that rotates at a rate which is slow compared to the

signaling rate) but has a constant phase offset that needs to be corrected by the phase synchronizer [3]. The

phase synchronization problem is invariably divided into an acquisition and a tracking part. In many practical

systems, tracking is done simply and efficiently in a decision-directed (DD) mode [1], [2], and it is the

acquisition problem that is more problematic, especially in applications where no preamble is allowed.

Binary search algorithm can also be used to acquire the carrier in DSB-SC. A binary search divides a range of

values into halves, and continues to narrow down the field of search until the unknown value is found. Binary

search can be viewed as a simple guessing game in which one is given an ordered list and asked to determine an

unknown target value by making queries of the form “Is the target value greater than x?”

Binary trees are a well-known data structure with expected access time O (log2n), where n is the number of

nodes elements) stored in the tree. In an ordinary binary tree a decision on how to proceed down the tree is made

based on a comparison between the key in the current node and the key being sought.

Efficient multiplier less realization of no recursive digital filters with constant fixed point coefficients has been

an area of pervasive research interest due to its widespread applications in digital signal processing, control,

computer graphics and telecommunications [6-9,10-12].Many algorithms-including the convolution of complex

signals, autocorrelation, cross-correlation, as well as computation of the Discrete Fourier Transform (DFT)

using Fast Fourier Transform (FFT) techniques are complex multiplication bound. The idea of transform-

domain signal processing proved to be very efficient especially in adaptive filtering [5].

The paper is outlined as follows. In section II we have presented the hybrid technique of rapid acquisition of

carrier through hybrid binary tree approach. Section III represents the pseudo code. Section IV compares the

results of performance analysis of Hybrid binary technique with other commonly used carrier acquisition

techniques. Finally in section V we present the main conclusions of the work.

A Modified Binary Search Algorithm for Carrier Acquisition in DSB-SC Communication System


II. CARRIER ACQUISITION

The method of carrier acquisition which we have used in this paper is a modified form of binary search

algorithm. This modified search algorithm is a hybrid of two search algorithms which are:

Binary search tree.

Modified search tree.

Firstly the modulated signal is received by the receiver where it is analyzed to acquire carrier. The receiver

consists of two sections. One section uses the binary search tree process while the other section uses the

modified search tree. Firstly binary search tree is used for carrier acquisition method and secondly the modified

search tree is used. The overall tree diagram is a real-time tree diagram and it is formed during the process of

carrier acquisition.

This hybrid tree structure proves more helpful for carrier acquisition process as it is more accurate, low cost,

less complex and less time consuming.

The flow diagram of the receiver is shown below.

Receiver

Figure 1. Flow Diagram

Both the sections are discussed below in detail. The first step involves the binary search tree method which is

shown in Figure 2.

A. Binary search tree:

This search algorithm involves three steps for the carrier acquisition process. The process starts from the main

root or the primary root. The main root is further divided into two sub roots called the secondary roots which are

further divided into more sub roots known as tertiary roots. Each root or sub root consists of two nodes from

which a root is linked.

One node is having a high frequency and the second one is having a low frequency. In primary roots there is just

a single pair of two nodes. In the secondary roots there are two pairs of nodes while in the tertiary roots there are

four such pairs. The pair which is to be selected is decided by the correlation method. Thus during the process of

carrier acquisition only specific roots are selected that efficiently reduces the number of multiplications.

Primary roots

Secondary roots

Tertiary roots

Primary roots

Secondary roots

Binary search tree

Modified search tree

Received Modulated signal



Figure 2. Binary Tree diagram

This algorithm works on the principle of basic vector multiplication. Maximum amplitude is obtained when the

modulated signal is multiplied with that node whose frequency value closely matches with the modulated signal

carrier frequency. Thus this algorithm intelligently detects that node (high frequency or low frequency node)

near which the carrier frequency lies. The process starts from the primary roots. The nodes are multiplied with

the modulated signal and the node giving maximum amplitude is marked as the primary node. The primary node

is then multiplied with the received modulated signal. Again a maximum value is obtained at the node which is

closest to the modulated carrier frequency. Thus that node is selected as the secondary node. Similarly the

process is repeated thus giving the tertiary node. The selected node defines a new search area. Three steps are

involved therefore to reduce search area nearly up to 82-87% with just six multiplications.

To further explain our search algorithm we take an example where we obtained a modulated signal of

unknown carrier frequency within the range of 900-980Hz.

1) Process of binary search tree: Let say the received modulated signal has a carrier frequency of 906Hz. In the primary roots of binary search

tree the node „925‟ in the primary roots would be selected as it is nearest to the modulated signal carrier frequency. Similarly, the node „912‟ would be selected in the secondary roots and node „905‟ in the tertiary roots.

Figure 3. Binary search tree formation

a) Matlab results for binary search tree:

In the binary search tree includes the multiplication of the nodes having carrier frequencies „925Hz‟ and

„975Hz‟ with the modulated signal. For this purpose carriers having the frequencies equal to node frequency are

generated and multiplied with the modulated signal. Maximum amplitude is obtained at the node which is

closest to the modulated carrier frequency. In this case the node selected would be „925‟.



Figure 4. Primary roots(Binary Search Tree)

After detection through primary roots the signal moves on to secondary roots. There further two carrier signals having frequency equal to that of selected nodes are generated and multiplied with the modulated signal. Thus, the node „912‟ is selected in this step as it is nearest to the received modulated signal carrier frequency. Figure 5 shows the detection of maximum amplitude at node with „912Hz‟ carrier frequency.

Figure 5. Secondary roots(Binary Search Tree)

On the third step the signal arrives at tertiary roots where further two nodes are selected for the acquisition

process. These nodes are multiplied with the modulated signal and the maximum amplitude is observed. The

node giving maximum amplitude is marked as the tertiary node. Figure 6 Shows that the maximum amplitude is

detected at node with carrier frequency „905Hz‟.

Figure 6. Tetiary roots(Binary Search Tree)



Two multiplications are involved in each branch of binary search tree. The overall process of binary search tree involved six multiplications.

The second step involves the modified search tree method which is shown in Figure 7.

B. Modified search tree:

Figure 7. Modified Tree diagram

In the modified search algorithm an intelligent approach is used to acquire carrier. This algorithm is a hybrid of „LOOP‟ structures. Figure 7 is a model of node „905‟. Unlike binary tree structure this modified tree structure consists of only two roots. The primary roots and the secondary roots. Here the primary roots consist of four nodes instead of two showing two high frequency nodes and two low frequency nodes. The secondary roots consist of three nodes. One node represents high frequency, the other representing an intermediate frequency and the third one representing low frequency. In this modified algorithm each node is further selected by using the same approach as mentioned in Binary tree search thus reducing the search area further to 95-96% performing four multiplications at the primary roots and finally this novel algorithm detects the carrier frequency accurately by performing three or four multiplications further at the tertiary roots. Modified search algorithm thus performs a total of just 7-8 multiplications.

1) Process of modified search tree: After completing the process through the binary search tree, the signal moves to the modified search tree. The

primary root of the modified search tree involves four multiplications resulting in more efficient reduction of search area.

To explain this tree we continue our example. From the binary search tree our detected node was „905‟. Our

received modulated carrier frequency is 906Hz. Now we will see how this efficient algorithm detects the

received carrier signal correctly.

Figure 8. Modified search tree formation



At the primary roots four nodes are selected for the carrier acquisition process. These nodes are multiplied with the modulated signal and the node giving maximum amplitude is marked as the primary node. The node selected for the given example is „907‟. On the secondary roots three nodes are selected further and are multiplied with the modulated signal. This step is the final step of the whole algorithm thus detecting the node with accurate carrier frequency of modulated signal. As a result of the multiplications performed by the tertiary roots the node with carrier frequency „906Hz‟ is selected as the carrier frequency.

a) Matlab results for modified search tree: The selection of the starting node depends upon the marked tertiary node obtained from the binary tree

algorithm. In this case the node selected for the modified algorithm to start with is „905‟ as shown in Figure 8. In the primary roots of modified search tree four nodes are primarily selected and are multiplied with the

modulated signal. Here the mat lab result shows two amplitudes. This result actually shows that our search area

has been reduced to such an extent that more values for carrier frequency are arising but the correct carrier

frequency is still detected by the maximum amplitude as we can see from the Figure 9. Hence the node selected

at this step is „907‟.

Figure 9. Primary roots(Modified Search Tree)

After this stage the search area is reduced to 96%.Node with the maximum amplitude is selected. After

detection through the primary roots the signal passes to the final stage i.e. secondary roots.

In secondary roots of modified search tree three multiplications are involved to detect the modulated

carrier frequency accurately. Figure 10 shows that a single peak is obtained at the carrier frequency 906Hz. Thus

at this final step the carrier frequency of the modulated signal is detected accurately.

Figure 10. Secondary roots(Modified Search Tree)



III. PSEUDO CODE

Receiver while (! End data ()) {

Modulated signal received

Step 1

for (i->two-mid-valued-frequencies) Generate carriers on these frequencies

Correlating input signal

Plot vector

}

Save index of max(vector)

Index=k

{

for (i->two-frequencies-equally-spaced-from-k)

repeat Step 1

}

Index=k1

{

for (i->two-frequencies-equally-spaced-from-k1)

repeat Step 1

}

Index=k2

{

Step 2

for (i->three-frequencies-equally-spaced-from-k2)

perform three multiplications

save amplitudes in the vector

Plot vector

}

Index=k3

{

for (i->three-frequencies-equally-spaced-from-k3)

repeat Step 2

}

Plot vector

Note index with maximum amplitude

Index->carrier frequency

Carrier acquired

IV. RESULTS AND COMPARISON

Future of fast communication systems demands efficient techniques which employs least complexity with better results. In this section we compare the technique for carrier acquisition mentioned above with a number of other techniques to prove the efficiency, reliability and performance of this technique to the readers. The purpose of this paper is to introduce a new algorithm with least number of computations and better results.

The digital modulation/Demodulation techniques enable the efficient spectrum usage by dividing the bandwidth

into transmission channels. Different coherent detection methods are used for the carrier acquisition depending

upon the different modulation techniques.

In fast fading environments differential detection [13] and frequency discriminator detection [14]-[16] are

considered an effective technique for obtaining reliable transmission performance. But on the other hand

differential detection offers a delay of 10-150 ps in the intermediate frequency band due to the use of shit-

registers. Therefore, greater power consumption, delay line without automatic control and with large

intersymbol interference degraded its performance. Discriminator intelligently detects the carrier even in



random FM noise conditions. Due to abrupt phase variations frequency discriminator detection is not reliable for

QPSK signals. Coherent detection [17] is suitable for mobile radio applications due to its low power

consumption and good BER performance in slow fading environment as compared to the differential detector.

However, it is difficult to apply it to burst signal transmission.

To overcome the problems in above three detection techniques, dual-mode carrier recovery (DCR) circuit was

designed. The DCR circuit adaptively selects one of two operation modes according to the fading environment:

one is the conventional Costas loop mode; and the other is the adaptive carrier-tracking (ACT) mode [18]. This

ACT mode controls the reference phase digitally, and enables instantaneous phase tracking in the carrier

recovery process [19]. Even under fast fading conditions, the BER of coherent detection using ACT is

equivalent to that of differential detection. In addition, ACT‟S instantaneous phase tracking characteristic is

applicable to fast carrier frequency acquisition in burst signal transmission. Therefore, for good BER

performance and application to burst signal demodulation, the DCR coherent demodulator is superior to a

conventional coherent demodulator or a differential detector [19].This will increase the complexity of the circuit

which increases the cost and complexity of algorithm for computations. Therefore need of demodulator which

offer less computations becomes necessary.

Similarly multiple-symbol differential detection (MSDD) was first proposed for detecting multiple phase-shift

keying (M-PSK) signals transmitted over an additive-white-Gaussian noise (AWGN) channel [20]. The main

advantage of MSDD is that it does not require a coherent phase reference at the receiver (it does require,

however, the ability to measure relative phase differences) [21]. MSDD performs maximum-likelihood

detection of a block of information symbols based on a corresponding observation interval [21]. The method

was presented as a bridge of the gap between the performance of coherent detection of M-PSK and conventional

differential detection of -ary differential phase-shift keying (M-DPSK) [20]. In the course of designing

simulations for evaluating MSDD it was realized that there is no efficient MSDD algorithm available for MSDD

with diversity [21]. The computational complexity of direct computation of the decision statistic grows

exponentially with the number of symbols in the observation interval [21].

The numbers of computations in discrete Fourier transform (DFT) can be reduced using Fast Fourier transform

(FFT). For computing one sample, we require N0 complex multiplications and N0 – 1 complex addition. In FFT

we take the value of N0 in the power of 2‟s.For large N0, this can be prohibitively time consuming, even for

high speed computer.

V. CONCLUSIONS Finally, it is concluded that the modified Binary Search Algorithm is an efficient approach for carrier acquisition

in DSB-SC communication System. The proposed algorithm proves more helpful for carrier acquisition process

as it is more accurate, low cost and less time consuming. Also, the computational complexity is very low,

instead of 80-82, needs only 13-14 multiplication for carrier acquisition.

References [1] H. Sari, S. Moridi, L. Desperben, and P. Vandamme, “Baseband equalizationand carrier recovery in

digital radio systems,” IEEE Trans.Commun., vol. COM-35, pp. 319–327, Mar. 1987.

[2] H. Sari and S. Moridi, “New phase and frequency detectors for carrier recovery in PSK and QAM systems,” IEEE Trans. Commun., vol. 36,pp. 1035–1043, Sept. 1988.

[3] Costas N. Georghiades, Senior Member, IEEE,” Blind Carrier Phase Acquisition for QAM Constellations,”IEEE Trans. Commun.,vol. 45, NO. 11, November 1997.

[4] Franjo Plavec, Zvonko G. Vranesic, Stephen D. Brown, “On Digital search trees, a Simple Method for Constructing Balanced Binary Trees,” Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, ON, Canada [email protected],[email protected],[email protected]

[5] Shynk, J.J., “Frequency-Domain and Multirate Adaptive Filtering,”IEEE Signal Processing Magazine, Jan. 1992, pp. 15-37.

[6] D. R. Bull and D. H. Horrocks, “Primitive operator digital filters,” IEE Proc.- G, vol. 138, no. 3, pp. 401-412, Jun. 1991.

[7] A. G. Dempster and M. D. Macleod, “Use of minimum-adder multiplier locks in FIR digital filters,” IEEE Trans. on Circuits and Syst.- II, vol. 42,no. 9,pp.569-577, Sep. 1995.

[8] R. I. Hartley, “Subexpression sharing in filters using canonic signed digit multipliers,” IEEE Trans. on Circuits and Syst.- II,vol. 43, no. 10, pp. 677-88, Oct. 1996.

[9] R. A. Hawley, B. C. Wong, T. J. Lin, J. Laskowski and H. Samueli, “Design techniques for silicon compiler implementations of high-speed FIR digital filters,” IEEE J. Of Solid-State Circuits, vol. 31, no. 5, pp. 656-666, May 1996.

[10] R. Paško, P. Schaumont, V. Derudder, S. Vernalde, “A new algorithm for elimination of common subexpressions,” IEEE Trans. on Computer-Aided Design, vol.18, no. 1, pp. 58-68, Jan. 1999.

[11] M. M. Peiró, E. I. Boemo, and L. Wanhammar, “Design of high-Speed multiplierless filters using a nonrecursive signed common subexpression algorithm,” IEEE Trans. on Circuit and Syst.-II, vol. 49, no. 3, pp. 196-203, Mar. 2002.

mailto:[email protected],[email protected],[email protected]



[12] M. Potkonjak, M. B. Srivastava, and A. P. Chandrakasan,“Multiple constant multiplicaitons: Efficient and versatile framework and algorithms for exploring common subexpression elimination,” IEEE Trans. on Computer-Aided Design, vol. 15, no. 2, pp. 151-165, Feb. 1996.

[13] S . M. Elnoubi, “Analysis of GMSK with differential detection in land 965-969 mobile radio channels,” IEEE Trans. Veh. Technol., vol. VT-35, pp. 162-167, Nov. 1986.

[14] M. K. Simon and C. C. Wang, “Two bit differential detection of narrow-band FM,” in Proc. Digest Globecom „84, pp. 740-745.

[15] M. K. Simon and C. C. Wang, “Differential versus limiter-discriminator detection of narrow-band FM,” IEEE Trans. Cornmun., vol.COM-31, pp. 1227-1234, Nov. 1983.

[16] M. Hirono, T. Miki, and K. Murota, “Multilevel decision method for band-limited digital FM with limiter-discriminator detection,”IEEE Trans. Veh. Technol., vol. VT-33, pp. 114-122, Aug. 1984.

[17] H. Suzuki, Y. Yamao, and H. Kikuchi, “A single-chip MSK coherent demodulator for mobile radio transmission,” IEEE Trans. Veh.Technol., vol. VT-34, pp. 157-168, Nov. 1985.

[18] H. Suzuki and S . Saito, “Adaptive carrier-tracking coherent detection for digital mobile radio transmission,” in Proc. In?. Conf. Digital Land Mobile Radio Commun., July 1987, pp. 94-103.

[19] Shigeski Saito and Hiroshi Suzuki, “Fast Carrier-Tracking Coherent Detection with Dual-Mode Carrier Recovery Circuit for Digital Land Mobile Radio Transmission,” IEEE journal on selected areas in communications, vol. 7. no. I , january 1989.

[20] D. Divsalar and M. K. Simon, “Multiple symbol differential detection of MPSK,” IEEE Trans. Commun., vol. 38, pp. 300–308, Mar. 1990.

[21] Debang Lao and Alexander M. Haimovich, “Multiple-symbol differential detection with Interference Suppression, ” IEEE Trans. Communications, vol. 51, no. 2, February 2003.





Medical image de-noising using Anisotropic Diffusion

Himali R. Bonde

1, Prof. S. A. More

2

1(E & TC, R. C. P. I. T. College of Engineering, Shirpur, India.)

2(E & TC, R. C. P. I. T. College of Engineering, Shirpur, India)

ABSTRACT : Image denoising is an important image processing task. Removing noise from the original

image is still a challenging problem for researchers. Several algorithms have been published and each approach

has its assumptions, advantages, and limitations. Wavelets give high quality results in image de-noising due to

properties such as sparsity and multi resolution. Images get reduced due to presence of noise when they are

retrieved, stored, transmitted or acquired. In this work, we give an idea to de-noise images by applying

anisotropic diffusion and multilevel Discrete Wavelet Transform (DWT) on different types of noise. The

different types of noise which we consider here are speckle noise and salt & pepper noise.

KEYWORDS -Anisotropic Diffusion, Multilevel Discrete Wavelet Transform (DWT)

I. INTRODUCTION This technique gives us a digital image such as medical or remote sensing image despeckling technique

using Anisotropic Diffusion method. Here we will apply this method on different noise such as salt & pepper

noise. This is a widely used and safe medical diagnostic technique. It is non-interfering in nature, cheaper, and

has capability of forming real time imaging along with improvements in image quality. The utility of ultrasound

imaging is deprived by the presence of signal dependent noise known as speckle. In this technique, a new

method for speckle reduction is explained. Here, a noisy image is decomposed into four 7 subbands in wavelet

domain considering 2 level wavelet transform. The low frequency subband contains the low frequency

coefficients having structural components with noise and high frequency subbands contain the high frequency

coefficients of texture components with noise that can be easily eliminated using Anisotropic Diffusion method.

Also, along with speckle noise, salt and pepper noise will be applied for testing and evaluation of signal to noise

ratio.

Fig 1: Tentative Model

The technique is compared with previous techniques as applied to simulated and unwanted parameters ie, mean

square error and peak signal to noise ratio will be calculated for performance evaluation.

II. LITERATURE OVERVIEW Image Denoising has remained a fundamental uncertainity in the stream of image processing.Various

algorithms for denoising in wavelet domain were introduced in the last two decades. The advantages and

usefullness of Wavelet Transform were better than Spatial and Fourier domain. Donoho’s Wavelet based

thresholding approach published in 1995 encouraged many others to publish papers in the denoising

domain.[18] Although Donoho’s work was not extraordinary, there was no requirement of tracking or

comparing and realting of the wavelet maxima and minima over the number of scales as described by Mallat. [3]

Number of ways of calculating the parameters for the thresholding of wavelet coefficients were published

by researchers. Also, a lot of effort has been invested in Bayesian denoising in Wavelet domain in recent

research. Gaussian Scale Mixtures and Hidden Markov Models have also become well known resulting in

publishing of more research work. There is a continued trend of focusing on using of different statistical models



for modelling the properties of the wavelet coefficients and its adjacent coefficients. In future, there will be a

trend directed towards investigating more accurate and probabilistic models for the distribution of non-

orthagonal wavelet coefficients.

Some more existing methods include total variation, wavelet and non-local means. The total variation

method uses geometric features of the image, gives close match to the original signal or image, remove

unwanted details while preserving important ones. The wavelet method utilizes the statistical features of the

coefficients but the major drawback is that it is time consuming. The non-local mean method employs the mean

value of group of pixels surrounding a target pixel to smooth the image.

III. WAVELET THEORY A. WAVELET TRANSFORM

The Wavelets are known as DWT when they are sampled discretely. DWT is a multi-resolution

decomposition structure. Utilizing DWT the primary image is decomposed into two subspaces of low frequency

sub band and high frequency sub band. At every iteration of the DWT, the lines of the input image (obtained at

the cessation of the precedent iteration) are high-pass filtered with a filter H and low-pass filtered with the filter

L. There are two filters are decimated with a factor of two when the lines of the two images are obtained at the

output. Then, the two columns of the images are low-pass filtered with L and high-pass filtered with H. The

columns of those four images are additionally decimated with a factor of 2. This results in four incipient sub-

images. The first sub image is denominated LL image or approximation sub-image. The other three are called

detail sub-images: LH, HL and HH. For the next utterance, input is represented by LL image. In the given

coefficients of DWT noted with 𝑖𝐷𝑙𝑚, 𝑖 represents the image. The resolution level or iteration represented by 𝑚

and 𝑙=1 for HH image, 𝑙=2 for HL, 𝑙=3 for LH and 𝑙=4 for LL image. These coefficients are computed using eq.

(1) to eq.(2). [1]

),(),,(],[ 21,,21 l

pnm

l

m ipniD (1)

where we can factorize the wavelets as:

)().(),( 2,,1,,21,, l

pnm

l

pnm

l

pnm (2)

Using the proceeding relations and the scale function (𝜏) and mother wavelet (𝜏), the two factors can be

computed using eq. (3) to eq. (4).

3,2,

4,1,

,

,

,,l

l

nm

nml

pnm

(3)

3,1,

4,2,

,

,

,,l

l

nm

nml

pnm

(4)

Where,

nmm

nm 22 2

, (5)

nmm

nm 22 2

, (6)

B. DISCRETE WAVELET TRANSFORM Discrete wavelet transform (DWT) is multiresolution decomposition of a signal. The low pass filter applied

along a specific direction obtains the low frequency coefficients and the high pass filter obtains the high

frequency coefficients of signal. [4]

In 2D applications, for every level of decomposition, the DWT is first performed in the vertical direction,

followed by the DWT in the horizontal direction. After the first level of decomposition, there are 4 sub-bands:

LL1, LH1, HL1, and HH1. For next each successive level of decomposition, in our approach the LH sub band of

the precedent level is utilized as the input. Three levels of decomposition are performed on each component.



LH1, HL1, and HH1 contain the highest frequency bands present in the image section, while LL3 consists the

lowest frequency band. [4]

Fig 2: Three level DWT decomposition

IV. ANISOTROPIC DIFFUSION It is a type of noise filtering technique. It was developed by Perona-Malik in 1987 and hence also called as

Perona-Malik diffusion. It aims at reducing noise without removing significant parts of the image content,

typically edges, lines or other details that are important for the understanding of the image.Anisotropic diffusion

resembles the process that creates a scale space, where an image generates a parameterized family of

successively more and more blurred images based on a diffusion process. This diffusion process is a non linear

and space variant transformation of the original image.

V. ARTIFICIAL NEURAL NETWORK ANN is similar to a biological neural network with a very competent information processing system. The

special characteristics of ANN are its ability to learn, recall and generalize data and training patterns akin to that

of human brain. Artificial Neurons or Neurons are the processing components of ANN and they are operated in

parallel. [1]

ANN can be classified into two classes, namely Feed Forward and Feed-Back (FB). This classification is

predicated on training pattern and network configurations. Here, we will focus on Feed Forward ANN. Here, the

response is generated by processing the information in a forward pass. The weight and bias values for every

neuron in this network is then upgraded by utilizing the back propagation supervised learning algorithm. [14]

Fig 3: Architecture of FF ANN

A specific type of FF network known as Multi-Layer Perceptron (MLP) uses three or more layers of

neurons. For non-linearly separable data they are able to co-relate training patterns with outputs. Fig 2 shows, an

architecture of Feed Forward ANN.

VI. NOISE Image noise is a random and unwanted variation of the information content of the image, and is generally

an aspect of electronic noise. It can be produced by the sensor and circuitry of a scanner or digital camera.

Image noise is an undesirable by-product of image capture that adds false and intrusive information.

Speckle noise

https://en.wikipedia.org/wiki/Anisotropic

https://en.wikipedia.org/wiki/Scale_space

https://en.wikipedia.org/wiki/Diffusion_process

https://en.wikipedia.org/wiki/Electronic_noise

https://en.wikipedia.org/wiki/Sensor

https://en.wikipedia.org/wiki/Image_scanner

https://en.wikipedia.org/wiki/Digital_camera



Speckle noise in an image means that some extra and unwanted pixels added in the image while taking a

photograph through a digital camera. This degrades image quality and increases the size of image.

Salt and pepper noise

Salt and pepper noise is mostly seen on black and white images. it gives a grainy texture to image.

VII. RESULTS We calculate the value for Root Mean Square Error (RMSE), Peak Signal to Noise Ratio (PSNR) and

Entropy for de-noised image. The calculated values apply for both types of noises i.e speckle noise and salt &

pepper noise using equations,

MSEPSNR

2

10

maxlog10

Where,

21

0

1

0

),(),(1

n

j

m

i

jiKjiImn

MSE

Here, l is noisy image and K is the denoised image. m and n represent the dimensions of the images and max is

the maximum pixel value.

TABLE 1 PSNR OF IMAGE-I WITH DIFFERENT NOISES FOR NOISE LEVELS 0.01

Types of noise RMSE PSNR Entropy

Salt &pepper 5.40 40.80 7.10

Speckle 3.96 42.14 6.93

Fig 4: Noisy

&De-noised Image with salt&pepper noiseFig 5: Noisy& De-noised image with speckle noise



Salt &pepper 17.85 35.61 7.18

Speckle 11.51 37.51 6.92

Fig 6:

Noisy &De-noised Image with salt&pepper noiseFig 7: Noisy& De-noised image with speckle noise





Salt &pepper 28.31 33.61 7.25

Speckle 15.89 36.11 6.91

Fig 8: Noisy &De-noised Image with salt&pepper noiseFig 9: Noisy& De-noised image with speckle noise

TABLE 4

PSNR OF IMAGE-Il WITH DIFFERENT NOISES FOR NOISE LEVELS 0.01


Salt &pepper 6.99 39.68 6.94

Speckle 4.04 42.06 6.92

Fig 10: Noisy

&De-noised Image with salt & pepper noise Fig 11: Noisy & De-noised image with speckle noise

TABLE 5

PSNR OF IMAGE-I WITH DIFFERENT NOISES FOR NOISE LEVELS 0.02


Salt &pepper 6.75 39.83 6.96

Speckle 5.26 40.91 6.93

Fig 12: Noisy

&De-noised Image with salt &pepper noiseFig 13: Noisy & De-noised image with speckle noise



TABLE 6

PSNR OF IMAGE-I WITH DIFFERENT NOISES FOR NOISE LEVELS 0.03


Salt &pepper 7.56 39.34 6.99

Speckle 5.93 40.39 6.94

Fig 14:Noisy &De-noised Image with salt & pepper noiseFig 15:Noisy & De-noised image with speckle noise

VIII. CONCLUSION The scope always exists for exploring innovative denominates of performing de-noising for enhancing

image quality. Considering the precedence of image de-noising here, we present an approach to de-noise the

images which is errored by the presence of noise. In this work we put together the advantages of anisotropic

diffusion and DWT to obtain a competent image de-noising algorithm. Here, we utilize various test images, for

speckle and salt and pepper noise with different noise level ranges. Our calculations are based on PSNR and

Entropy. The PSNR of speckle noise is greater than that of salt and pepper noise. Whereas, Entropy levels are

lower for speckle noise than salt and pepper noise.

REFERENCES [1]. Torali Saikia, Kandarpa Kumar Sarma, “Multilevel DWT based Image De-noising using Feed Forward

Artificial Neural Network.”, IEEE, vol 978-1-4799-2866-Aug 2014.

[2]. M. Kaur and R. Sharma, “Restoration of Medical Image Using Denoising”, International Journal for

Science and Emerging Technologies with Latest Trends, vol. 5, no. 1, pp. 35-38, 2013.

[3]. M. H. Krishnan and R. Viswanathan, “A New Concept of Reduction of Gaussian Noise in Image Based

on Fuzzy Logic”, Applied Mathematical Sciences, vol. 7, on. 12, pp. 595-602, 2013.

[4]. Satendra Kumar, Ashwini Kumar Saini, Papendra Kumar ” SVD based Robust Digital Image

Watermarking using DWT”, International Journal of Computer Applications, Vol. 45-No. 10, May 2012.

[5]. Y. A. AL. Sbou, “Artificial Neural Networks Evaluation as an Image Denoising Tool”, World Applied

Sciences Journal, vol. 17, no. 2, pp. 218-227, 2012.

[6]. A. Vishwa and S. Sharma, “Speckle Noise Reduction in Ultrasound Image by Wavelet Thresholding”,

International Journal of Advanced Research in Computer Science and Software Engineering, vol. 2, no.

2. 2012.

[7]. A. S. Ufade, B. K. Khadse and S. R. Suralkar, “Restoration of Blur Image Using Wavelet based Image

Fusion”, International Journal of Engineering and Advanced Technology, vol. 2, no. 2. Pp. 159-161,

2012.

[8]. Kanika, N. Dhillon and K. Sharma, “Comparative Analysis of Discrete Wavelet Transform and Fast

Wavelet Transform on image Compression”, International Journal of Engineering Research and

Technology, vol. 1, no. 5, pp. 1-7, 2012.

[9]. M. Kaur and D. Mandal “Speckle Noise Reduction in Medical Ultrasound Image using Particle Swarm

Optimization with Artificial Neural Networks”, International Journal of Electronics and Communication

Technology, vol. 2, no. 3, pp. 147-150, 2011.

[10]. N. K. Ragesh, A. R. Anil and R. Rajesh, “Digital Image Denoising in Medical Ultrasound Image: A

Survey” International Journal on Artificial Intelligence and Machine Learning, pp. 67-73, 2011.

[11]. S. D. Ruikar and D. D. Doye, “Wavelet Based Image Denoising Technique”, International Journal of

Advanced Computer Science and Applications, vol. 2, no. 3, pp. 49-53, 2011.

[12]. K kaur, A. Chanda and P. Karmarkar,”An Unique Edge Preserving Noise Filtering Technique for

Impusive Noise Removal ”, An International Journal on signal and Image Processing, vol. 2, no. 3, pp.

33-46, 2011.

[13]. K. G. Karibasappa, S. Hiremath and K. Karibasapps, “Neural Network Based Noise Identification in



Digital Image”, The Association of Computer Electronics and Electrical Engineers International Journal

on Network Security, vol. 2, no. 3, pp. 28-31, 2011.

[14]. J. Jiang, P. Trundle and J. Ren, “Medical Image Analysis with Artificial Neural Networks”,

Computerized Medical Imaging and Graphics, vol. 34, no. 8, pp. 617-631, 2010.

[15]. R. C. Gonzalez, “Digital Image Processing”, 4th

edition, Pearson Education India, 2009.

[16]. J. Kaur, M. Kaur, P. Kaur and M. Kaur, ”Comparative Analysis of Image Denoising Technique”,

International Journal of Emerging Technology and Advanced Engineering vol. 2, no. 6, pp. 296-298,

2012.s

[17]. S. Abbasi, F. Mokhtarian, J. Kittler, Reliable classification of chrysanthemum leaves through curvature

scale space, B. ter Haar Romeny, L. Florack, J. Koenderink, M. Viergever (Eds.), Scale-space theory in

computer vision, Lecture Notes in Computer Science, Vol. 1252, Springer, Berlin, 284–295, 1997.

[18]. M. C. Motwani, M. C. Gadiya, R. C. Motwani and F. C. Harris, “Survey of Image Denoising

Techniques”.

[19]. Imola K. Fodor, Chandrika Kamath, “Denoising Through Wavlet shrinkage: An empirical study”, Center

for applied science computing Lawrence Livermore National Laboratory, July 27, 2001.

[20]. D. L. Donoho, “De-noising by soft-thresholding” IEEE Trans. Information Theory, vol. 41, no. 3, pp.

613-627, May 1995.

[21]. S. G. Mallat and W. L. Hwang, “Singularity detection andprocessing with wavelets”, IEEE Trans. Inform

Theory, vol. 38, pp. 617-643, Mar 1992.





Genetic potential evaluation of Binbei area in the Songliao Basin

Dai xiaojuan

College of earth science of Northeast Petroleum University, Daqing, Heilongjiang, China.

Abstract: After many exploration，Binbei area in the Songliao Basin，with large oil and gas exploration

potential，is the key exploration area at present. Through the existing data of Binbei area, combining previous

research results, this article will give a brief introduction of oil-generation condition in Binbei area.

Keywords: Beibei area, exploration potential, oil-generation

1. The tectonic characteristics and development Combined with previous studies and based on regional geology and basin geology,the evolution of Beibei

area can be divided into six evolutionary stage, include extrusion, the volcano-down faulted basin, fault

depression, fault depression transformation, subsidence and shrinking balance stage.

After the shrinking balance stage, the basin comprehensively rise and the lake basin massively shrink. In

the overall rising background, the eastern of basin uplift differently, the Sifangtai Formation and Mingshui

Formation’s sedimentary shore back to the west region, the deposition rate becomes slow, and the tectonic

movement becomes passive. Under the system of extrusion stress, the basin thrusts to the northwest and forms

extrusion anticline belt of tectonic inversion phenomenon with the inner part in the southeast area.

Paleocene-Miocene(65-9Ma;especially between 50 and 15Ma),the pacific plate become oblique subduction to

the northwest, lead to the east margin of the Eurasian plate under pressure torsion stress field and the boundary

faults in the right-lateral strike-slip state. Under the pressure of torsional stress system, phenomenon appears that

the inner part of the basin thrusts to the northeast and the tectonic inverse. On the basis of erosion, tertiary and

quaternary system is a kind of molasse formation, when the activity is weak and the basin shows the

characteristics of the demise gradually.

2. Oil producing formation in Binbei area

Binbei area is located in the large fresh water lake basin sedimentary environment, near the northern

provenance of Songliao basin.Qingshankou Formation and the first and second member of Nenjiang Formation

belong to deep lake facies, dark mudstone is relatively development and is the main oil producing formation.

From the point of plane distribution, the first and second member of Nenjiang Formation is widespread,

then is the first member of Qingshankou Formation and the second and third member of Qingshankou

Formation, the rest of the group is small. From the source rock volume, the second member of Nenjiang

Formation is the largest, followed by the second and third member of Qingshankou Formation, and the last is

the first member of Qingshankou Formation.

3. The qualitative evaluation of the source rocks Source rock is the material basis for the oil and gas generation. The purpose to study the qualitative

evaluation of the source rocks is to explain the existence of the source rocks in the area, development situation

and its quality, and the most important parameters are: organic matter type, organic matter maturity and so on.

3.1 Organic matter type

It is known form the application of element analysis data, qn1 Member and n1 Member sample distribution

inⅠ、Ⅱ zone，qn2+3 Member exist in bothⅠzone andⅡzone. Overall, qn1 Member and n1 Member have a



better Organic matter type (Fig1).

Fig1 The H/C - O/C curve of Binbei area

3.2 Organic matter maturity

Among the entire indicator that reflects the organic matter maturity, the vitrinite reflectance (Ro) is the most

widely used and the most authoritative. Classic hydrocarbon accumulation patterns thought Ro from 0.5% to

0.7% is the corresponding oil threshold and Ro from 0.5% to 0.7% - 1.3% correspond to the main oil region.

Fig2 Ro histogram of different source rocks in Binbei area

From the distribution histograph of n1,n2,qn1,qn2、3 in Binbei area(Fig2) ,we know that shallow source

rock maturity is generally not high, most of the samples of Ro are below 0.9%.The maturation of organic matter

of the main hydrocarbon source layer is lower, which is generally lower than that of low mature stage, that is the

key factor restricts the region’s oil and gas exploration.



3.3 Oil threshold

It is generally believed that hydrocarbon source rock oil threshold of Ro is from 0.5% to 0.7% . If the

Ro=0. 5% as oil threshold, from the Ro and depth relationship curve (Fig3) in the area, a certain threshold depth

is very shallow, about 1150 m or so. Therefore, previous determining oil threshold may be based primarily on

this.

Predecessors thought it needs less energy to destroy atomic bonds (like C-C、C-H) of organic matter type I

than that of organic matter typeⅡ、Ⅲ. So give priority to with Ⅰtype organic matter of the main source area of

Songliao basin, the main source rock oil threshold corresponds to the Ro is 0.5%. More and more mainstream,

more authoritative opinion, to the contrary. Such as Tissot P B, Welte P H think Ⅰkerogen oil threshold

temperature is the highest, the corresponding vitrinite reflectance can reach 0.7%;Ⅱtype oil threshold

temperature is minimum, Ro for 0. 5%; Hydrocarbon source rocks in Binbei area are I type more. Accordingly,

its oil threshold should correspond to the Ro = 0.7%.

Fig3 The relationship between vitrinite reflectance and depth in Binbei area

Such determined by Fig3 threshold depth is 1600 m or so, main oil generating range between 1700-2350

m.

4. Conclusion

(1)The most development dark mudstone in Binbei area is the second and third member of Qingshankou

Formation, followed by the first and second member of Nenjiang Formation.

(2) The main source rock organic matter type is better, mainly isⅠ, Ⅱ type.

(3) The organic matter maturation of main source rocks is lower, generally located in the low mature stage; it is

the key factor that restricts the oil and gas exploration in this region.



Reference:

[1]. Huang Futang. Research on the distribution of nature gas in the north part of Songliao Basin [J].Natural Gas

Geoscience, 1995, 32(6):36-40.

[2]. Cai Xiyuan, Chen Zhangming.Petroleumgeology analysis on two rivers area, Songliao Basin [M]. Beijing

Petroleum Industry Press, 1999.

[3]. Fu Guang, Lu Shuangfang, Li Hongtao.Hydrocarbon potential forecast of Fuyang reservoir in Binbei area

[J]. Petroleum Geology and Recovery Efficiency, 2003, 10 (5):25-29.

[4]. Luo chao. The characteristic analysis and evaluation of source rocks in the mid-shallow strata of Binbei

region in Songliao Basin [J]. Inner Mongolia petrochemical industry, 2010(5):136-139.

[5]. Zhao bo. Sedimentary facies and sedimentary evolution of the Upper Cretaceous Qingshankou Formation

of Binbei area in Central Depression of Songliao Basin [J].Journal of palaeogeogrephy,2009,

11(3):293-300.

[6]. Wang Yaowen. Estimation of biogas resources in Binbei area in the Songliao Basin. Natural Gas Induatry,

2006, 26(7):18-21.





Effect of Biogenic Silica Soil Conditioner on Paddy Crop in

India

S. T. Buddhe1, M.G. Thakre

2, Sanyogita Verma

3 and P.R. Chaudhari

4

1 Biocare (India) Pvt. Ltd., Shewalkar Garden, Block no. 57/57A, Wing “E”, Opposite V.N.I.T. main gate, S.A.

Road, Gopal Nagar, Nagpur 440009, India 2 Department of Environment Science, Arts, Science and Commerce college, Tukum, Chandrpur 442401

3. Anand Niketan College, Anandwan, Warora, Maharashtra (India)

4. Grass Roots Research and Creation India (P) Ltd., F-374-375, Sec. 63, Noida 201301, Uttar Pradesh, India;

(ex-Deputy Director and Scientist, National Environmental Engineering Research Institute, Nagpur 440020)

Abstract: Now-a-days various soil conditioners are being discovered and used in agriculture to increase soil

fertility and crop productivity. Different soil conditioners are being used in this direction to improve the food

production from the poor and medium soils. In this category, a new product, diatomaceous earth - Biogenic

Silica, having the characteristics of good soil conditioner, is now studied in this article to improve the nutrient

status and productivity of the soil of paddy field at Jabalpur, India. The results of one season field experiments

showed significant improvement in the nutrient content of paddy field soil of medium fertility, and improvement

in the yield attributes like plant population (119 plants/m2), tillers (279/m

2), effective tillers (256/m

2), grains

(163/panicle), test weight (21.28 g) and panicle length (24.42 cm). Similarly, grain yield (max. 45.74 q/ha) and

straw yield (max. 92.49 q/ha) of rice were improved significantly by application of Biogenic Silica at the dose

of 500 kg/ha separately both at transplantation stage and at full bloom stage of rice crop. The improvement in

soil nutrients over initial values was up to maximum 2% in soil nitrogen, 42.25% in case of phosphorus and

3.2% in potassium content.

Key Words: Diatomaceous Earth, Paddy, Productivity, Soil Fertility

INTRODUCTION Ever increasing population in the world, accompanied by decreasing per capita arable land, has ringed the bell to

increase the production of food from the available land. Various technological interventions are being used to

improve the yield of crop. Use of novel soil conditioners is one of these techniques to improve the fertility and

quality of agricultural soils and to improve the productivity of land. Diatomaceous earth, which is Biogenic

Silica (BS) derived from diatoms, has attracted the attention of a few researchers as potentially promising

product for use in agriculture. Presently, it is being used in the garden as natural pest control substance. A few

references are available on the use of BS as soil conditioner for turf grass growth and used as top dressing

(Wehtje et al., 2003; Waltz and McCarty, 2000) while there is no reference on crops from India. Brown (2013)

who has shown experimentally that diatomaceous earth spent cake from filters can be used as fertilizer to

improve the growth of crops. He has reported that the BS has favorable physicochemical properties as soil

conditioner. In this research paper, Biogenic Silica is used in India for the first time as novel soil conditioner for

studying its favorable impact on soil fertility and growth and yield of paddy.

MATERIALS AND METHODS The Biogenic Silica was securely collected from the mining area. The field experiment on paddy crop was

carried out during 2014. The transplantation of paddy was carried out on 14th

July 2014 (rainy season) at

Jabalpur, India having black soil. In Experimental Set-1, the different doses of Biogenic Silica at 250 kg/ha, 375

kg/ha and 500 kg/ha were applied to paddy field soil before transplantation. In Experimental Set II, Biogenic

Silica dose of 500 kg/ha was applied separately to the soil of rice field at each of three different stages of paddy

crop. At Stage I (T1), Biogenic Silica was applied at the time of vegetative growth (VG) (30-35 days after

sowing); at Stage II (T2), it was applied at the time of full bloom (FB) (Flowering stage) and; at Stage III (T3),

it was applied at the time of development stage of grains in panicles. All the experimental plots of paddy field

were also applied with recommended dose of fertilizer (RDF) (120:60:40 kg NPK/ha). The treatments were

given in different experimental plots in the paddy field. Paddy variety IR-64 was selected as rice cultivar. The

soil in the field was subjected to excessive dispersion during puddling, resulting into drastic change in their pore

size distribution. The paddy crop was harvested on 12th

November 2014.

A total of six treatments over 18 plots were arranged in a completely randomized design and each treatment was

carried out in three replications (6x3=18). The gross and net plot sizes were 5m x 3.6 m and 4 m x 3.2 m

Effect of Biogenic Silica Soil Conditioner on Paddy Crop in India


respectively. The distance between the replications was kept at 1.5 m and the distance between the rows was

kept at 20 cm. The powder form of Biogenic Silica was applied to paddy field soil at proper doses and mixed

mechanically within 15 cm depth of the surface soil. The basal RDF dose applied into soil two days before rice

transplanting was given as: nitrogen (50% dose), phosphorus (100% dose), and potash (100% dose). Each dose

of top dressing fertilizer (nitrogen 25%) was added after one and two months of transplanting. Water level was

controlled at around 5-7 cm depth during the cropping season and rice was harvested 150 days after

transplantation. Soil was collected from the test field from 30 cm depth from three places from each treatment

before sowing and after harvest, air dried, sieved (<10mm). Pre-sowing soil was analyzed for physicochemical

parameters to evaluate the quality and nutrient content of soil. Post-harvest soil was analyzed for nutrient

content (Jackson, 1973) to evaluate the effect of Biogenic Silica on nutrient content of soil wiz. available

nitrogen (N), available phosphorus (P), and available potassium (K). At pre-harvest stage, the observations on

crop were recorded on plant population/m2 and number of tillers/m

2; and at Post-harvest stage on Effective

tillers/m2, number of grains /panicle, test weight (g), grain yield (q/ha), and straw yield (q/ha).

RESULTS AND DISCUSSION Project Site

Jabalpur from Madhya Pradesh, India has humid subtropical climate. Summer starts in late March and lasts up

to June. May is the hottest month with average temperatures reaching up to and beyond 450C. Summer is

followed by monsoon season, which lasts until early October, with a total precipitation of nearly 55 inches

(1386 mm). Winter starts in late November and lasts until early March. The cold peaks in January with average

daily temperature near to 150C.

Biogenic Silica

The Biogenic Silica is naturally occurring, soft, chalk-like sedimentary rock that is easily crumbled into a fine

white to off-white powder. It is very light due to its high porosity. It consists of fossilized remains of diatoms

(Fresenberg, 1999), a type of hard-shelled algae, which is also heat-resistant. The diatoms pull silica acid of

water and store large amount of crystallized silica in their outer walls. When diatoms die, much of silica

dissolves back into water and rest of it collects in sediments to be recycled by geologic forces. Eventually some

of the silica returns to the land in pure pockets. The silicates mined from these clean, rich deposits are useful for

farmers, providing both water soluble and flowable silica in a form that is beneficial to plants and plant growth-

promoting microorganisms.

Chemically, BS is like silica sand in that it consists of about 90% silica (SiO2) with minor amounts of alumina

(Al2O3) (Mannion, 1996). BS is porous, thus have low densities and can retain water up to 150% of its weight

while draining fast and freely allowing high oxygen circulation within the growing medium and beneficial

nutrient for plant growth. BS improves the uptake of water and minerals and adds an extra level of protection

against fungal diseases such as powdery mildew. The BS has sharp edges that tear up insects crawling over

them. BS is the reservoir of plant-available silica and nutrients and trace elements. Freshwater diatomite is

typically food-grade due to its fine particle size and low silica content and is typically the variety used for

consumption, health products and pest control. Saltwater BS should not be used in the same way due to its high

silica content.

Paddy Field Soil Quality before Transplantation

The soil of experimental field before the transplantation of paddy seedlings was observed to be clayey in texture

(however with excess clay) (Table I), with ideal electrical conductivity (EC) & pH; medium-low organic carbon,

medium potassium; low nitrogen and very low phosphorus as per the guidelines for rating the soil fertility

indicators in India (Table II) (Tandon, 2005) and also the guidelines given by Utah State University in

cooperation with U.S. Department of Agriculture (Table III). It is concluded that the soil is of medium fertility

level. This low content of P in the Jabalpur soil is in conformity with the report (Chandy, 2013) that medium

black soils of semi-arid regions have a medium fertility level with respect to phosphorus. The reason for

medium-low N is the medium organic carbon content of soil. Soil organic carbon has role in improving and

maintaining soil fertility, structure, stability, nutrient retention & restricting soil erosion (Singh, 2008).

Improvement of Available Nutrients in Soil The Experimental Set I screening experiment carried out on application of different doses of Biogenic Silica to

paddy field at the time of transplantation showed encouraging results in improving the nutrient content of the

paddy field soils over their initial value (Table IV, Figure 1 & 2). All the doses of Biogenic Silica improved the

phosphorus content significantly ranging from 38.72% to 42.17%, highest being in 500 kg/ha dose. Similarly,

percentage improvement in potassium content over initial was observed from 0.81% to 2.02%, and was in

increasing order with increasing doses of Biogenic Silica, highest being in 500 kg/ha dose. In case of nitrogen

content, 375 kg/ha dose of Biogenic Silica showed highest improvement by 1.08% over its initial value.

http://en.wikipedia.org/wiki/Humid_subtropical_climate



In Experimental Set II, the results of separate applications of 500 kg/ha Biogenic Silica at different stages of

paddy crop life cycle (Table IV, Figure 1 & 2) showed highest improvement in the content of all nutrients when

500 kg/ha Biogenic Silica was applied at full bloom stage. The percentage improvement over initial value was

2.00% in nitrogen, 42.25% in phosphorus and 3.2% in case of potassium.

Similar results were obtained by Southern Cross University in Australia, where the moisture retention and

nutrient level of the soil were significantly improved and leaching of any fertilizer was greatly reduced by BS

application. It was also seen that addition of BS to soil amended with fertilizer may allow for more efficient use

of fertilizer and reduce leaching of nutrients (Absorbent Products, [email protected], browsed on

1st November 2015).

Improvement in Yield Attributes and Yield of Rice

The results of the Experimental Set I on effect of different doses of Biogenic Silica application in paddy field

soil at the time of transplantation (Table V) showed that all the yield parameters of rice showed improvement in

all doses of Biogenic Silica. The improvement was directly proportional to the increase in Biogenic Silica

concentration; the range of improvement was observed as population (116 to 117 Plants/m2), tillers (251 to 261

tillers/m2), effective tillers (230 to 241 effective tillers/m2), grains (144 to 155 grains/panicle), test weight

(19.86 g to 21.23 g) and panicle length (22.36 cm to 23.82 cm). These results showed that the Biogenic Silica

dose of 500 kg/ha is optimum to increase the yield attributes of the rice.

The results of the Experimental Set II on the effect of Biogenic Silica dose of 500 kg/ha on the yield parameters

are shown in Table V. It was observed that all the yield parameters were improved at application of 500 kg/ha

Biogenic Silica at full bloom stage to the paddy field soil. The highest values of yield parameters at full bloom

stage application were observed as plant population (119 plants/m2), tillers (279 tillers/m2), Effective tillers

(256 effective tillers/m2), grains (163 grains/panicle), test weight (21.28 g) and panicle length (24.41 cm). It is

also observed that the yield parameters were best improved at Biogenic Silica (500 kg/ha) application at

transplantation stage which is next to application of Biogenic Silica (500 kg/ha) at bloom stage. Thus, it is

evident that application of Biogenic Silica dose at 500 kg/ha at transplantation and at full bloom stage would

give best results in improving yield attributes of paddy crop.

Similar trend of results were obtained in case of grain yield and straw yield of paddy crop (Table VI). Results

of doses of Biogenic Silica application (Experimental Set I) at transplantation stage indicated gradual increase in

the grain and straw yield of rice with increase in doses of Biogenic Silica from 250 kg/ha to 500 kg/ha. The

highest yields at 500 kg/ha dose were 43.38 q/ha of grains and 90.37 q/ha of straw. Similarly, the application of

Biogenic Silica at 500 kg/ha at full bloom stage (Experimental Set II) showed highest grain yield of 45.74 q/ha

and straw yield of 92.49 q/ha. The yields Biogenic Silica (500 kg/ha) at transplantation stage and at full bloom

stage are very much near to each other and highest among all treatments. Thus, application of Biogenic Silica

(500 kg/ha) at transplantation stage and at full bloom stage is optimum to improve the yield attributes and grain

and straw yield of paddy crop.

Conclusion The results showed that the optimum dose of Biogenic Silica is 500 kg/ha for improvement of yield attributes

and yield of paddy crop. This dose when applied at transplantation stage and at full bloom stage was observed to

improve the nutrient content of paddy field soil especially the phosphorus content as well as the yield attributes

and yield of paddy. The Biogenic Silica is observed to have good potential as soil conditioner at very low doses.

More experiments are desirable to study the suitability of Biogenic Silica for different types of soils, different

crops and under different climatic conditions.

Acknowledgement The authors wishes to thank all the members of team who have helped during the field study on paddy crop.

References [1]. Brown Julie, 2013. Recycling diatomaceous earth spent cake from filtration into a fertilizer. Industrial

Minerals Today. http://blog.epminerals.com/recycling -diatomaceous-earth-spent-cake-from filtration-into-

a-fertilizer.

[2]. Chandy, K.T., 2013. Status of plant nutrients in Indian soil. Online article, browsed 2013,

Booklet no. 71, Soil Sci.: SSS – 20. Agric. and Env. Education.

[3]. Fresenburg, B.S., 1999. Soil amendments for Missouri athletic fields: Infield soils and topdressings. In

Turfgrass: 1999 Research & Information Report [Missouri]. p. 7-8.

[4]. Jackson, M.L., 1973. Soil Chemical Analysis. Prentice Hall India: Bombay.

[5]. Mannion, B., 1996. Top dressing and aeration strategies. California Fairways. 5(4):24-30.

mailto:[email protected]

http://blog.epminerals.com/recycling



[6]. Singh, M.V., (Project Coordinator) (2008) Micronutrient fertility mapping for Indian soils. All India

Coordinated Res. Project of Micro and Secondary Nutrients and Pollutant Element in Soils and Plants,

Indian Inst. of Soil Sci. (ICAR), Bhopal

[7]. Tandon, H.L.S. (Ed), 2005. Methods of analysis of soils, plants, water, fertilizers and organic manure,

FDCO, New Delhi.

[8]. Waltz, C. and McCarty, B., 2000. Soil amendments affect turf establishment rate. Golf Course Manage.

68(7):59-63.

[9]. Wehtje, G.R., Shaw, J.N., Walker, R.H. and Williams, W., 2003. Bermuda grass growth in soil

supplemented with inorganic amendments. Hortscience. 38(4):613-617.

Table I: Qualitative Ratings of Soil Nutrients in Experimental Fields before Sowing

Description Sand Silt Clay Texture pH EC

(dS/m)

Organic

carbon

(%)

Available plant nutrients

(kg / ha)

N P K

Nutrient

content 25.18 19.18 55.64 Clayey 7.1 0.31 0.54 266 12.45 293

Qualitative

Ratings Ideal Ideal

Un-

Accepta-

ble

Accepta-

ble Ideal Ideal

Medium

Low Low

Very

Low Medium

Table II: Soil Fertility Classification Followed in Maharashtra & Some Other States

Soil fertility

level

Organic

Carbon (%)

Available

N (kg/ha)

Available P2O5

(kg/ha)

Available K2O

(kg/ha)

Very High >1.00 >700 >80.0 >360

High 0.81-1.00 561-700 64-80 301-360

Medium 0.61-0.80 421-560 48-64 241-300

Medium

Low

0.41-0.60 281-420 32-48 181-240

Low 0.21-0.40 141-280 16-32 121-180

Very Low <0.20 <140 <16.0 <120

Source: Tandon (2005)

Table III: Guidelines Category of Soil Parameters for the Growth of Crops

Category

Soluble

Salts (EC)

(dS/m or

mmho/cm)

pH Sand

(%)

Silt

(%)

Clay

(%)

Texture

Class*

Organic

Matter

(%)

% Coarse

fragments

(>2 mm in

diameter)**

Sodium

Adsorption

Ratio

(SAR)*

Ideal <3

5.5

to

7.5

<70 <70 <30 L, SiL ≥2.0 ≤ 2 <3 for any

texture

Acceptable <4

5.0

to

8.2

<70 <70 <30

SCL,

SL, CL,

SiCL

≥1.0 2.1 to 5.0

3 to 7

(SiL, SiCL,

CL)

3 to 10

(SCL, SL,

L)

Un-

acceptable >4

<5.0

or

>8.3

>70 >70 >30

LS, SC,

SiC, S,

Si, C

<1.0 5.0 10 for any

texture

Source: Utah State University Cooperation with the U.S. Department of Agriculture under Cooperative

Extension Work (AG/SO-02, 2002) [S: Sand; Si: Silty; C: Clay; L: Loam; LS: Loamy Sand; SL: Sandy Loam;

SCL: Sandy Clay Loam; CL: Clay Loam; SiCL: Silty Clay Loam; SC: Sandy Clay; SC: Silty Clay; SiC: Silty

clay; SiL: Silty loam]



Table IV: Effect of Biogenic Silica Application on Soil Nutrient Content as Influenced by Different

Doses of Biogenic Silica and Time of Application

Treatments Dose/Time of

Application

Nitrogen Phosphorus Potassium

Nutrient content (kg/ha) and Percentage Increase / Decrease

Pre-Sowing Content 266 12.45 293

Experimental Set I:

Application of different

Biogenic Silica doses at the

time of transplantation

250 kg/ha 264.76

(-0.47%)

17.27

(38.72%)

295.37

(0.81%)

375 kg/ha 268.86

(1.08%)

17.52

(40.72%0

297.13

(1.41%)

500 kg/ha 267.5

(0.56%)

17.7

(42.17%)

298.91

(2.02)

SEm± 1.02 0.4 0.82

CD at 5% 3.08 NS 2.47

Experimental Set II:

Separate application of

Biogenic Silica at 500 kg/ha

dose at different stages of

crop life cycle

At vegetative

growth stage

266.55

(0.21%)

17.67

(41.93%)

299.12

(2.09%)

At full bloom

stage

271.32

(2.00%)

17.71

(42.25%)

302.36

(3.20%)

At grain

development

stage

263.25

(-1.03)

17.11

(37.43%)

289.94

(-1.04%)

SEm± 1.02 0.41 0.82

CD at 5% 3.08 NS 2.47

Table V: Effect of Biogenic Silica Application on Yield Attributes of Rice as Influenced by Different

Doses of Biogenic Silica and Time of Application

Treatments

Plant

Populat-

ion / m2

Number

of

Tillers/

m2

Number of

Effective

Tillers/ m2

Number

of Grains/

Panicle

Test

Weight

(g)

Panicle

Length

(cm)

Experimental Set I:

Application of different

Biogenic Silica doses at

the time of

transplantation

250 kg/ha 116 251 230 144 19.86 22.36

375 kg/ha 117 257 237 152 20.43 23.06

500 kg/ha 117 261 241 155 21.23 23.82

SEm± 2.29 2.08 2.25 1.24 0.24 0.31

CD at 5% NS 6.24 6.74 3.72 0.71 0.93


Separate application of

Biogenic Silica at 500

kg/ha dose at different

stages of crop life cycle

At vegeta-

tive

growth

stage

115 258 234 147 20.55 23.68

At full

bloom

stage

119 279 256 163 21.28 24.41

At grain

develop-

ment stage

116 236 218 142 19.69 21.61

SEm± 2.29 3.60 2.25 1.24 0.24 0.31

CD at 5% NS 10.81 6.47 3.72 0.71 0.93



Table VI: Effect of Biogenic Silica Application on Yield of Rice as Influenced by Different Doses of

Biogenic Silica and Time of Application

Treatments Grain Yield (q/ha) Straw Yield (q/ha)

Experimental Set I:

Application of different Biogenic Silica

doses at the time of transplantation

250 kg/ha 39.59 80.48

375 kg/ha 42.06 86.92

500 kg/ha 43.58 90.37

SEm± 1.02 1.92

CD at 5% 3.08 5.77


Separate application of Biogenic

Silica at 500 kg/ha dose at different

stages of crop life cycle

At vegetative growth stage 41.09 86.68

At full bloom stage 45.74 92.49

At grain development stage 38.40 78.59

SEm± 1.02 1.92

CD at 5% 3.08 5.77

Figure 1: Percentage Increase / Decrease in the Concentration of Soil Nitrogen and Potassium in Treatments as

Compared to Initial Concentration (PS: pre sowing; VG; vegetative stage; FB: full bloom stage; GD: grain

development stage)

-0.38

1.08 0.56

0.21

2

-1.03

0.81

1.41

2.02 2.09

3.2

-1.04-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

PS-250 PS-375 PS-500 VG-500 FB-500 GD-500

%In

crea

se/D

ecre

ase

in C

once

ntr

atio

n

Nitrogen

Potassium



.

Figure 2: Percentage Increase / Decrease in the Concentration of Soil Phosphorus in Treatments as Compared to

Initial Concentration (PS: pre sowing; VG; vegetative stage; FB: full bloom stage; GD: grain development

stage)

38.72

40.72

42.17

41.93

42.25

37.43

37

38

39

40

41

42

43

PS-250 PS-375 PS-500 VG-500 FB-500 GD-500

%In

crea

se/D

ecre

ase

in C

once

ntr

atio

n o

f P





EFFECTS OF TERMITES ON CONSTRUCTION TIMBERS IN

IBARAPA EAST LOCAL GOVERNMENT AREA OF OYO

STATE IN NIGERIA

1Olaniyan, A

Building Technology Department, 1The Polytechnic Ibadan,

P. M. B. 22, U.I Post Office,

Ibadan, Oyo State, Nigeria.

2Ibikunle, O. A,

3Olayanju, A. B,

4Olagoke, B. E and

5Olawoore, W. A

2,3,4&5Civil Engineering Department,

The Ibarapa Polytechnic, Eruwa.

P. M. B. 1015, Eruwa,

Oyo State, Nigeria

ABSTRACT: Termites cause billions of dollars in damage each year. They primarily feed on wood, but also

damage paper, books, insulation, and even swimming pool liners and filtration systems. Termites can injure

living trees and shrubs. Besides the monetary impact, thousands of winged termites emerging inside one's home

are an emotionally trying experience - not to mention the thought of termites silently feasting on one's largest

investment.

Termites are able to assess wood sizes using vibrating signals, although the exact mechanism behind this

assessment ability is not known. However, they are also dependent on the material characteristics of the block,

such as mass, density and internal damping. Hence the termite effects on timbers used for construction in

Ibarapa East Local Governments, area is hereby studied.

Buildings were surveyed in different locations and several observations were made on timbers affected by

termite and different ways attempted in preventing the devastating impact of termites on building timbers were

application of insecticides, locust beans water, the plant of local tree named pakan pakan. Analysis of the results

shown that more than eighty-three percent buildings selected for study seriously devastated by termites in the

studied area. Moreover, 21.43% buildings been abandoned, 32.14% had collapsed and the remaining 46.43%

were still habitable for owners.

Conclusively, termite attack is the most common cause of insect attack on timber in the studied area and its

damage could be extensive and can be expensive to repair. However, simple precautions like Timber treatment,

Avoidance of contact of susceptible timber with ground by using termite resistant concrete steel or DPC, Use of

timber that is naturally resistant to termites such as Syncarpia glomulifera (Turpentine Tree), Callitris

glaucophylla (White Cypress), Ayin or one of the Sequoias before construction could reduce the risk, and

finally, maintenance routine that would include pruning trees back from buildings, and checking for galleries on

post timber decay should be employed.

Key words: Termite, building, wooden, filtration, timbers, pakan-pakan.

INTRODUCTION

Over many years, sandcrete blocks, bricks, mud, cements, raffia palm and concrete have been used as

construction materials in building structure. However, the use of wood can not be avoided for its complex

varieties of purpose such as roofs, ceilings, furniture, cabinet, doors and windows. Though the cost of wood is

very high its beauty and durability is a priceless thing. Its beauty though may just end up devastated due to

termite‘s invasion. These termites are extremely destructives because they tunnel their way into wooden

structures, into which they burrow to obtain food. Given enough time, they will feed on the wood until nothing

is left but a shell, which cause collapse or damage of the wooden members of the building. Today, termite

proofing and control have been widely used. This is done by injecting the solution by the use of soil injector at

300mm interval along the perimeter of the building and under the slab, some slab injector is used. Treatment is

done until the queen termite is exterminated.

Small, herbivous termite insect are known to loose substrate borne vibration signals in gathering information

about their environment and in communication with members of their own species. Substrate born-vibration

http://en.wikipedia.org/wiki/Timber_treatment

http://en.wikipedia.org/wiki/Syncarpia_glomulifera

EFFECTS OF TERMITES ON CONSTRUCTION TIMBERS IN IBARAPA EAST LOCAL


signal are well suited for such purposes in small insect owing to biophysical constrain such as the sizes of the

insect and its receptor organ and the environment in which they live.

Termite, being small, herbivous and social insect, are known to employed vibration signal alarm, for example

are well reported recently, it was discovered that dry wood termite in the genius cryptotermes use vibration to

asses wood food volume with the suggestion that the frequency response of the wood (i.e. from the elastic by-

product of feeding on the block) might be used by termite as the assessment method. However, this conjecture

remained to be explicitly proofed. How termites use this signal is not entirely clear and other factor such as

wood block mass may also be important.

The vibratory characteristic of any structure are strongly dependent on its material properties. Two important

material properties that influence structural vibration are the velocity of longitudinal vibration (speed of sound)

and the amount of internal loss (damping) in the material. Wood, the food dry wood termites, displays highly

variable materials properties and, for example, may be found as part of live tree or as a dead log on the ground

and is often located in a varieties of environment and / or embedded in soil all these factors might alter the

effective vibratory properties and increase the range of material properties in termite encounter. Termites forage

in all of this diverse situations their ability to asses wood as a food source ought to have evolve to cope with

these complexities the decision to eat a particular pieces of wood could be informed by the vibrational signals

they receive, which in turn depend on the material properties of the food source.

If the cryptotermes termites do use the frequency response of the wood as the primary assessment method, then

perhaps they can be fooled by altering the material properties of a wooden block so as to manipulate the

frequency response. It is possible to construct a composite block that are present in a wooden surface to termites

with different material behind, thus altering the vibratory response and other characteristics of the composite

structures, compared to a block of pure wood. The different material could include one with low damping and

high speed of sound and other with high damping and low speed of sound, relative to wood, and thereby identify

which (if any ) of these factor are employed by the termite.

Aim and objectives of study.

The aim of this research is to assess the termite effect on timbers and extent of damages on building components

in studied area and objectives of study are as follows:

To determine the effect of termite on construction timbers

To know the type of termite that mostly affects the timbers in this area.

To determine the way termite assess and damage the wood

To know the particular area where termite affects the timbers in Ibarapa East Local Government

Area.

This study only tells about the effect of timber in different locations in Ibarapa East Local Government which

includes Lanlate and Eruwa as major towns with surrounded by villages like Maya, Akete,. Aderonmu,

Dagilegbo, Okolo.

Timbers widely used for various building constructions in Ibarapa East Local Government have shown

significant presences of termites owing to their ‗galleries‘ made of soil between their nest and their food source,

these galleries from the soil to the posts, beams and roofs of the buildings are the sign of termites attack on

timbers of buildings in area.

Timber.

Timber is a material used for carpentry and joinery work. Carpentry mainly concerns with constructional works

such as roofs, floors, partitions etc. it is the wood obtained from extrogenous trees by cutting these trees after

their full growth. Timber being one of the most important materials in civil engineering works and other

technical related work courses of a country. The timber is mainly of two types, namely soft wood and hard

wood.

Soft wood The soft wood is obtained from tree having needle shaped leaves or carnifalers, the various soft woods are kail,

pine, deodar, chir, walnut, semal and sprue. It is widely used for building constructions; the soft wood has the

following characteristics: It is light in colour and weight, it has straight fiber and fine texture, it has good tensile

resistance but is weak across the fibers, it is readily catches fire because it is a resinous wood and also easy to be

worked on.

Hard wood

The hard wood is obtained from tree having broad leaves or deciduous. The various hard woods are sail, teak,

mahogany shishan, oak, beack, ash, bamboo, neon, mango etc. it is widely used for door, furniture, joinery etc.

the hard wood have the following characteristics: It is dark in colour and heavier in weight, its fibres are quite



close and compact, it is non resinous wood, it is both good tensile as well as shears resistance and it is difficult

to work with.

Seasoning of timbers which is the process of drying timber or removing moisture content or sap, present in a

freshly fell tree, under controlled condition could be carried out by the following common methods:

Natural seasoning or air seasoning: The tree after felling is converted into logs, plank or batten. These are

stacked in dry places about 300mm above the floor level with longitudinal and cross pieces arranged one upon

the other. While stacking should be ensure that there is a space between them for free circulation of air all

around each pieces in order to prevent the effect of moisture on the wood from the bottom. A layer of Ander ash

or sand is spread on the level platform before stacking the wood. These stack woods are turned upside down

periodically in order to accelerate the rate of dry the wood got dried due to the circulation of free air. This

method is simple and cheap but very slow. Artificial seasoning: This is the quickest method of seasoning

woods and is commonly used. It keeps the moisture content under control. The processes are carried out in a

chamber under a control temperature and humidity condition with proper air circulation and ventilation system.

Usually, steam is used for this purpose. The seasoning is started at a comparatively lower temperature and high

humidity, the condition are changed as the timber dries. At the end of the seasoning, the air is fairly hot and

humidity is low. The required humidity level is maintained to avoid warping and cracking of the wood, the

drying of the wood at a uniform air is well maintained by the circulating air. The ventilation is provided to avoid

over heating and excessive humidity. Before removing the wood, the kiln is allowed to cool the temperature

inside the kiln is within 15oc and 20

oc of outside temperature.

Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order

Isoptera (see taxonomy below), but are now accepted as the epifamily Termitoidae, of the cockroach order

Blattaria. While termites are commonly known, especially in Australia, as "white ants," they are not closely

related to true ants. Like ants, some bees, and wasps which are all placed in the separate order Hymenoptera-

termites divide labour among castes, produce overlapping generations and take care of young collectively.

Termites mostly feed on dead plant material, generally in the form of wood, leaf litter, soil, or animal dung, and

about 10 percent of the estimated 4,000 species (about 2,600 taxonomically known) are economically significant

as pests that can cause serious structural damage to buildings, crops or plantation forests. Termites are major

detritivores, particularly in the subtropical and tropical regions, and their recycling of wood and other plant

matter is of considerable ecological importance. As eusocial insects, termites live in colonies that, at maturity,

number from several hundred to several million individuals. Colonies use decentralised, self-organised systems

of activity guided by swarm intelligence to exploit food sources and environments that could not be available to

any single insect acting alone. A typical colony contains nymphs (semi-mature young), workers, soldiers, and

reproductive individuals of both genders, sometimes containing several egg-laying queens.

Social organization Reproductives

Preserved specimen of fertile termite queen, showing distended abdomen. The rest of its body is the same size

as that of a worker. A female that has flown, mated, and is producing eggs is called a "queen." Similarly, a male

that has flown, mated, and in proximity to a queen is termed a "king." Research using genetic techniques to

determine relatedness of colony members is showing that the idea that colonies are only ever headed by a

monogamous royal pair is wrong. Multiple pairs of reproductives within a colony are not uncommon. In the

families Rhinotermitidae and Termitidae, and possibly others, sperm competition does not seem to occur (male

genitalia are very simple and the sperm are anucleate), suggesting that only one male (king) generally mates

within the colony. At maturity, a primary queen has a great capacity to lay eggs. In physogastric species, the

queen adds an extra set of ovaries with each molt, resulting in a greatly distended abdomen and increased

fecundity, often reported to reach a production of more than 2,000 eggs a day. The distended abdomen increases

the queen's body length to several times more than before mating and reduces her ability to move freely, though

attendant workers provide assistance. The queen is widely believed to be a primary source of pheromones useful

in colony integration, and these are thought to be spread through shared feeding (trophallaxis). The king grows

only slightly larger after initial mating and continues to mate with the queen for life. This is very different from

ant colonies, in which a queen mates once with the male(s) and stores the gametes for life, and the male ants die

shortly after mating. The winged (or

"alate'") caste, also referred to as the reproductive caste, are generally the only termites with well-developed

eyes, although workers of some harvesting species do have well-developed compound eyes, and, in other

species, soldiers with eyes occasionally appear. Termites on the path to becoming alates (going through

incomplete metamorphosis) form a subcaste in certain species of termites, functioning as workers

("pseudergates") and also as potential supplementary reproductives. Supplementaries have the ability to replace

a dead primary reproductive and, at least in some species, several are recruited once a primary queen is lost. In

areas with a distinct dry season, the alates leave the nest in large swarms after the first good soaking rain of the

rainy season. In other regions, flights may occur throughout the year, or more commonly, in the spring and

http://en.wikipedia.org/wiki/Eusociality

http://en.wikipedia.org/wiki/Insect

http://en.wikipedia.org/wiki/Taxonomy

http://en.wikipedia.org/wiki/Order_%28biology%29

http://en.wikipedia.org/wiki/Termite#Taxonomy.2C_evolution_and_systematics

http://en.wikipedia.org/wiki/Epifamily

http://en.wikipedia.org/wiki/Blattaria

http://en.wikipedia.org/wiki/Australia

http://en.wikipedia.org/wiki/Ant

http://en.wikipedia.org/wiki/Bee

http://en.wikipedia.org/wiki/Wasp

http://en.wikipedia.org/wiki/Hymenoptera

http://en.wikipedia.org/wiki/Detritus

http://en.wikipedia.org/wiki/Plant_litter

http://en.wikipedia.org/wiki/Detritivore

http://en.wikipedia.org/wiki/Subtropics

http://en.wikipedia.org/wiki/Tropics

http://en.wikipedia.org/wiki/Eusociality

http://en.wikipedia.org/wiki/Self-organization

http://en.wikipedia.org/wiki/Swarm_intelligence

http://en.wikipedia.org/wiki/Monogamous

http://en.wikipedia.org/wiki/Sperm_competition

http://en.wikipedia.org/wiki/Genitalia

http://en.wikipedia.org/w/index.php?title=Physogastric&action=edit&redlink=1

http://en.wikipedia.org/wiki/Ecdysis

http://en.wikipedia.org/wiki/Abdomen

http://en.wikipedia.org/wiki/Fecundity

http://en.wikipedia.org/wiki/Pheromone

http://en.wikipedia.org/wiki/Trophallaxis

http://en.wikipedia.org/wiki/Gametes

http://en.wikipedia.org/wiki/Incomplete_metamorphosis

http://en.wikipedia.org/wiki/Dry_season



autumn. Termites are relatively poor fliers and are readily blown downwind in wind speeds of less than 2 km/h,

shedding their wings soon after landing at an acceptable site, where they mate and attempt to form a nest in

damp timber or earth.

Worker termite

Worker termites undertake the labors of foraging, food storage, brood and nest maintenance, and some defense

duties in certain species. Workers are the main caste in the colony for the digestion of cellulose in food and are

the most likely to be found in infested wood. This is achieved in one of two ways. In all termite families except

the Termitidae, there are flagellate protists in the gut that assist in cellulose digestion. However, in the

Termitidae, which account for approximately 60 percent of all termite species, the flagellates have been lost and

this digestive role is taken up, in part, by a consortium of prokaryotic organisms. This simple story, which has

been in entomology textbooks for decades, is complicated by the finding that all studied termites can produce

their own cellulase enzymes, and therefore can digest wood in the absence of their symbiotic microbes. Our

knowledge of the relationships between the microbial and termite parts of their digestion is still rudimentary.

What is true in all termite species, however, is that the workers feed the other members of the colony with

substances derived from the digestion of plant material, either from the mouth or anus. This process of feeding

of one colony member by another is known as trophallaxis and is one of the keys to the success of the group. It

frees the parents from feeding all but the first generation of offspring, allowing for the group to grow much

larger and ensuring that the necessary gut symbionts are transferred from one generation to another. Some

termite species do not have a true worker caste, instead relying on nymphs that perform the same work without

moulting into a separate caste.

Soldiers The

soldier caste has anatomical and behavioural specializations, providing strength and armour which are primarily

useful against ant attack. The proportion of soldiers within a colony varies both within and among species.

Many soldiers have jaws so enlarged that they cannot feed themselves, but instead, like juveniles, are fed by

workers. The pantropical subfamily Nasutitermitinae have soldiers with the ability to exude noxious liquids

through either a horn-like nozzle (nasus) or simple hole in the head (fontanelle). Fontanelles which exude

defensive secretions are also a feature of the family Rhinotermitidae. Many species are readily identified using

the characteristics of the soldiers' heads, mandibles, or nasus. Among the drywood termites, a soldier's globular

("phragmotic") head can be used to block their narrow tunnels. Termite soldiers are usually blind, but in some

families, soldiers developing from the reproductive line may have at least partly functional eyes.

Figure 1. A Nasute Soldier

A nasute: The specialization of the soldier caste is principally a defense against predation by ants. The wide

range of jaw types and phragmotic heads provides methods that effectively block narrow termite tunnels against

ant entry. A tunnel-blocking soldier can rebuff attacks from many ants. Usually more soldiers stand by behind

the initial soldier so once the first one falls another soldier will take the place. In cases where the intrusion is

coming from a breach that is larger than the soldier's head, defense requires special formations where soldiers

form a phalanx-like formation around the breach and blindly bite at intruders or shoot toxic glue from the nasus.

This formation involves self-sacrifice because once the workers have repaired the breach during fighting, no

return is provided, thus leading to the death of all defenders. Another form of self-sacrifice is performed by

Southeast Asian tar-baby termites (Globitermes sulphureus). The soldiers of this species commit suicide by

autothysis—rupturing a large gland just beneath the surface of their cuticle. The thick yellow fluid in the gland

becomes very sticky on contact with the air, entangling ants or other insects who are trying to invade the nest.

Termites undergo incomplete metamorphosis, with their freshly hatched young taking the form of tiny termites

that grow without significant morphological changes (other than wings and soldier specializations). Some

http://en.wikipedia.org/wiki/Cellulose

http://en.wikipedia.org/wiki/Flagellate

http://en.wikipedia.org/wiki/Protist

http://en.wikipedia.org/wiki/Prokaryotic

http://en.wikipedia.org/wiki/Entomology

http://en.wikipedia.org/wiki/Cellulase

http://en.wikipedia.org/wiki/Enzyme

http://en.wikipedia.org/wiki/Mouth

http://en.wikipedia.org/wiki/Anus

http://en.wikipedia.org/wiki/Trophallaxis

http://en.wikipedia.org/wiki/Fontanelle

http://en.wikipedia.org/wiki/Mandible_%28insect_mouthpart%29

http://en.wikipedia.org/wiki/Phalanx_formation

http://en.wikipedia.org/wiki/Globitermes_sulphureus

http://en.wikipedia.org/wiki/Autothysis

http://en.wikipedia.org/wiki/Metamorphosis_%28biology%29



species of termite have dimorphic soldiers (up to three times the size of smaller soldiers). Though their value is

unknown, speculation is that they may function as an elite class that defends only the inner tunnels of the

mound. Evidence for this is that, even when provoked, these large soldiers do not defend themselves but retreat

deeper into the mound. On the other hand, dimorphic soldiers are common in some Australian species of

Schedorhinotermes that neither build mounds nor appear to maintain complex nest structures. Some termite taxa

are without soldiers; perhaps the best known of these are the Apicotermitinae.

Diet Termites are

generally grouped according to their feeding behaviour. Thus, the commonly used general groupings are

subterranean, soil-feeding, drywood, dampwood, and grass-eating. Of these, subterraneans and drywoods are

primarily responsible for damage to human-made structures.

All termites eat cellulose in its various forms as plant fibre. Cellulose is a rich energy source (as demonstrated

by the amount of energy released when wood is burned), but remains difficult to digest. Termites rely primarily

upon symbiotic protozoa (metamonads) such as Trichonympha, and other microbes in their gut to digest the

cellulose for them and absorb the end products for their own use. Gut protozoa, such as Trichonympha, in turn

rely on symbiotic bacteria embedded on their surfaces to produce some of the necessary digestive enzymes. This

relationship is one of the finest examples of mutualism among animals. Most so-called higher termites,

especially in the Family Termitidae, can produce their own cellulase enzymes. However, they still retain a rich

gut fauna and primarily rely upon the bacteria. Owing to closely related bacterial species, it is strongly presumed

that the termites' gut flora are descended from the gut flora of the ancestral wood-eating cockroaches, like those

of the genus Cryptocercus. Some species of termite practice fungiculture.

They maintain a ―garden‖ of specialized fungi of genus Termitomyces, which are nourished by the excrement of

the insects. When the fungi are eaten, their spores pass undamaged through the intestines of the termites to

complete the cycle by germinating in the fresh faecal pellets. They are also well known for eating smaller

insects in a last resort environment.

Nests Termite workers

build and maintain nests to house their colony. These are elaborate structures made using a combination of soil,

mud, chewed wood/cellulose, saliva, and feces. A nest has many functions such as to provide a protected living

space and to collect water through condensation. There are reproductive chambers and some species even

maintain fungal gardens that are fed on collected plant matter, providing a nutritious mycelium on which the

colony then feeds (see "Diet," above). Nests are punctuated by a maze of tunnel-like galleries that provide air

conditioning and control the CO2/O2 balance, as well as allow the termites to move through the nest.

Nests are commonly built underground, in large pieces of timber, inside fallen trees or atop living trees. Some

species build nests aboveground, and they can develop into mounds. Homeowners need to be careful of tree

stumps that have not been dug up. These are prime candidates for termite nests and being close to homes,

termites usually end up destroying the siding and sometimes even wooden beams.

Mounds

Mounds (also known as "termitaria") occur when an aboveground nest grows beyond its initially concealing

surface. They are commonly called ―anthills‖ in Africa and Australia, despite the technical incorrectness of that

name. In tropical savannas the mounds may be very large, with an

extreme of 9 metres (30 ft) high in the case of large conical mounds constructed by some Macrotermes species

in well-wooded areas in Africa. Two to three metres, however, would be typical for the largest mounds in most

savannas. The shape ranges from somewhat amorphous domes or cones usually covered in grass and/or woody

shrubs, to sculptured hard earth mounds, or a mixture of the two. Despite the irregular mound shapes, the

different species in an area can usually be identified by simply looking at the mounds.

Shelter tubes

Nasutiterminae shelter tubes on a tree trunk provide cover for the trail from nest to forest floor.Termites are

weak and relatively fragile insects that need to stay moist to survive. They can be overpowered by ants and other

predators when exposed. They avoid these perils by covering their trails with tubing made of feces, plant matter,

and soil. Thus the termites can remain hidden and wall out unfavourable environmental conditions. Sometimes

these shelter tubes will extend for many metres, such as up the outside of a tree reaching from the soil to dead

branches.

To a subterranean termite any breach of their tunnels or nest is a cause for alarm. When the Formosan

subterranean termite (Coptotermes formosanus) and the Eastern subterranean termite (Reticulitermes flavipes)

detect a potential breach, the soldiers will usually bang their heads apparently to attract other soldiers for

defence and recruit additional workers to repair any breach.

http://en.wikipedia.org/wiki/Dimorphic

http://en.wikipedia.org/wiki/Cellulose

http://en.wikipedia.org/wiki/Metamonad

http://en.wikipedia.org/wiki/Trichonympha

http://en.wikipedia.org/wiki/Microbe

http://en.wikipedia.org/wiki/Trichonympha

http://en.wikipedia.org/wiki/Bacteria

http://en.wikipedia.org/wiki/Digestive_enzyme

http://en.wikipedia.org/wiki/Mutualism_%28biology%29

http://en.wikipedia.org/wiki/Family

http://en.wikipedia.org/wiki/Cellulase

http://en.wikipedia.org/wiki/Gut_flora

http://en.wikipedia.org/wiki/Cockroach

http://en.wikipedia.org/wiki/Cryptocercus

http://en.wikipedia.org/wiki/Fungiculture

http://en.wikipedia.org/wiki/Termitomyces

http://en.wikipedia.org/wiki/Mycelium

http://en.wikipedia.org/wiki/Tropical_savanna

http://en.wikipedia.org/wiki/Savanna

http://en.wikipedia.org/wiki/Formosan_subterranean_termite



http://en.wikipedia.org/wiki/Eastern_subterranean_termite



RESEARCH METHODOLOGY Description of the study area

Ibarapa East Local Government Area is one of the thirty three local governments of Oyo state, Nigeria. Land

area of eight hundred and thirty eight (838) square kilometers with total population of about one hundred and

eighteen thousand two hundred and twenty six (118,226) as at the 2006 national census, (NPC). Its local

government head quarter is situated in a town named Eruwa.

Research Methodology

This focuses on the research method adopted for the collection of data such as administering questionnaire,

direct oral interview and personal observations. Simple random sampling technique was also employed and the

last stage involved data analysis using mainly descriptive statistics method.

Study Population

The population under study is the number of buildings sampled suffering from the impact of termites in Ibarapa

east local government.

Method of Data Collection

The questionnaires were administered to the respondents concerned in addition to interviews and personal

observations which altogether formed research instrumentation. The results obtained through these then formed

the data to be analyzed. The close ended questionnaires were designed to collect data from the study

areas in Ibarapa east local government and it was constructed in such a way that it brings out relevant

information needed for the work at hand.

RESULTS AND DISCUSSIONS About one hundred and forty buildings constructed of various materials were surveyed and selected for research

work throughout Ibarapa East Local Government. Percentage of termites‘ effects based on materials and

methods used for construction were collated and represented in the table 1 and figure 2 below. Based on

materials and methods used, twenty houses were selected in each case which revealed that hundred percent

(100%) of houses based on the following were greatly affected by termites: buildings constructed with mud,

building constructed with grass and wood and the one made of grass, mud and wood. Also, about sixty percent

(60%) houses made of damp proof course with either brick or block was severely attacked as well and buildings

constructed of brick and block walls without damp proof course were ninety (90%) and eighty (80%) percent

respectively. However, most of planks used for various constructions like ceilings, roof trusses, door frames,

windows, and window frames of buildings were either made from thick, neem, ayin, iroko timbers etc.

Moreover, table 2 and figure 3 were used to show the building stages in the location. About twenty-one (21%)

percent of the houses were abandoned, thirty-two (22%) percent collapsed while about forty-seven (47%)

percent were still habitable by their owners.

Termite damages were rampant in the studied areas was found to affect more than eighty-three (83%) percent of

the selected buildings chose for study in Ibarapa East Local Government Area

Termite attack often started from the ground or from tree branches touching the building in addition to dead

wood, tree stumps, wood stack and nearness to the forested area which in turn enhance the likelihood of said

attack.

In addition, the termites, was discovered looking for their own food, and create nest under the ground and create

a tunnel to a damp area of the building. They create the tunnel from the underground through the face of the

wall to the timber part of the building such as window, roof, window frame, doors, and door lining and eat the

wood and later destroyed the wooden member. They even create their mounds to the roof of the structure so that

it will be easy for them to asses the nearest wood of the structure.



Table 1 Table Showing the Effect of Termites in Ibarapa East Local Government Area.

S/N Type of Building Members affected Frequency No. attack by

termites

% of

Occurrence

1 Buildings constructed

with mud.

Walls, windows,

roofs.

20 20 17.09

2 Buildings constructed of

damp proof course and

brick walls.

Window frames, roof

trusses.

20 12 10.25


damp proof course and

block walls.

Window frames, roof

trusses.

20 11 9.40


brick walls only.

Ceilings, roof trusses,

door frames,

windows, window

frames.

20 18 15.38


block walls only.

Ceilings, roof trusses,

door frames,

windows, window

frames.

20 16 13.68

6 Building constructed with

grass and wood.

Wood planks and

grass.

20 20 17.09

7 Building constructed with

grass, mud and wood.

Mud walls, timbers

and grass.

20 20 17.09

Total 140 117 100

0

2

4

6

8

10

12

14

16

18

Mud

Buildings

Buildings

with d.p.c

and brick

wall.

Buildings

with d.p.c

and block

wall.

Buildings

with brick

walls only.

Buildings

with block

walls only.

Building

with grass

and wood.

Building

with grass

wood and

mud

Series1

Figure 2. Bar Chart Showing Various Building Affected By Termite in Ibarapa East Local Government

Area.

Table 2. Numbers and Percentages of Buildings Affected by Termites in Ibarapa East Local

Governments Area.

Buildings Number Percentage (%)

Abandoned 30 21.43

Collapsed 45 32.14

Living 65 46.43

Total 140 100



Abandoned

Collapsed

Living

Figure 3. Pie Chart Showing the Numbers and Percentages of Buildings Affected by Termites in Ibarapa

East Local Governments Area.

CONCLUSION

Timber decay is caused by a biological attack on the wood by certain species of fungi. The fungal spores lie

dormant in the timber for years until the right conditions present themselves. The conditions needed are

moisture or dampness and nutrients, with moisture being the critical component. If moisture is not present in

timber, then the fungi will remain dormant, even when the nutrients they require are abundant. Termite attack is

the most common cause of insect attack on timber in the studied area. A common misconception is that a termite

is an ant. It is in fact a type of cockroach. Termite damage can be extensive and can

be expensive to repair. Simple precaution before construction can reduce the risk, and maintenance routine

should include pruning trees back from buildings, and checking for galleries on post.

Buildings should regularly be inspected so as to destroy the colony of termites that may by present at all time.

Treatment with solegnum, creosote, locust beans water, appear to be effective in preventing the destructive

impact of termite in the area. Furthermore, once termites invasion is discovered in a building,

corrective control measure should be applied so as to cub the menace.

RECOMMENDATIONS Considering the study findings, the following steps are hereby recommended as preventive and corrective

measures in combating the harmful impact of termites in Ibarapa East Local Government Area of Oyo State in

Nigeria:

Timber treatment: Treatment with creosote appears to be effective, and the results of using different

chemicals should be monitored and the cost-effectiveness of treatment by the Forest Research Centre and

private firms compared.

When termite have already penetrated a building, the first action is usually to destroy the colony with

insecticides before removing the termites‘ means of access and fixing the problems that encouraged them in the

first place.

Avoid contact of susceptible timber with ground by using termite resistant concrete steel or masonry

foundation with appropriate barriers (DPC) since findings show that building made of (DPC) were less prone to

attack

The intent of termite barriers (whether physical, poisoned soil, or some of the new poisoned

plastics) should be provided to prevent the termites from gaining unseen access to structures.

Use of timber that is naturally resistant to termites such as Syncarpia glomulifera (Turpentine Tree),

Callitris glaucophylla (White Cypress), Ayin or one of the Sequoias. However, there is no tree species whose

every individual tree yields only timbers that are immune to termite damage, so that even with well-known

termite-resistant timber types, there will occasionally be pieces that are attacked. No species of tree produces

timber that is completely immune to damage from every species of termite; some individual pieces of wood may

be attacked.

http://en.wikipedia.org/wiki/Timber_treatment

http://en.wikipedia.org/wiki/Syncarpia_glomulifera



REFERENCES [1]. Bordereau, C. Robert, A. Van Tuyen, V. & Peppuy, A. (1997). Suicidal defensive behavior by frontal

gland dehiscence in Globitermes sulphureus Haviland soldiers (Isoptera)". Insectes Sociaux 44 (3): 289–

297.

[2]. D Lobeck, A.K. (1939). The evolution of fungus-growing termites and their mutualistic fungal

symbionts . Geomorphology: An introduction to the study of landscape. McGraw–Hill Book Company,

New York.

[3]. Encyclopædia Britannica Online Library Edition. Retrieved 19 November 2007

[4]. Engel, M.S. and K. Krishna (2004). Family-group names for termites (Isoptera)". American Museum

Novitates

[5]. Evans T.A, Lai J.C.S, Toledano E, McDowall L, Rakotonarivo S, Lenz M. Termites assess wood size

by using vibration signals.

[6]. Frank Owen and Ron Jones. (1994). Statistics, Longman Group United Kingdom limited

[7]. Inward, D., G. Beccaloni, and P. Eggleton. (2007). Death of an order: a comprehensive molecular

phylogenetic study confirms that termites are eusocial cockroaches. Biology Letters 3:331-335.

[8]. Kirchner W.H, Broecker I, Tautz J (1994). Vibrational alarm communication in the damp-wood

termite. Physiol. Entomol.

[9]. Khurmi, R.S and Gupta J. K (2004). A textbook of workshop technology.

[10]. Thapa, R S (1980) Termites of Sabah, Chin Chi Printing Works, Kota Kinabalu Grimaldi, D. and

Engel, M.S. (2005). Evolution of the Insects. Cambridge University Press. ISBN 0-521-82149-5.

[11]. Piper, Ross (2007). Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals,

Greenwood Press. .

http://en.wikipedia.org/wiki/Insectes_Sociaux

http://www.pnas.org/cgi/content/full/99/23/14887

http://www.pnas.org/cgi/content/full/99/23/14887

http://en.wikipedia.org/wiki/Michael_S._Engel

http://en.wikipedia.org/wiki/American_Museum_Novitates



http://en.wikipedia.org/wiki/Molecular_phylogeny



http://en.wikipedia.org/wiki/David_Grimaldi

http://en.wikipedia.org/wiki/Michael_S._Engel

http://en.wikipedia.org/wiki/Cambridge_University_Press

http://en.wikipedia.org/wiki/International_Standard_Book_Number

http://en.wikipedia.org/wiki/Special:BookSources/0-521-82149-5

http://en.wikipedia.org/wiki/Greenwood_Press_%28publisher%29





COMPLEX TRUSS ANALOGY USING PLASTIC AND

ELASTIC ANALYSIS

Ezeagu C.A. and Onunkwo R.C.

Department of Civil Engineering, Faculty of Engineering, Nnamdi Azikiwe University Awka.

ABSTRACT: The work exposes the fundamentals of the plastic and elastic theory of analysis and degree, in

order to sensitize its use. This work also compares the use of plastic method of structural analysis and elastic

method of structural analysis using a complex truss system being acted upon by mobile load as a case study.

This project disputes the common fact that only the elastic method of analysis is used to analyse mobile loads on

truss systems by introducing stipulated steps in plastic method of analysis for analyzing truss systems carrying

mobile loads. This project deals with the creation of a computer application that analyzes and designs structural

trusses. This program was created using the relatively new C# programming language. The project also

discusses various theoretical analysis techniques that can be implemented in developing a computer program.

The main theoretical methods used in this project are influence line analysis and plastic method of analysis of

mobile loads. The Reinforced concrete design is based on the EC3 code. The project solved the reactions on

each member using the influence line analysis for truss system by taking cognizance of the position of the

mobile load (at position x = 2a), at a particular time. The complex truss system was analysed using the plastic

method by unpinning the members of the truss system to form a frame and beams, for easy analysis. This project

designed the complex system using the current code for design regulation i.e. the Euro codes. The bracing

members were analysed and designed as a beam, fixed at the both ends and also at the middle. The results

obtained from the research of this work shows that the influence line analysis generates higher axial forces on

members which include; FC – D = W28a2

2hkN (compression), FC – I, and FC – J =

W2a a2+h2

hkN both in compression

and tension, then FC – J =W2a

3 kN (Tension) and

4W2a

3 kN (compression) and FJ – I =

3W2a2

h kN than the axial forces

generated using the plastic analysis method which also include; Jy =W3a+Mp

a(kN) (maximum compressive axial

force on vertical strut members), Ix =11Mp−2W3a−2W4h

2h kN tension and W4kN tension for both the lower chord

and the top chord respectively, when acted upon by the same magnitude of imposed live loads of W2kN. This is

so because the plastic method of analysis involves a lot of assumptions that makes it yet not advisable to be used

in the analyses of trusses carrying mobile loads.

keywords: Analysis, Elasticity, Load, Plasticity, and system.

Introduction: Engineering is a professional art of applying science to the efficient conversion of natural resources for the

benefit of man. Engineering therefore requires above all creative imagination to innovative useful application

for natural phenomenon (Kamath and Reddy, 2011) Basically there are two approaches to provide adequate strength of structures to support a given set of design

loads: Elastic Design and Plastic Design. Drift checks are also required in actual design practice, but the focus

of discussion herein will be limited to elastic and plastic method of designs on truss systems.

A truss is an assemblage of long, slender structural elements that are connected at their ends. Trusses find

substantial use in modern construction, for instance as towers, bridges, scaffolding, etc. In addition to their

practical importance as useful structures, truss elements have a dimensional simplicity that will help us extend

further the concepts of mechanics introduced in the modules dealing with uniaxial response.

In recent years, the engineers have done a lot of work to know the behaviour of structures, when stressed beyond

the elastic limit called plastic limit. This has led to the development of new theory popularly known as plastic

theory.

With the recent increase in the development of software programs, research engineers have developed computer

aided designs analogy using the available softwares on ground. Structures viz truss structures, concrete

structures e.t.c. are designed using these developed software designs. These computer aided designs include

using the methods of elastic and plastic analogy in the design of trusses.

Aim of the work: This work is aimed at determining the elastic and plastic analysis method of analysing

complex truss systems carrying mobile loads and comparing the both analysis.



www.ijlret.comǁ Volume 1 Issue 7ǁDecember 2015 ǁ PP 49-


Objectives of the study: The objectives of the work includes: 1. The comparison between the plastic and elastic methods of analysis and design on truss systems.

2. The elastic cum plastic deformations of structures under mobile loading condition.

3. The various methods of analysing the internal stresses that occur in a structure under external mobile loading eg.

Complex truss system.

4. The fundamental concepts of plastic analysis.

5. Understanding the basis of and limitations of plastic analysis approaches.

Literature Review: A truss is defined as a framework which gives a stable form capable of supporting

considerable external load over a large span with the components parts stressed primarily in axial tension or

compression (Ezeagu and Nwokoye, 2009). In a plane, a truss is composed of relatively slender members often

forming triangular configurations (Mau, 2002).

A truss is one of the major types of engineering structures which provides a practical and economical solution

for many engineering constructions, especially in the design of bridges and buildings that demand large spans

(Ustundag, 2005).

Trusses are statically determinate when all the bar forces can be determined from the equations of statics alone.

Otherwise the truss is statically indeterminate (Saouma, 2007).

Equilibrium is the most important concept of structural analysis. A structure that is initially at rest and remains

at rest when acted upon by applied loads is said to be in a state of equilibrium (Shanmugam and Narayanan,

2008). The resultant of the external loads on the body and the supporting forces or reactions is zero. Engineering

talk about two types of equilibrium; static and dynamic, although it can be argued that static equilibrium is a

special case of dynamic equilibrium. Static equilibrium exists if all parts of a structure can be considered

motionless. I.e. the structural parts, which are initially at rest, remain at rest when acted upon by a system of

force, which therefore suggested that the combined resultant effect of the system of forces shall be neither a

force nor a couple. Otherwise there will be a tendency for motion of the body.

When a structure is in equilibrium, every element or constituent part of it is also in equilibrium. This property is

made use of in developing the concept of the free body diagram for elements of a structure (Buick and Graham,

2003).Compatibility is concerned with deformation. If compatibility is assumed then geometric fit is implied.

That is, if a joint of structure moves, then the ends of the members connected to that joint move by the same

amount, consistent with the nature of the connection. A solution is compatible if the displacement at all points is

not a function of the path. Therefore, a displacement compatible solution involves the existence of a uniquely

defined displacement field (Buick and Graham, 2003).

Compatibility conditions require that the displacements and rotations be continuous throughout the structure and

compatible with the nature supports conditions. For example, at a fixed support this requires that displacement

and slope should be zero (Kharagpur, 2012).

In the case of a pin-jointed frame, compatibility means that the ends of the member at a joint undergo equal

translation. If the framework is rigidly joined, then, in addition to equal translation, the rotation of the ends of

the members meeting at a joint must be equal. According to Okoro (2004) in a project work titled the plastic

behaviour of structures (plastic analysis vs. elastic analysis) stated that the deformation of the structure set up

strains and related internal stresses within the elements. Stress is related to strain through the stress-strain laws,

which is a function of the type of material and the nature of the strain (Spencer, 1988). The best known stress-

strain law is that which defines linear elastic behaviour. In this case, stress is proportional to strain and the

constant of proportionality is Young‟s Modulus [E]. There are other stress-strain laws defining a wide range of

behaviour (like the plastic behaviour) but it should be appreciated that all stress-strain laws are approximates.

The major reason for interest in the assumption of linearity of structural behaviour is that it allows the use of

principle of superposition. This principle means that the displacement resulting from each of a number of forces

may be added to give the displacement resulting from the sum of the forces. Super-position also implies that the

forces corresponding to a number of displacements may be added to yield the force corresponding to the sum of

the displacements. The principle must not be used for analysis of non-linear structures or in the methods of

plastic theory.

Elastic materials are such that returns to its original state after undergoing an extension by an external force

once its elastic limit is not exceeded.

In the analysis of these two behaviour viz: elastic and plastic, there are differences in the mode or method of

analysis: In plastic analysis, the collapse load and load factor used in the design of such structure plays a vital

role. Once these two criteria are adequately catered for in the design, the structure would withstand any applied

force with visible deformations while in the elastic analysis, deflection limit is the major criteria for design. It is

design such that it could remain functional under a certain applied force once the deflection limit is not

exceeded.





The plastic method can be seen as a more rational method for design because all parts of the structure can be

given the same safety factor against collapse. In contrast for elastic methods the safety factor varies. Intrinsically

the plastic method of analysis is simpler than the elastic method because there is no need to satisfy elastic strain

compatibilty conditions. However calculations for instability and elastic deflections require careful

consideration when using the plastic method, but nevertheless it is very popular for the design of some

structures (e.g. beams and portal frames) (Martin and Purkiss, 2008).

Deflection becomes the governing factor of elastic analysis while the collapse load and load factor remains basis

of plastic analysis. If these criteria are strictly adhere to in the design of a structure using either of the analysis

method, then the success of the structure to a larger extent is certain. The plastic and elastic method of analysis

has various areas where they are applicable depending on the designer‟s choice and conservation in terms of

material. Since the plastic method of analysis is more economical in terms of material than the elastic method of

analysis.

The plastic method of analysis is used especially in the design of steel structure e.g. rigid frames, indeterminate

rigid frames. Since collapse load is the major criterion that which plastic method is based on, it is adequately

taken care of in the use of this design, thus design of ductile structure is plastic in nature so, plastic design is

basically needed.

It does not mean that elastic method is not also applicable in steel structure, but it is restricted to some extent.

Elastic method is used mainly in the design of reinforced concrete. The ability of a concrete structure to

maintain its shape or form under given deformation or deflection makes it elastic in nature as it would without

some degree of deformations and when exceeded, cracks makes this methods suitable for its use.

According to Okoro (2004) in a project work titled the plastic behaviour of structures (plastic analysis vs. elastic

analysis) stated that the traditional method of showing a typical engineering problem prior to the introduction of

the electronic digital computer was initially by a mathematician or an engineer who endeavoured to obtain a

solution based on strict scientific reasoning and with no regard to the resulting calculation (Litton, 1973).

However, this process was terminated by the introduction of the electronic computer, which provided the

opportunity for a fresh approach to the problem.

Theory of plasticity : The theory of plasticity is the branch of mechanics that deals with the calculation of

stresses and strains in a body, made of ductile material, permanently deformed by a set of applied forces

(Chakrabarty, 2006). The theory is based on certain experimental observations on the macroscopic behaviour of

metals in uniform states of combined stresses. The observed results are then idealized into a mathematical

formulation to describe the behaviour of metals under complex stresses.

Unlike elastic solids, in which the state of strain depends only on the final state of stress, the deformation that

occurs in a plastic solid is determined by the complete history of the loading. The plasticity problem is,

therefore, essentially incremental in nature, the final distortion of the solid being obtained as the sum total of the

incremental distortions following the strain path.

METHODOLOGY Development of elastic model Consider the bridge in Fig. 3.0. As the car moves across the bridge, the forces in

the truss members change with the position of the car and the maximum force in each member will be at a

different car location. The design of each member must be based on the maximum probable load each member

will experience.

Fig. 3.1: Mobile load on truss system





Therefore, the truss analysis for each member would involve determining the load position that causes the

greatest force or stress in each member.

If a structure is to be safely designed, members must be proportioned such that the maximum force produced by

dead and live loads is less than the available section capacity.

Structural analysis for variable loads consists of two steps:

a. Determining the positions of the loads at which the response function is maximum; and

b. Computing the maximum value of the response function.

Once an influence line is constructed;

Determine where to place live load on a structure to maximize the drawn response function; and

Evaluate the maximum magnitude of the response function based on the loading.

Consider a through type composite truss of 8 panels, each of length “a” and height “2h” as shown in Fig. 3.0. A

little consideration will show, that the truss consists of;

(i) A primary truss of panels each length of 2a and height 2h. (i.e. with members as CD,JI,CJ,CI and DJ)

(ii) 8 secondary trusses of 1 panel, each of length 2a and of height h as shown in Fig. 3.0

A little consideration will show, that some of the members in the second panel of the primary truss occur in the

primary truss only (e.g. CD, JI, CJ, and DI). Some members occur in both the primary as well as secondary

trusses (e.g. CL, LI, DL and LI). The influence lines for the members, which occur in the primary truss only,

will be given by the influence line for the corresponding member of the primary truss only. But the influence

lines for the members, which occur in both the primary and secondary trusses, may be drawn by joining the

points obtained by algebraically adding the ordinates of the influence lines for the corresponding members in the

primary as well as secondary truss. Cut a section on the member to be analyzed before analyzing.

The maximum force on any member due to a particular moving load is gotten by multiplying the moving load

with the area of the influence line diagram.

Development of plastic model : Consider the truss shown in Fig. 3.0 above, as the load moves on the truss it

distributes a udl on the top cord of the truss system.

Analysis of the complicated truss system as shown above using plastic method of analysis is rather not easy.

Therefore, for easier analysis, the members of the complicated truss system were unpinned into frames, beams

and bracing members. The top chord members and the struts (vertical members) were joined together to form a

continuous frame with uniformly distributed loading of W3kN. The frame is pinned at the end reactions and

fixed at the middle reactions. The internal members are analyzed as a continuous beam with uniformly

distributed loading of W6kN. The continuous beam is pinned at both ends and also at the middle. The lower cord

members were analyzed as a simple beam with uniformly distributed loading of W7kN, pinned at one end and

having roller support at the other end.

N.B – The ratio of the corresponding plastic section modulus (ZP) to the corresponding elastic section modulus

(ZE) of a particular section (both gotten from table) gives the Shape factor (S) of the section. The shape factor is

being multiplied by the factor of safety of the section (1.5) to give the section‟s load factor (LF). The Load factor

multiplied by the corresponding loading on each member gives the total load to be used for the plastic analysis

of the member.

Combined mechanism - The independent mechanisms are combined to determine the maximum Mp value

required to induce collapse with the minimum number of hinges. The shear forces at the various reactions were

obtained. For plastic analysis, the axial forces acting on each member are used for the design of the member and

it also shows whether the member is being acted upon by compression or tension forces.

Design of truss system : The top chord members are designed as I or H steel beam section. The vertical

members (struts) were designed as T or equal long angles back to back steel column section. The internal

bracing members were designed as L- steel bracing section. In the structural design of steel structures, reference

to standard code is essential. As EC3 will eventually replace BS 5950 as the new code of practice, it is necessary

to study and understand the concept of design methods in EC3.

Codes of practice provide detailed guidance and recommendations on design of structural elements. Buckling

resistance and shear resistance are two major elements of structural steel design. Therefore, provision for these

topics is covered in certain sections of the codes. The study on Eurocode 3 in this project will focus on the

subject of moment and shear design.

Design of Steel Beam According to EC3 The design of simply supported steel beam covers all the elements stated below. Sectional size chosen should

satisfy the criteria as stated below:





(i) Cross-sectional classification

(ii) Shear capacity

(iii) Moment capacity (Low shear or High shear)

(iv) Bearing capacity of web

a) Crushing resistance

b) Crippling resistance

c) Buckling resistance

(v) Deflection

Analysis, design and comparison works will follow subsequently. Beams and columns are designed for the

maximum moment and shear force obtained from computer software analysis. Checking on several elements,

such as shear capacity, moment capacity, bearing capacity, buckling capacity and deflection is carried out. Next,

analysis on the difference between the results using the two analysis (Elastic and Plastic) is done. Eventually,

comparison of the results will lead to recognizing the difference in design approach for each analysis.

Load distribution : Top Chord members – The top cord members carry a uniformly distributed loading of say

W3kN, which comprises of the total live load acting on the member and the member self weight (dead load).

Both multiplied by their factors of safety.

Vertical members (struts) – The vertical members carry a loading of say W8kN, which comprises of the total

loading coming from the top cord and the wind load multiplied by its factor of safety.

Bracing members – The bracing members are being acted upon by wind loads, their own self weight and------

multiplied by their various factors of safety which is denoted as W9kN.

The lower chord – The lower chord members are being acted upon by the live load and the self-weight of the

whole truss system multiplied by their various factors of safety, denoted in the project as W10kN.

Computer application of plastic and elastic analysis of truss system : For the purpose of this project, we are

going to analyze the complicated truss system using the C# programming language. The elastic and plastic

analysis of complicated truss system discussed in chapter four were encoded in the C# programming language

for easier analysis and to meet up with the growing trend of technology in the modern world.

C# (pronounced "see sharp") is a computerprogramming language. It is developed by Microsoft. It was created

to use all capacities of .NET platform. The first version was released in 2001. The most recent version is C# 5.0,

which was released in August 2012. C# is a modern language

TRUSS ANALYSIS

Member

ref.

Calculation Output

Design data: Span of truss (L) = 8a(m)

Height of truss = 2h(m)

Bracing length = 2 𝑕2 + 𝑎2 (m)

Span of each stanchion = 2a(m)

Let position of the load on any member at a particular time be = x

Bracing slope (Ө) = tan-1

2𝑕

2𝑎

Let the moving load longer than the span be W2 (kN/m)





Fig. 4.0: Truss system

4.1 INFLUENCE LINE ANALYSIS (Unit Load)

Fig. 4.1: Truss system with reations

Let the unit load be w(kN)

For Reactions

Ra = 𝐿 − 𝑥 𝑤

𝐿=

8𝑎 −4𝑎

8𝑎 × 1(kN)

Rg = 𝑥 𝑤

𝐿 =

4𝑎 ×1

8𝑎 (kN)

Influence line for force in member C-D

Fig. 4.2





Passing section 1 -1 cutting the member C – D as shown in fig. 3 above.

Member C – D occurs in the primary truss only, therefore the influence line

for this member may be drawn from the primary truss only.

Influence line for C-D = 𝐵𝑒𝑛𝑑𝑖𝑛𝑑 𝑀𝑜𝑚𝑒𝑛𝑡 𝑓𝑜𝑟 𝑖𝑛𝑓𝑙𝑢𝑛𝑐𝑒 𝑙𝑖𝑛𝑒 𝑓𝑜𝑟 𝐼

𝑉𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 𝐷−𝐼

Influence line (I.L) for Bending moment(B.M) at I is a triangle with

ordinate = 𝑥 𝐿− 𝑥

𝐿=

4𝑎 8𝑎 −4𝑎

8𝑎= 2𝑎(𝑘𝑁)

Therefore I.L for force in member C – D will also be a triangle with

ordinate = 2𝑎 ×1

2𝑕=

𝑎

𝑕(𝑘𝑁

Fig 4.3: Influence line diagram for member C – D

FC –D = W2 × Area of ADG

= 𝑊2 ×1

2× 8𝑎 ×

𝑎

𝑕 (compresion)

Influence line for force in member C-I

Member C – I occurs both in primary and secondary trusses. And as such

will be calculated as stated in chapter 3.

For Primary truss

Passing a section 2 – 2 cutting the member C – I as shown in fig. 4.5 below.

FC –D=𝑊28𝑎2

2𝑕

(compression)





Fig. 4.4

a) I.L for member C – I b/w AJ:𝑭𝑪𝑰 𝒔𝒊𝒏𝜽 = 𝑹𝑮

𝐹𝐶𝐼 =𝑅𝐺

sin 𝜃=𝑥𝑐𝑜𝑠𝑒𝑐 𝜃

𝐿

Where: x = 2a and L = 8a

𝐼. 𝐿𝐶𝐼 =2𝑎𝑐𝑜𝑠𝑒𝑐 𝜃

8𝑎=𝑐𝑜𝑠𝑒𝑐 𝜃

4 (𝑘𝑁)

b) I.L for member C – I b/w:𝑭𝑪𝑰 𝒔𝒊𝒏𝜽 = 𝑹𝑨

𝐹𝐶𝐼 =𝑅𝐴

sin 𝜃= 𝐿 − 𝑥

𝐿

sin𝜃


𝐹𝐶𝐼 = 8𝑎 − 4𝑎

8𝑎

sin𝜃=

1

2𝑐𝑜𝑠𝑒𝑐 𝜃(𝑘𝑁)

The I.L between the joints J and I will be a straight line joining the ordinate

under the joints J and I as shown below.

Fig. 4.5: Influence line diagram of the primary truss

𝐹𝐶−𝐼

=𝑐𝑜𝑠𝑒𝑐 𝜃

4 (𝑘𝑁)

(compression)

𝐹𝐶−𝐼

=1


(Tension)

For the secondary truss

i. I.L for force in member L – I:





Fig. 4.6: Influence line diagram of the secondary truss

The I.L for force in member L-I in the secondary truss will be given by the

I.L for bending moment at Q (the mid-point between points J and I)

opposite joint L divided by the vertical distance between the member L-I

and the opposite joint distance Q as shown in fig. 4.7b above.

I.L for B.M at Q is a triangle with ordinate =𝑎×𝑎

2𝑎=

𝑎

2

Therefore, I.L for member L.I =𝑎

2×

1

𝑍𝑄

=𝑎

2×

1𝑎𝑕

𝑎2+𝑕2 =

𝒂𝟐+𝒉𝟐

𝟐𝒉(kN) (Compression)

ii. I.L for force in member L – I:

The I.L for force in member C-L in the secondary truss will be given by the

I.L for bending moment at the opposite joint Y divided by /UY/ i.e the

vertical distance between the member CL and the opposite joint Y as shown

in fig. 4.4 above.

I.LL-I = a2+h2

2h(kN)

(Compression)

Fig. 4.7: Influence line diagram of the secondary truss

I.L for B.M at Y is a triangle with ordinate =𝑎×𝑎

2𝑎=

𝑎

2

Therefore, I.L for member C.L =𝑎

2×

1

𝑈𝑌

=𝑎

2×

1𝑎𝑕

𝑎2+𝑕2 =

𝒂𝟐+𝒉𝟐

𝟐𝒉(kN) (Tension)

Superposing influence lines C-I, L-I and C-L we will have;

I.LC.L = a2+h2

2h(kN)

(Tension)





Fig. 4.8: Influence line diagram of member C - I

FMax = W2 × Area of BEF

= 𝑊2 ×1

2× 4𝑎 ×

𝑎2+𝑕2

2𝑕 (compresion)

FMax = W2 × Area of FGI

= 𝑊2 ×1

2× 4𝑎 ×

𝑎2+𝑕2

2𝑕 (Tension)

Influence line for force in member D-J

Member D – J occurs both in primary and secondary trusses. And as such

will be calculated as stated in chapter 3.

For Primary truss

Passing a section 2 – 2 cutting the member D – J as shown in fig. 4.5 below.

Fig. 4.9

a) I.L for member D – J b/w /BC/:𝑰.𝑳𝑫𝑱 𝒔𝒊𝒏𝜽 = 𝑹𝑮

𝐼. 𝐿𝐷𝐽 =𝑅𝐺

sin𝜃=𝑥𝑐𝑜𝑠𝑒𝑐 𝜃

𝐿


FMax =𝑊2𝑎 𝑎

2+𝑕2

𝑕 (𝑘𝑁)

(compression)


2+𝑕2

𝑕 (𝑘𝑁)

(Tension)





𝐼. 𝐿𝐷𝐽 =2𝑎𝑐𝑜𝑠𝑒𝑐 𝜃

8𝑎=𝑐𝑜𝑠𝑒𝑐 𝜃

4 (𝑘𝑁)

𝐹𝐷−𝐽 =𝑐𝑜𝑠𝑒𝑐𝜃

4 (𝑘𝑁)

(Tension)

b) I.L for member C – I b/w /DF/:𝑰.𝑳𝑫𝑱 𝒔𝒊𝒏𝜽 = 𝑹𝑨

𝐼. 𝐿𝐷𝐽 =𝑅𝐴

sin𝜃= 𝐿 − 𝑥

𝐿

sin 𝜃


𝐹𝐶𝐼 = 8𝑎 − 4𝑎

8𝑎

sin𝜃=

1


The I.L between the joints C and D will be a straight line joining the

ordinate under the joints C and D as shown below.

Fig. 4.10: Influence line diagram of the primary truss

For the secondary truss

i. I.L for force in member L – J:

Member L-J has the same I.L diagram with member L-I

= 𝒂𝟐+𝒉𝟐

𝟐𝒉(kN)(compression)

ii. I.L for force in member D – L:

Member D-L has the same I.L diagram with member C-L

= 𝒂𝟐+𝒉𝟐

𝟐𝒉(kN)(Tension)

𝐹𝐷−𝐽

=𝑐𝑜𝑠𝑒𝑐 𝜃

2 (𝑘𝑁)

(compression)

I.LC.L = a2+h2

2h(kN)

(compression)

I.LC.L = a2+h2

2h(kN)

(Tension)

Superposing influence lines D - J, D - L and L - J we will have;





Fig. 4.11: Influence line diagram of member D -J

FMax = W2 × Area of FGI

= 𝑊2 ×1

2× 4𝑎 ×

𝑎2+𝑕2

2𝑕 (compresion)


= 𝑊2 ×1

2× 4𝑎 ×

𝑎2+𝑕2

2𝑕 (Tension)

Influence line for force in member C-J

Cutting the section 4 – 4 as shown below;

Fig. 4.12


2+𝑕2

𝑕 (𝑘𝑁)

(compression)


2+𝑕2

𝑕 (𝑘𝑁)

(Tension)

a) I.L for member C – J between /AJ/: Since the force RG acts upwards, force in member C-J will be acting

downwards thus causing tension.

I.LA-J = RG = 𝑥

𝐿

Where; x = 2a and L = 8a

I.LA-J=2𝑎

8𝑎=

1

4 (Tension)

b) I.L for member C – J between /IG/: Considering the left;

I.LA-J = RA = 𝐿−𝑥

𝐿


I.LA-J=4𝑎

8𝑎=

1

2 (compression)

I.LA-J=1

4

(Tension)

I.LA-J=1

2

(compression)





Fig. 4.13: Influence line diagram of member C - J

FMax = W2 × Area of FQG

= 𝑊2 ×1

2× 4𝑎 +

4𝑎

3 ×

1

2 (compression)


= 𝑊2 ×1

2× 2𝑎 +

2𝑎

3 ×

1

4 (Tension)

Influence line for force in member J-I

Fig. 4.14

Cutting the section 5 – 5 as shown above;

I.L for force in member J-I will be given by the I.L for bending moment at

the opposite joint C (triangle) divided by the vertical distance between the

member J-I and the opposite joint C.

I.L at joint C = 𝑥 𝐿−𝑥

𝐿

I.L at member H-G = 𝑥 𝐿−𝑥

𝐿

2𝑕


I.L at member H-G = 2𝑎 8𝑎−2𝑎

8𝑎

2𝑕=

𝟑𝒂

𝟒𝒉 (Tension)

FMax =4𝑊2𝑎

3

(compression)

FMax =𝑊2𝑎

3

(Tension)





I.LH-G=3𝑎

4𝑕

(Tension)

Fig. 4.15: Influence line diagram of member J - I

FMax = W2 × Area of ADG

= 𝑊2 ×1

2× 8𝑎 ×

3𝑎

4𝑕 (Tension)

FORCES IN THE TRUSS MEMBERS

Member Tension (kN) Compression (kN)

FC – D

𝑊28𝑎2

2𝑕

FC – I

𝑊2𝑎 𝑎

2 + 𝑕2

𝑕

𝑊2𝑎 𝑎2 + 𝑕2

𝑕

FD – J

𝑊2𝑎 𝑎

2 + 𝑕2

𝑕

𝑊2𝑎 𝑎2 + 𝑕2

𝑕

FC – J

𝑊2𝑎

3

4𝑊2𝑎

3

FJ – I

3𝑊2𝑎

2

𝑕

Table 1

FMax =3𝑊2𝑎

2

𝑕

(Tension)





4.2 PLASTIC MOMENT ANALYSIS

Fig. 4.16

No of degree of indeterminacy(ID) = 𝑚 + 𝑟 − 2𝑛

Where; m (number of members) = 21

r(number of reactions) = 3

n(number of nodal points) = 10

(ID) = 21 + 3 − 2 × 10 = 4

Unpinning the lower members and the bracing members from the truss

system leaving the frame structure for easy analysis we have;





Fig.

4.17

No of degree of indeterminacy(ID) = 3𝑚 + 𝑟 − 3𝑛



n(number of nodal points) = 13

(ID) = 3 × 9 + 13 − 3 × 10 = 10

No of possible position of hinges = 18

@ Joints B, B1, C(1,2,3), C

1, D(1,2,3), D

1, E(1,2,3), E

1, F, H, I and J.

No of independent collapse mechanism= 18 − 10 = 8

a) 4 Beam mechanisms– Beam B – C

– Beam C – D

– Beam D – E

– Beam E – F

ii) 3 Joint mechanisms – Joint C(1,2,3)

– Joint D(1,2,3)

– Joint E(1,2,3)

iii) 1 sway mechanism

Collapse mechanism 1 – BEAM C – D

Fig. 4.18 W2 = load factor × the imposed loading

𝜕 = 𝑎𝜃 = 𝑎𝛽

∴ 𝜃 = 𝛽

Internal work done (I.W) = 𝑀𝑝 𝜃 + 𝑀𝑝 𝛽 + 𝑀𝑝 𝜃 + 𝛽 = 4𝑀𝑝𝜃

External work done (E.W) = 𝑊2 × 2𝑎 ×𝜕

2

= 𝑎2𝑊2𝜃(𝑘𝑁𝜃𝑚) Considering work equation: Internal work done = External work done

4𝑀𝑝𝜃 = 𝑎2𝑊3𝜃 (𝑘𝑁𝜃𝑚)

∴ 𝑴𝒑 =𝒂𝟐𝑾𝟐

𝟒 (𝒌𝑵𝒎)

Other beam mechanisms (Beams; B – C, D – E and E - F) have the same

methodology and the same Mp with Beam mechanism B – C above.

𝑀𝑝

=𝑎2𝑊2

4 (𝑘𝑁𝑚)





Collapse mechanism 2 – SWAY MECHANISM

Fig. 4.19

𝜕1 = 𝜕2 = 𝜕3 = 𝜕4 = 𝜕5 = 2𝑕𝜃

∴ 𝜃 = 𝛽 Internal work done (I.W)

= 𝑀𝑝 𝜃 + 𝑀𝑝 𝜃 + 𝑀𝑝 𝛽 + 𝑀𝑝 𝜃 + 𝑀𝑝 𝛽 𝑀𝑝 𝜃 + 𝑀𝑝 𝛽 + 𝑀𝑝 𝜃

= 8𝑀𝑝𝜃

External work done (E.W) = 𝑊4 × 𝜕2

= 2𝑕𝜃𝑊4 (𝑘𝑁𝜃𝑚) Considering work equation: Internal work done = External work done

8𝑀𝑝𝜃 = 2𝑕𝜃𝑊4 (𝑘𝑁𝜃𝑚)

∴ 𝑴𝒑 =𝑾𝟒𝒉

𝟒 (𝒌𝑵𝒎)

Collapse mechanism 3 – JOINT MECHANISM {Joint C (1,2,3)}

Fig. 4.20

Considering clockwise rotation in the combine mechanism

1 – (+𝜃)

2 – (−𝜃)

3 – (+𝜃)

Combined mechanism

The independent mechanisms are combined to determine the maximum Mp

value required to induce collapse with the minimum number of hinges.

In this case the following combinations have been evaluated;

I.W= 8𝑀𝑝𝜃 𝐸.𝑊= 2𝑕𝜃𝑊4 (𝑘𝑁𝜃𝑚)

𝑀𝑝

=𝑊4𝑕

4 (𝑘𝑁𝑚)

Member

ref. Calculation Output

DETERMINATION OF THE REACTIONS

Checking collapse mechanism XIV with hinges at B1,C1,C

1,D4,D6,E9,F,H,I





and J (i.e 10 hinges). The value of the Mp obtained 2 𝑎2𝑊2 +2𝑕𝑊4

13𝑘𝑁𝑚

should be checked by ensuring that the bending moment in the frame does

not exceed the relevant Mp value at any location.

Fig. 4.21: Position of Mp on the continuous frame structure

Here W3 (kN) = UDL (W2kN) × bay width (2a m)

Consider the equilibrium of the left-hand side of the frame at B1 and at joint

C1.

Member


Fig. 4.22

+∑ MB1= 0

∴ 𝐴𝑦 × 𝑎 − 𝐴𝑥 × 2𝑕 − 𝑀𝑝 = 0





∴ 𝑎𝐴𝑦 − 2𝑕𝐴𝑥 = 𝑀𝑝 - - - - - - - {1}

Fig. 4.23

+∑ MB1= 0

∴ 𝐴𝑦 × 2𝑎 − 𝐴𝑥 × 2𝑕 − 𝑊3 × 𝑎 + 2𝑀𝑝 = 0

∴ 2𝑎𝐴𝑦 − 2𝑕𝐴𝑥 = 𝑊3𝑎 − 2𝑀𝑝 - - - - - - - {2}

From equation {1}; 𝐴𝑦 =𝑀𝑝+2𝑕𝐴𝑥

𝑎 - - - - - - - - {3}

Substituting the value of Ay in equation {3} into equation {2}we have;

𝑨𝒙 =𝑾𝟑𝒂−𝟒𝑴𝒑

𝟐𝒉(𝒌𝑵) - - - - - - {4}

Substituting the value of Ax in equation {4} into equation {1}we have;

𝑨𝒚 =𝑾𝟑𝒂−𝟑𝑴𝒑

𝒂(𝒌𝑵) - - - - - - {5}

𝐴𝑥 =𝑊3𝑎 − 4𝑀𝑝

2𝑕

(𝑘𝑁)

𝐴𝑦 =𝑊3𝑎 − 3𝑀𝑝

𝑎

(𝑘𝑁)

Member


Considering the equilibrium of the left-hand side of the frame at C1 and at

joint D1.

Fig. 4.24

+∑ MC1= 0

∴ 𝐴𝑦 × 3𝑎 − 𝐴𝑥 × 2𝑕 + 𝐽𝑦 × 𝑎 − 𝐽𝑥 × 2𝑕 − 𝑊3 × 2𝑎 − 𝑀𝑝 −

𝑀𝑝 = 0 - - - - - - - - - - {i}

Substituting the values of Ay and Ax (from equations {5} and {4}

respectively) into equation {i} above we have;

∴ 𝑎𝐽𝑦 − 2𝑕𝐽𝑥 = 7𝑀𝑝 - - - - - - - - {6}





Fig.

4.25

+∑ MD1= 0

∴ 𝐴𝑦 × 4𝑎 − 𝐴𝑥 × 2𝑕 + 𝐽𝑦 × 2𝑎 − 𝐽𝑥 × 2𝑕 − 𝑊3 × 3𝑎 −

𝑊3×𝑎−𝑀𝑝−𝑀𝑝=0 - - - - - - - - - - {ii}

Substituting the values of Ay and Ax (from equations {5} and {4}

respectively) into equation {ii} above we have;

∴ 2𝑎𝐽𝑦 − 2𝑕𝐽𝑥 = 𝑊3𝑎 + 8𝑀𝑝 - - - - - - - - {7}

Member


From equation {6}; 𝐽𝑦 =7𝑀𝑝+2𝑕𝐽𝑥

𝑎 - - - - - - - - {8}

Substituting the value of Jy in equation {8} into equation {7}we have;

𝑱𝒙 =𝑾𝟑𝒂−𝟔𝑴𝒑

𝟐𝒉(𝒌𝑵) - - - - - - {9}

Substituting the value of Jy in equation {9} into equation {8}we have;

𝑱𝒚 =𝑾𝟑𝒂+𝑴𝒑

𝒂(𝒌𝑵) - - - - - - {10}

Considering the equilibrium of the right-hand side of the frame at point F

and E2

Fig. 4.26

+∑ MF= 0

𝐺𝑥 × 2𝑕 − 𝑀𝑝 = 0

∴ 𝑮𝒙 =𝑴𝒑

𝟐𝒉 (kN)- - - - - - - {11}

𝐽𝑥

=𝑊3𝑎 − 6𝑀𝑝

2𝑕(𝑘𝑁)

𝐽𝑦

=𝑊3𝑎 + 𝑀𝑝

𝑎(𝑘𝑁)

𝐺𝑥 =𝑀𝑝

2𝑕(kN)





Fig. 4.27

+∑ MB1= 0

𝐺𝑥 × 2𝑕 − 𝐺𝑦 × 2𝑎 − 𝑊3 × 𝑎 = 0

∴ 𝑮𝒚 =𝑾𝟑𝒂+𝑴𝒑

𝟐𝒂(𝒌𝑵) - - - - - - {12}

𝐺𝑦

=𝑊3𝑎 + 𝑀𝑝

2𝑎(𝑘𝑁)

Member


Considering the equilibrium of the right-hand side of the frame at point E

and D2;

Fig. 4.28 +∑ ME = 0

𝐻𝑥 × 2𝑕 + 𝑀𝑝 −𝑀𝑝 = 0

∴ 𝑯𝒙 = 𝟎 (kN)- - - - - - - {13}

Fig. 4.29

+∑ MD2= 0

∴ 𝐺𝑥 × 2𝑕 − 𝐺𝑦 × 4𝑎 − 𝐻𝑦 × 2𝑎 + 𝐻𝑥 × 2𝑕

+ 𝑊3 × 3𝑎 − 𝑊3 × 𝑎 − 2𝑀𝑝 −𝑀𝑝 = 0

Substituting the values of Gx, Gy and Hx in the equation above we have;

∴ 𝑯𝒚 =𝟐𝑾𝟑𝒂−𝟒𝑴𝒑

𝟐𝒂(𝒌𝑵) - - - - - - {14}

𝐻𝑥 = 0 (kN) 𝐻𝑦

=2𝑊3𝑎 − 4𝑀𝑝

2𝑎(𝑘𝑁)





Considering the equilibrium of forces on the vertical axis to determine Iy

and the equilibrium of forces on the horizontal axis to determine Ix we

have;

Member


+∑ Fy = 0 𝐴𝑦 + 𝐽𝑦 + 𝐼𝑦 + 𝐻𝑦 + 𝐺𝑦 = 4 𝑊3

Substituting the values of 𝐴𝑦 , 𝐽𝑦 ,𝐻𝑦𝑎𝑛𝑑𝐺𝑦 as gotten above into the

equation we have;

∴ 𝑰𝒚 =𝑾𝟑𝒂+𝟕𝑴𝒑

𝟐𝒂(𝒌𝑵) - - - - - - {15}

+∑ FX = 0 𝐴𝑥 + 𝐽𝑥 + 𝐼𝑥 − 𝐻𝑥 − 𝐺𝑥 + 𝑊4 = 0 Substituting the values of 𝐴𝑥 , 𝐽𝑥 ,𝐻𝑥𝑎𝑛𝑑𝐺𝑥 as gotten above into the

equation we have;

∴ 𝑰𝒙 =𝟏𝟏𝑴𝒑−𝟐𝑾𝟑𝒂−𝟐𝑾𝟒𝒉

𝟐𝒉(𝒌𝑵) - - - - - - {16}

Checking for the bending moment at all points of possible hinges to ensure

they are not greater than the Mp value chosen;

Mp at point B

Fig. 4.30

+∑ MB= 0

−𝐴𝑥 × 2𝑕 −𝑀𝑝 = 0(Substituting the value of Ax)

∴ 𝑴𝑩 = 𝟒𝑴𝒑 −𝑾𝟑𝒂 (kNm)- - - - - - - {17}

Mp at point E1

Fig. 4.31

𝐼𝑦

=𝑊3𝑎 + 7𝑀𝑝

2𝑎(𝑘𝑁)

𝐼𝑥

=11𝑀𝑝 − 2𝑊3𝑎 − 2𝑊4𝑕

2𝑕

(kN)

𝑀𝐵 = 4𝑀𝑝 −

𝑊3𝑎(kNm)

+∑ ME1= 0

𝐺𝑥 × 2𝑕 − 𝐺𝑦 × 𝑎 = 0(Substituting the values of Gx and Gy)

∴ 𝑴𝑬𝟏 =𝟑𝑴𝒑−𝑾𝟑𝒂

𝟐 (kNm)- - - - - - - {18}

𝑀𝐸1 =3𝑀𝑝−𝑊3𝑎

2

(kNm)





Mp at point D1

Fig. 4.32

+∑ MD1= 0

∴ 𝐺𝑥 × 2𝑕 − 𝐺𝑦 × 3𝑎 − 𝐻𝑦 × 𝑎 + 𝐻𝑥 × 2𝑕 + 𝑊3 × 2𝑎 −𝑀𝑝

= 0 Substituting the values of Gx, Gy, Hyand Hx in the equation above we have;

∴ 𝑴𝑫𝟏 =𝑴𝒑−𝑾𝟑𝒂

𝟐(𝒌𝑵𝒎) - - - - - - {19}

Mp at point E1

Fig. 4.33

+∑ ME7= 0

∴ 𝐴𝑦 × 6𝑎 − 𝐴𝑥 × 2𝑕 + 𝐽𝑦 × 4𝑎 − 𝐽𝑥 × 2𝑕 + 𝐼𝑦 × 2𝑎

− 𝐼𝑥 × 2𝑕 − 𝑊3 × 5𝑎 − 𝑊3 × 3𝑎 − 𝑊3 × 𝑎 − 2𝑀𝑝 = 0

Substituting the values of Ax, Ay, Jy,Jx, Iy and Ix in the equation above we

have;

∴ 𝑴𝑬𝟏 = 𝟐𝑾𝟑𝒂 + 𝟐𝑾𝟒𝒉 − 𝟏𝟖𝑴𝒑(𝒌𝑵𝒎) - - - - - - {20}

𝑀𝐷1

=𝑀𝑝 −𝑊3𝑎

2(𝑘𝑁𝑚)

𝑀𝐸7

= 2𝑊3𝑎 + 2𝑊4𝑕− 18𝑀𝑝(𝑘𝑁𝑚)

Mp at point C3

Fig. 4.34 +∑ MC3= 0

−𝐽𝑥 × 2𝑕 − 𝑀𝑝 = 0(Substituting the value of Jx)

∴ 𝑴𝑪𝟑 = 𝟓𝑴𝒑 −𝑾𝟑𝒂 (kNm)- - - - - - - {21}

𝑀𝐶3 = 5𝑀𝑝 −

𝑊3𝑎 (kNm)





Member


4.2.1 DETERMINATION OF THE PLASTIC MOMENT IN MEMBER

DLJ (Bracing members)

Fig. 4.35

From pythagora‟s theorem; /DJ/ = 2𝑕 2 + 2𝑎 2

DJ = 2 𝑕2 + 𝑎2(m) - - - - - - - - - {22}

Analyzing member DLJ as a beam mechanism

Let 𝑕2 + 𝑎2 be denoted as “L”

Let the load acting on the bracing members be W6 (kN/m)

Fig. 4.36



DJ =

2 𝑕2 + 𝑎2(m)






n (number of nodal points) = 3

(ID) = 2 × 2 + 3 − 2 × 3 = 1

No of possible position of hinges = 3

@ JointL,udl between point D and L and udl between point L and J

No of independent collapse mechanism= 3 − 1 = 2

Beam mechanisms– Beam B – C and

– Beam C – D

Collapse mechanism 1 – BEAM L – J

Fig. 4.37

Let 𝑕2 + 𝑎2 be “L”

Plastic hinge occurs at the position of maximum moment. Cutting a

section as shown below to determine the position of the maximum moment.

Let “x” be the position of maximum moment from point L and

( 𝑕2 + 𝑎2) − 𝑥 be L – x

Fig. 4.38

+∑ ML= 0

−𝑀𝑝 + 𝑊6 ×𝑥2

2 −𝑀𝑝 = 0

∴ 𝑀𝑝 =𝑊6𝑥

2

4(𝑘𝑁𝑚) - - - - - - {23}

+∑ MJ= 0

𝑀𝑝 −𝑊6

2 𝐿 − 𝑥 2 = 0

∴ 𝑀𝑝 =𝑊6

2 𝐿2 − 2𝐿𝑥 + 𝑥2 (𝑘𝑁𝑚) - - - - - - {24}

Equating equation {23} and {24}

0.25𝑊6𝑥2 = 0.5𝑊6 𝐿

2 − 2𝐿𝑥 + 𝑥2 (making W6 = 1)

∴ 0.25𝑥2 − 𝐿𝑥 + 0.5𝐿2

Appling Almighty formula; 𝑥 =−𝑏± 𝑏2−4𝑎𝑐

2𝑎, 𝑎 = 0.25, 𝑏 = −𝐿, 𝑐 = 0.5

=− −𝐿 ± −𝐿2 − 4 × 0.25 × 0.5𝐿2

2 × 0.25





∴ 𝑥 = 0.586𝐿and 𝐿 − 𝑥 = 𝐿 − 0.586𝐿 = 0.414𝐿

Fig. 4.39

𝜕 = 0.586𝐿𝜃 = 0.414𝐿𝛽

∴ 𝛽 = 1.415𝜃 Internal work done (I.W) = 𝑀𝑝 𝜃 + 𝑀𝑝 𝜃 + 𝛽

∴ 𝑀𝑝 𝜃 + 𝑀𝑝 𝜃 + 1.415𝜃 = 3.415𝑀𝑝𝜃

External work done (E.W= 𝑊6 × 𝐿 ×𝜕

2)

∴ 𝑊6 × 𝐿 ×0.586𝐿𝜃

2

=0.586𝑊6𝐿

2𝜃

2 (𝑘𝑁𝜃𝑚)

Considering work equation: Internal work done = External work done

= 3.415𝑀𝑝𝜃 =0.586𝑊6𝐿

2𝜃

2(𝑘𝑁𝜃𝑚)

∴ 𝑀𝑝 = 0.0932𝑊6𝐿2(𝑘𝑁𝑚)

Substituting the value of L in the equation above we have;

𝑴𝒑 = 𝟎.𝟎𝟗𝟑𝟐𝑾𝟔 𝒉𝟐 + 𝒂𝟐 (𝒌𝑵𝒎)- - - - - - {25}

Due to symmetry, member D-L = member L-J and as such have equal Mp

Fig. 4.39b: Bending moment diagram for member DLJ

𝑀𝑝= 0.0932𝑊6 𝑕

2

+ 𝑎2 (𝑘𝑁𝑚)

4.2.2 DETERMINATION OF THE PLASTIC MOMENT IN

MEMBER A–G (The bottom cord)

Let the total load acting on the lower cord be W7 (kN/m)

Fig. 4.40








n (number of nodal points) = 2

(ID) = 2 × 1 + 2 − 2 × 2 = 0

No of possible position of hinges to cause collapse; 𝐼𝐷 + 1 = 0 + 1 = 1

@ any point under the udl between point A and G (i.e at the middle due to

udl and no moment at the end reactions)

No of independent collapse mechanism= 1

Beam mechanisms– Beam A – G

Fig. 4.41 𝜕 = 𝑎𝜃 = 𝑎𝛽

∴ 𝜃 = 𝛽

Internal work done (I.W) = 𝑀𝑝 𝜃 + 𝛽 = 2𝑀𝑝𝜃

External work done (E.W) = 𝑊7 × 8𝑎 ×𝜕

2

= 𝑊7 × 8𝑎 ×4𝑎𝜃

2

= 16𝑊7𝑎2𝜃 (𝑘𝑁𝜃𝑚)

Considering work equation: Internal work done = External work done

2𝑀𝑝𝜃 = 16𝑊7𝑎2𝜃 (𝑘𝑁𝜃𝑚)

∴ 𝑴𝒑 = 𝟖𝑾𝟕𝒂𝟐 (𝒌𝑵𝒎)- - - - - - {26}

Fig. 4.41b: Bending moment diagram for member A - G AXIAL FORCE DIAGRAM

∴ 𝑀𝑝= 8𝑊7𝑎

2 (𝑘𝑁𝑚)





Fig. 4.42: The axial forces acting on the members of the complex truss system

N.B:The horizontal and vertical forces acting on the internal bracing

members were resolved in the axis on the bracing members to determine

their axial forces.

5.1.1 EC3.

4.3.1 DESIGN METHOD FOR TOP CHORD AND BOTTOM

CHORD (BEAM SECTION)

Beam span = L (8a)m

Bay width = 2a

Actions

Dead load = Gk =

Live load (Qk) = W7kN

Design value of combined actions

= =

W8 kN/m2

UDL per meter length of bean accounting for bay width of 2a=W8x2a

=2aW8=W9 kN/m

Design Moment And Shear Force

Maximum design moment MyEd occurs at mid-span and for bending about

the major (y-y)-axis is My,Ed =𝑊9×𝐿2

8=

𝑊9× 8𝑎 2

8 =8W9a

2kNm - - - - - - {B1}

Maximum design shear force VEd occurs at the end supports, and is;

VEd = 𝑊9×𝐿

2 =

𝑊9×8𝑎

2 = 4W9a kN - - - - - - - - - {B2}

Partial factors for resistance

YM0 = 1.0

Trial Section

Yield strength = fy N/mm2

(lets choose fy to be 275 N/mm2 if tw< 16 mm and for the purpose of

explanation in this project)

The required section needs to have plastic modules about the major-axis

(y-y) that is greater than:

Sy = My ,Ed ×ƳM 0

𝑓𝑦 =

8W9a2×103×1.0

275 (cm

3) - - - - - - - - - {B3}

UDL = W9 (kN)

My,Ed =

8W9a2kNm

VEd =4W9a kN





Sx =8W9a2×103×1.0

275

(cm3)

3.2.6 (1)

Table 5.3.1

of

EC3

Choose a section from table ... with plastic modulus >Sy and select its

properties.

Depth of cross-section = D mm

Web depth = hw mm(hw = h – 2tf)

Width of cross-section = B mm

Depth between fillets = d mm

Web thickness = tw mm

Flange thickness = tf mm

Radius of root fillet = r mm

Cross-sectional area = Acm2

Second moment of area (y-y) = Iy cm4

Second moment of area (x-x) = Ix cm4

Elastic section modulus (y-y)= Ƶeycm3

Plastic section modulus (y-y)=Ƶpycm3

Take modulus of elasticity E to be 210000 N/mm2(for the purpose of

explanation)

Classification of cross-section

ԑ = 235

𝑓𝑦=

235

275= 0.92

Outstand flange under uniform compression

𝑐 = 𝐵−𝑡𝑤−2𝑟

2∴

𝑐

𝑡𝑓= 𝑘𝑓 - - - - - - - - - {B4}

From table 5.3 of EC3, check which class the flange section falls in.

Internal compression part: (web under pure bending)

𝑐 = 𝑑 ∴ 𝑘𝑤 =𝑑

𝑡𝑤- - - - - - - - - {B5}

Also check for the class of the section in the table.

𝑐

𝑡𝑓= 𝑘𝑓

𝑘𝑤 =𝑑

𝑡𝑤

N.B:Both of the flange and the web must fall in one class of section, less

another section that satisfies the condition will be chosen.

We can also go directly to the table (1) and choose the ratios for the local

buckling for flange and web grade them using table 3.

Shear buckling Shear buckling of the unstiffened web need not be considered provided:





6.2.6 (6)

6.2.6 (1)

6.2.6 (2)

6.2.5 (1)

6.2.5 (2)

6.2.8 (2)

6.2.5 (2)

𝑕𝑤

𝑡𝑤≤ 72

𝑒

𝑛∴ n = 1.0 (conservative)

Shear capacity

W9≤ Pv ∴W9

Pv≤ 1.0

Where;𝑃𝑣 =𝐴𝑣

𝑓𝑦 3

Ƴ𝑀0or 0.9fyAv

Av = shear area = tw × D

∴ Pv = 0.6fytwD - - - - - - - - {B6}

If W9<Pv, then shear capacity is adequate

Moment resistance

The design requirement is: 𝑀𝐸𝑑

𝑀𝑐 ,𝑅𝑑≤ 1.0

𝑀𝑐 ,𝑅𝑑 = 𝑀𝑝𝑙 ,𝑅𝑑 =𝑆𝑥×𝑓𝑦

Ƴ𝑀0- - - - - - - - - {B7}

At the point of maximum bending moment the shaer force is zero.

Therefore the bending resistance does not need to be reduced due to the

presence of shear.

∴ 𝑀𝑐 ,𝑅𝑑 =𝑆𝑥×𝑓𝑦

Ƴ𝑀0 - - - - - - - - - {B8}

If MEd≤ Mc,Rd then the design bending resistance of the section is

adequate.

𝑀𝑝𝑙 ,𝑅𝑑 =𝑆𝑥 × 𝑓𝑦

Ƴ𝑀0

𝑀𝑐 ,𝑅𝑑 =𝑆𝑥 × 𝑓𝑦

Ƴ𝑀0

Web bearing and buckling

Pbw = (b1 + nk)twfy - - - - - - - - - {B9}

b1=t + 1.6r + 2tf

k = tf+r

At the end of a member (support)

𝑛 = 2 + 0.6𝑏𝑒

𝑘 but n ≤5 be =0

If W9< Pbwthen, bearing capacity at support is adequate

Serviceability deflection check

Vertical deflection at the mid-span of the beam is determined as:

𝜕 = 5L4W

384𝐸𝐼 - - - - - - - - - {B10}

=5 × 8𝑎 × 103 × 𝑊3 × 2𝑎

384 × 𝐸 × 𝐼

Vertical deflection limit of the beam = 𝑠𝑝𝑎𝑛

360=

8𝑎×103

360= V

If 𝜕< V then the vertical deflection of the section is satisfactory.

Pbw = (b1 + nk)twfy

𝜕 = 5L4W

384𝐸𝐼





BS EN

1993-1-1

NA 2.23

V= 𝑠𝑝𝑎𝑛

360

6.1(1)

NA 2.15

4.3.2 DESIGN OF VERTICAL MEMBERS (COLUMNS/STRUTS)

(COMPRESSION MEMBERS)

Moment = M

Sy = M

fy (cm

3) where;fy = 275 N/mm

2

Data

Axial force = N

Design moment (Mi)= 𝑀

2- - - - - - - - - {C1}

Partial factors for resistance ƳM0 = 1.05

ƳM1 = 1.0

Trial section Initial trial section is selected to give a suitable moment capacity. The size

is then checked to ensure suitability in all other aspects.

Choose a section from table… with plastic modulus >Syand select its

properties.

Section Properties

Depth of cross-section = D mm

Width of cross-section = B mm

Depth between fillets = d mm

Web thickness = tw mm

Flange thickness = tf mm

Cross-sectional area = Acm2

Second moment of area (y-y) = Iy cm4

Elastic section modulus (y-y) = Ƶeycm3

Plastic section modulus (y-y)=Ƶpycm3

Sy = M

fy (cm

3)

Mi= 𝑀

2





SN048a-

EN- GB

Access

Steel

document

In-plane failure about major axis

Members subject to axial compression and major axis bending must

satisfy. 𝑁

𝑁𝑏 .𝑦 .𝑅𝑑+

𝑘𝑦𝑀𝑖𝑦

𝑛𝑀𝑐 .𝑦 .𝑅𝑑≤ 1.0 - - - - - - - - - {C5}

𝑁𝑏 .𝑦 .𝑅𝑑 =𝐵𝐴𝑓𝑐𝐴

Ƴ𝑀1 - - - - - - - - - {C6}

Mc.y.Rd = Moment capacity of column (gotten above).

But: Iy = 0.85L (Restrained about both axis)

= 0.85 × 2h × 103 = 1.7h × 10

3and

Slenderness ratio: 𝜆𝑦 =𝐼𝑦

𝑖𝑦- - - - - - - - - {C7}

Buckling about y-y axis (curve b)

BA = 1

𝜆𝑦 𝐵𝐴 ≤ 𝑡𝑓

Interpolate (from table…) where necessary to get the value of fc then

substitute in equation C6.

ky = 1.5 (conservative value)

𝑛 =Ƴ𝑀0

Ƴ𝑀1

= 1

Substitute values in equation C5

If the condition is satisfied then, the section has sufficient resistance

against in plane failure against major axis.

𝑁

𝑁𝑏 .𝑦 .𝑅𝑑

+𝑘𝑦𝑀𝑖𝑦

𝑛𝑀𝑐 .𝑦 .𝑅𝑑

≤ 1.0

Iy = 1.7h × 10

3

𝜆𝑦 =𝐼𝑦

𝑖𝑦

𝑛 =Ƴ𝑀0

Ƴ𝑀1

= 1

PUnless

stated

otherwise

4.3.3 DESIGN OF BRACING AND BRACING CONNECTIONS

Design summary:





all

references

are

to BS EN

1993-1-1

BS EN

1991-1-4

BS EN

1990

NA 2.2.3.2

Table

NA.A1.2(B

)

(a) The wind loading at each beam is transferred to two vertically braced

end bays on grid lines „A‟ and „J‟ by the beams acting as diaphragms.

(b) The bracing system must carry the equivalent horizontal forces(EHF)

in addition to the wind loads.

(c) Locally, the bracing must carry additional loads due to imperfections at

splices (cl 5.3.3(4)) and restraint forces (cl5.3.2(5)). These imperfections

are considered in turn inconjunction with external lateral loads but not at

the same time as the EHF.

(d) The braced bays, acting as vertical pin-jointed frames, transfer the

horizontal wind load to the ground.

(e) The beams and columns that make up the bracing system have already

been designed for gravity loads1). Therefore, only the diagonal members

have to be designed and only the forces in these members have to be

calculated.

(f) All the diagonal members are of the same section, thus, only the most

heavily loaded member has to be designed.

Forces in the bracing system

Let the total overall un-factored wind load be W11 (kN)

W11 × tan-1

2𝑕

2𝑎 = W11b

With two braced bays, total un-factored load to be resisted by each

braced bay = 0.5 × W11b = W12 (kN) - - - - - - - - - - - {D1}

Ultimate Limit State (ULS)

Partial factors for actions

Partial factor for permanent actions ƳG= 1.35

Partial factor for variable actions ƳQ = 1.5

Reduction factor 0.925 =ڠ

Reg no – 2010224929Designed by –Onunkwo Raphael C.

Date – 24/09/2015Sheet No - 37

Member


Design wind load at ULS

Using Equation 6.10b in EC3 1990 with wind as the leading variable action,

the design wind load per braced bay is:

W13 (kN)= 1.5 × W12kN - - - - - - - - - - - {D2}

Horizontal component of force in bracing member = 1.5W12 (kN)

Vertical component of force in bracing member

=1.5𝑊12

2𝑎× 2𝑕 =

3𝑊12𝑕

2𝑎 (𝑘𝑁)





NA 2.15

BS EN

1993-

1-8

NA 2.3

Table

NA.1

Axial force in bracing (N) = 1.5𝑊12 2 +

3𝑊12𝑕

2𝑎

2

- - - - - {D3}

Partial factors for resistance

ƳM0 = 1.0

ƳM1 = 1.0

ƳM2 =1.25 (for bolts and welds)

Trial section Choose a trial section from table 3 in appendix and select their properties.

Section properties Area = A cm²

Second moment of area = I cm4

Radius of gyration = i cm

Thickness = t = 10.0 mm

Ratio for local Buckling = d /t

NA 2.4

BS EN

10210-1

Table A3

Table

5.3.1 6.2.4(1)

Eq. 6.9

6.2.4(2)

Eq. 6.10

Material properties

Steel grade = S355

Ift ≤ 16 mm, then, Yield strength fy = 355 N/mm²

3.2.6 (1) modulus of elasticity E = 210 kN/mm²

Section classification

𝜀 = 235

𝑓𝑦- - - - - - - - - - - {D4}

Check for the classification of section in EC3 table 5.3.1

Design of member in compression

Cross sectional resistance to axial compression

Basic requirement; 𝑁

𝑁𝑐 ,𝑅𝑑≤ 1.0- - - - - - - - - - - {D5}

N - is the design value of the applied axial force

Nc,Rd- is the design resistance of the cross-section for uniform compression.

where;

𝑁𝑐 ,𝑅𝑑 =𝐴×𝑓𝑦

𝛾𝑀0(For Class 1, 2 and 3 cross-sections) - - - - - - {D6}

If equation D5 is satisfied, then the resistance of the cross-section is

adequate.

Flexural buckling resistance





6.3.1.1(1)

Eq. 6.46

For a uniform member under axial compression the basic requirement

is: 𝑁

𝑁𝑏 ,𝑅𝑑≤ 1.0- - - - - - - - - - - {D7}

Nb,Rd- is the design buckling resistance and is determined from;

𝑁𝑏 ,𝑅𝑑 =𝜒𝐴𝑓𝑦

𝛾𝑀1(For Class 1, 2 and 3 cross-sections) - - - - - - {D8}

6.3.1.2(1)

Table 6.2 Table 5.2

Table 5.5.2

6.2.3

𝜒 is the reduction factor for buckling and may be determined from

Figure 6.4.

For hot finished CHS in grade S355 steel use buckling curve „a‟

For flexural buckling the slenderness is determined from:

ƛ = 𝐴𝑓𝑦

𝑁𝑐𝑟=

𝐿𝑐𝑟

𝑖

1

𝜆1 (For Class 1, 2 and 3 cross-sections)

As the bracing member is pinned at both ends, conservatively take:

𝐿𝑐𝑟 = 𝐿 = 2𝑎 2 + 2𝑕 2

where;

Lcr = is the buckling length

i = is the radius of gyration

𝜆1 = 93.9ԑ

∴ ƛ = 2𝑎 2+ 2𝑕 2

𝑖

1

93.9ԑ - - - - - - - - - - - {D9}

From buckling curve „a‟, find the equivalent value of 𝜒that corresponds

with the value of ƛ gotten in equation D8.

If equation D7 is satisfied, then the flexural buckling resistance of the

section is adequate.

Design of member in tension

When the wind is applied in the opposite direction, the bracingmember

considered above will be loaded in tension. By inspection,the tensile

capacity is equal to the cross-sectional resistance.

Use buckling

curve „a‟





P363

BS EN

1993-

1-8

Table 3.1

RESISTANCE OF CONNECTION Assume the CHS is connected to the frame via gusset plates. Flatend plates

fit into slots in the CHS section and are fillet welded tothe CHS. Bolts in

clearance holes transfer the load between theend plate and gusset plates.

Verify the connection resistance “N”kN tensile force.

Fig. 4.43: Bracing setting out and connection detail

Try: 8 No non-preloaded Class 8.8 M24 diameter bolts in 26 mmdiameter

clearance holes.

Assume shear plane passes through the threaded part of the bolt

Cross section area, = A mm²

Clearance hole diameter, d0 = 26 mm

For Class 8.8 non-preloaded bolts:

Yield strength fyb = 640 N/mm2

Ultimate tensile strengthfub = 800 N/mm2

Positioning of holes for bolts:

(Minimum) End distance (e1) = 1.2 d0< e1 = 40 mm

(Minimum) Edge distance (e2) = 1.2 d0< e2 = 60 mm

(Minimum) Spacing (p1) = 2.2 d0< p1 = 80 mm

(Minimum) Spacing (p2) = 2.4 d0< p2 = 130 mm

(Maximum) e1and e2,

larger of 8t > 40 mm and 60 mm

(Maximum) p1and p2





BS EN

1993-1-8

Figure 3.1

BS EN

1993-1-8

Table 3.4

Smaller of 14t > 80 mm and 130 mm

If satisfied, then bolt spacings comply with the limits.

Fig. 4.44: Positioning of holes for bolts

Choose the grade and section of end plate thick to fit into a slotted hole in

the CHS

Shear resistance of bolts:

The resistance of a single bolt in shear is determined from:

𝐹𝑣,𝑅𝑑 =𝑎𝑣𝑓𝑢𝑏 𝐴

𝛾𝑀2- - - - - - - - - - - {D10}

Where;av = 0.6 for grade 8.8 bolts

Mininum number of bolts “n” required is; 𝑁

𝐹𝑣,𝑅𝑑 = „n‟ bolts - - - - - - - - - - - {D11}

Then provide no of bolts > n number of bolts gotten in equation D11 above.

𝐹𝑣,𝑅𝑑 =𝑎𝑣𝑓𝑢𝑏𝐴

𝛾𝑀2

𝑁

𝐹𝑣,𝑅𝑑

= 𝑛

BS EN

1993-1-1

NA 2.4

BS EN

10025-2

Table 7

BS EN

1993-1-8

Table 3.4

Bearing resistance of bolts

Assume gusset plate has a thickness no less than the 15 mm endplate.

End plate is a grade S275 and if t ≤ 16 mm, for S275 steel, then yield

strength,fy = 275 N/mm²

if 3 ≤ t ≤ 100 mm; then ultimate tensile strength fu = 410 N/mm²

The bearing resistance of a single bolt is determined from;

𝐹𝑏 ,𝑅𝑑 =𝑘1𝑎𝑏𝑓𝑢𝑑𝑡

Ƴ𝑀2 - - - - - - - - - - {D12}

Where;

ab is the least value of 𝛼𝑑 ,𝑓𝑢𝑏

𝑓𝑢 ,𝑝 , and 1.0

For end bolts, 𝑎𝑑 =𝑒1

3𝑑0- - - - - - - - - - {D13}

For inner bolts, 𝑎𝑑 =𝑒1

3𝑑0−

1

4- - - - - - - - - - {D14}

𝑓𝑢𝑏

𝑓𝑢 ,𝑝= 𝑎𝑧- - - - - - - - - - {D15}

The lowest among the values gotten from equations D13, D14, D15 and

1.0 is taken as the value of “ab”

For edge bolts k1 is the smaller of; 2.8𝑒2

𝑑0− 1.7 or 2.5

For inner bolts k1 is the smaller of; 1.4𝑝2

𝑑0− 1.7 or 2.5

Therefore, choose the value of k1 from above and substitute the values

gotten in equation D12

Resistance of all six bolts in bearing may be conservatively taken as:

𝐹𝑏 ,𝑅𝑑 =𝑘1𝑎𝑏𝑓𝑢𝑑𝑡

Ƴ𝑀2





8 × Fb,RdkN

BS EN

1993-1-8

3.7

BS EN

1993-1-8

3.10.2

6.2.3(1)

6.2.3(2)

Eqn. 6.6

Group of fasteners

Because the shear resistance of the bolts is less than theminimum bearing

resistance of any bolt, the designresistance of the group is taken as:

8 × Fv,Rd = FGp (kN)

Tensile resistance of end plate (see Figure 9.4)

Two modes of failure are to be considered:

i) Cross-sectional failure and

ii) Block tearing failure.

Fig. 4.45: Plate failure modes

i) Cross-sectional failure:

Basic requirement: 𝑁

𝑁𝑡 ,𝑅𝑑≤ 1.0- - - - - - - - - - {D16}

For a cross-section with holes, the design tensile resistance istaken as the

smaller of Npl,Rd and Nu,Rd:

𝑁𝑝𝑙 ,𝑅𝑑 =𝐴𝑔×𝑓𝑦

𝛾𝑀0- - - - - - - - - - {D17}

Where; Ag = A × tp (the gross cross-sectional area)

If Npl,Rd> N, then OK

Resistance of the

bolt group =

FGp(kN)

𝑁𝑝𝑙 ,𝑅𝑑 =𝐴𝑔𝑓𝑦

𝛾𝑀0





Eqn. 6.7

6.2.2.2

BS EN

1993-1-8

3.10.2 (2)

𝑁𝑢 ,𝑅𝑑 =0.9×𝐴𝑛𝑒𝑡 ×𝑓𝑢

𝛾𝑀2- - - - - - - - - - {D18}

Where;

𝐴𝑛𝑒𝑡 = 𝐴 − 2 × 𝑑0 × 𝑡𝑝 here tp = 15

If Nu,Rd> N then, OK

ii) Block tearing failure

For a symmetric bolt group subject to concentric loading, the design block

tearing resistance (VEff,1,Rd) is determined from:

𝑉𝐸𝑓𝑓 ,1,𝑅𝑑 =𝑓𝑢𝐴𝑛𝑡

𝛾𝑀2+

1

3

𝑓𝑦𝐴𝑛𝑣

𝛾𝑀0 - - - - - - - - - - {D19}

Where;

Ant is the net area subject to tension

Anv is the net area subject to shear

Ant is the minimum of 𝑃2 − 𝑑0 𝑡𝑝 and 2 𝑒2 − 0.5𝑑0 𝑡𝑝and

𝐴𝑛𝑣 = 2 3𝑝1 + 𝑒1 − 2.5𝑑0 𝑡𝑝

Substitute the values of Ant and Anv in equation D16

If VEff,1,Rd> N then, OK

𝑁𝑢 ,𝑅𝑑

=0.9𝐴𝑛𝑒𝑡 𝑓𝑢

𝛾𝑀2

𝑉𝐸𝑓𝑓 ,1,𝑅𝑑

=𝑓𝑢𝐴𝑛𝑡𝛾𝑀2

+ 1

3

𝑓𝑦𝐴𝑛𝑣

𝛾𝑀0

Discussion and Conclusion: the summary for the study on the comparison between elastic analysis and plastic analysis for the design of

complex truss.

In this lesson we have studied how the loads are transferred in bridge truss floor system. Further, we found

that there is similarity between the influence line of support reactions for simply supported beam and truss

structures. Finally we studied the influence line for truss member forces.

Influence lines as we have seen is a function whose value at any given point represents the value of some

structural quantity due to a unit force placed at that point. The influence line graphically shows how changing

the position of a single load influences various significant structural quantities. (Structural quantities:

Reactions, Shear, Moment, Deflection, etc.)





Influence lines may be used to advantage in the determination of simple beam reactions. In this case, the use

of the unit influence line is necessary. The unit influence line represents the effects of unit: reactions

(displacements), shears (separations) and moments (rotations) in a beam structure.

We have also seen how plastic method of analysis can be used to analyse not just truss systems but the

complex truss systems. Unpinning the members of the truss system makes it very much easier and very much

explanatory in the analysis of the truss systems.

Plastic analysis of the complex truss system as we have seen agrees to the theory of plasticity which says that

a structure is deemed to have reached the limits of its load bearing capacity when it forms sufficient hinges to

convert it to a mechanism with consequent collapse. This is normally one hinge more than number of degree

of indeterminacy (Ip).

The plastic collapse loads corresponding to various failure mechanisms as we have seen are obtained by

equating the internal work at the plastic hinges to the external by loads during the virtual displacement. This

requires evaluation of displacements and plastic hinge rotations.

During the last few decades, computer software has become more and more critical in the analysis of

engineering and scientific problems. Much of the reason for this change from manual methods has been the

advancement of computer techniques developed by the research community and, in particular, universities.

As both the Technology and Engineering industries advance, new methodologies of interlinking and

complementing the industries via computer applications will be created, with a similar improvement in

hardware capacities. This in turn will facilitate the implementation of more efficient and professional

engineering software. As these software applications advance in functionality, one can hope that they will be

more affordable so as to promote their widespread usage amongst civil engineers at a global scale.

The introduction of software usage in the civil engineering industry as we have seen has greatly reduced the

complexities of different aspects in the analysis and design of projects, as well as reducing the amount of time

necessary to complete the designs. Concurrently, this leads to greater savings and reductions in costs. More

complex projects that were almost impossible to work out several years ago are now easily solved with the use

of computers. In order to stay at the pinnacle of any industry, one needs to keep at par with the latest

technological advancements which accelerate work timeframes and accuracy without decreasing the reliability

and efficiency of the results.

Plastic analysis vs elastic analysis It may not be realized, but the advantages of plasticity of metal are consciously or unconsciously

made use of even in elastic design methods. For example, in the elastic method of design, if a design

is too conservative for a given permissible working stress, then the stress value is changed, indicating

that plasticity is made use of.

Advantages of the plastic method of analysis Normally, there are two distinct advantages of plastic methods over the conventional or elastic methods.

Firstly, they are more economical as they make full use of the materials strength beyond the elastic limit.

Secondly, the design procedures are much simpler and rational.

It has been observed earlier that metals, especially steel have considerable reserve of strength beyond that

elastic limit. Also, ultimate load for these can be computed more precisely and accurately. Taking advantage

of the above, the plastic methods permit use of much smaller structural section to safely support the working

loads. As regards simplicity of procedures, the plastic methods are inherently simple, as they do not take

consideration the elastic conditions of continuity, which involves tedious and complicated calculations. It is

for these reasons that plastic design methods are calculated.

In the influence line analysis, the mobile load acting on the truss system was directly applied in the

determination of the axial forces acting on the respective truss members where as for the plastic analysis

method the mobile load has to be multiplied with the section‟s load factor before analysis.

From the influence line analysis, I observed that the top chord members of the truss system are all

compression members, the lower chord members are all tension members then both the vertical strut and

braced members are being acted upon by both compression and tension forces.

The internal braced members of the truss system exist both in primary and secondary truss and has to be

designed accordingly. I also noticed that after analysis, the result showed that the braced members have the

same magnitude of compressive and tension forces.

In the influence line analysis of the complex truss designed in chapter four, the effect of the mobile load on the

truss members is highest when the position of the mobile load is at the middle of the truss system. To obtain

the maximum value of a function due to a single concentrated live load, the load should be placed at that point

where the ordinate to the influence line for that function is a maximum.





The value of a function due to the action of a single concentrated live load equals the product of the magnitude

of the load and the ordinate to the influence line for that function, measured at the point of application of load.

It is only when the reduced frame structure is pinned at the both ends and fixed at the internal support that it

will satisfy the required number of independent collapse mechanism. From the table of the combined

mechanism, It was observed that the highest Mp value required to induce collapse is 2 𝑎2𝑊2 +2𝑕𝑊4

13𝑘𝑁𝑚 and

occurs at column 13 of the table.

From the results of the reactions obtained in chapter four from the plastic method of truss analysis, the

maximum compressive axial force acting on the vertical members occurs at point J (Jy) and the maximum

tension axial force acting at the lower chord member occurs at point I (Ix)

When checking for the bending moment at all points of possible hinges, I observed that the Mps gotten are

higher than the required Mp gotten from the combined mechanism. Nevertheless, the maximum bending

moment which occurs at point E7 and C3 will be used as the design moment gotten from the plastic method of

analysis. The lower chord and the bracing members have their own respective Mps which are 8W7a2 kNm and

0.0932W6 h2 + a2 kNm respectively.

A close examination on the chapter four of this project disputes the advantages listed above in 5.3, when it

comes to the analysis of complicated truss systems acted upon by mobile loads. Unlike beams and frames truss

systems involve a combination of many members and as such it requires a lot of rigorous processes and

assumptions especially when using the plastic analysis method.

On the basis of economy, plastic method of analysis is mainly economical when it comes to the analysis of

frames and beams. When it comes to complicated truss systems acted upon by mobile load, the use of

influence line is much safer.

Plastic method of analysis does not give a clear effect of the mobile load on each member with respect to the

position of the mobile load. The use of influence line analysis gives directly the axial force exerted by the

mobile load on each truss member with respect to it‟s position.

The top chord and the strut (column) members have the same moment (i.e the maximum Mp value) when using

plastic method of analysis. With elastic method of analysis the top chord and the strut members do not have

the same design moment.

The results obtained from the research of this work shows that the influence line analysis generates higher

axial forces on members than with the plastic analysis method under the same magnitude of imposed live

loads. This is so because the plastic method of analysis involves a lot of assumptions that makes it yet not

advisable to be used in the analyses of trusses carrying mobile loads.

Influence line for mobile load analysis is easily written in a programmable form because it is easier and gives

the required axial forces directly than the plastic method of mobile analysis.

A user-friendly program for the computer analysis of influence line and plastic method of analyzing

complicated truss system and design of steel trusses has been successfully created and tested for the following:

Trussanalysis with the following variable input parameters:

Span length

Span height

Type and intensity of loading

The program instantaneously calculates and displays the following results using the above parameters:

The total axial forces acting on each member of the truss system for influence line analysis

The maximum Mp values that will be acting on the truss members for plastic method of analysis

The axial and the shear forces acting on each member when using the plastic method of analysis.

The wind loading at each beam is transferred to two vertically braced end bays on grid lines „A‟ and „J‟ by the

beams acting as diaphragms. The bracing systemcarrys the equivalent horizontal forces (EHF) in addition to

the wind loads.Locally, the bracing must carry additional loads due to imperfections at splices (cl 5.3.3(4)) and

restraint forces (cl 5.3.2(5)). These imperfections are considered in turn in conjunction with external lateral

loads but not at the same time as the EHF.The braced bays, acting as vertical pin-jointed frames, transfer the

horizontal wind load to the lower chord members.The beams and columns that make up the bracing system

have already been designed for gravity loads1). Therefore, only the diagonal members have to be designed and

only the forces in these members have to be calculated.All the diagonal members are of the same section, thus,

only the most heavily loaded member has to be designed.

Finally, there is always an assumption that trusses cannot be analysed using plastic method of analysis since

they (trusses) are subjected to axial forces and not bending. But from the research shown above in chapter

four, we have seen that trusses can be analysed using plastic moment analysis if the necessary steps are being

followed.

In this work, we have also seen how trusses can be designed using the current code for design regulation, the





Euro code 3.

Recommendation: The recommendations directly affiliated with this project are given as follows:

a) The use of influence line analysis should be used for the analysis of complicated truss systems carrying mobile

loads (e.g. bridge trusses), since it gives directly the design axial forces on each member.

b) More research or experiment should be made on plastic method of analysis of truss systems acted upon by

mobile or static loads in order to discover more benefits of using the plastic method of analysis for truss

systems.

c) Conscientious effort should be made to expose undergraduate students to the use of plastic method of analysis

in order to sensitize its use in the would be engineers.

d) To continue developing, expanding and improving this software application hoping that one day, it will be a

full structural analysis program catering for the analysis and design of frames, trusses and other structural

elements.

e) The Department of Civil Engineering at NnamdiAzikiweUniversityshould introduce a computer lab for use by

students so as to promote the use of computers in the engineering profession.

f) The department should encourage conducting similar final year projects dealing with computer applications in

the future.

g) More emphasis regarding computer technology and applications to engineering should be made at an academic

level in different courses. This would broaden the intellect of students as well as expose them to new

technologies in all engineering disciplines.

h) Civil engineering students should be thought on the use of Euro codes which is the new code for the design of

civil engineering structures as against the BS codes.

i) Modern buildings are being built using steel materials. Students/engineers should be encouraged to learn the

design of steel structures (e.g. trusses, frames, buildings e.t.c.) according to EC3 in order to suite the

contemporary world.

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