Experimental Study of Multi Storey Building with Dynamic ...ijetmas.com/admin/resources/project/paper/f201704231492948899.pdfshear wall and tuned mass damper. A multi degree of freedom

International Journal of Engineering Technology, Management and Applied Sciences

www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476

415 Savan Vadariya, Dr. V. R. Panchal, Ms. Neha Chauhan

Experimental Study of Multi Storey Building with Dynamic

Response Control System using Shake Table

Savan Vadariya

Postgraduate Student

M. S. Patel department of civil

engineering

CSPIT, CHARUSAT, Changa,

India

Dr. V. R. Panchal

Professor and Head of

department


engineering

CSPIT, CHARUSAT, Changa,

India

Ms. Neha Chauhan

Assistant Professor


engineering

CSPIT, CHARUSAT, Changa

India

ABSTRACT

Dynamic properties and dynamic response of any structure can be achieved by making model of the building and tested

with appropriate equipment. It has been found from various literary works that, various researchers have attempted

various sorts of response control frameworks like active, passive and hybrid. The experimental work will be carried out

considering the multi degree of freedom system (MDOF) with response control systems like shear wall, bracings, tuned

mass damper (TMD) and multiple tuned mass damper (MTMD) and without response control systems. Properties of the

building model are achieved by conducting free vibration tests with the help of shake table, accelerometers, data

acquisition system. The tests result of controlled system was compared with uncontrolled systems. In this paper,

experimental study of a building model with bracing, shear wall, TMD and MTMD has been carried out. Three bracing

system has been considered for study i.e. inclined, concentric and eccentric. Shear wall is considered on individual floor

and from bottom to top of building. TMD is considered at the center of mass at every floor, considering 5% mass of

whole building. For MTMD five TMD has been considered in single floor, placed at four corner and at center of floor.

Experimental results are obtained in form of storey displacement, fundamental frequency and time period. The result

shows that building with shear wall at all storey, cross inclined bracing, eccentric bracing and tuned mass damper at top

floor shows maximum reduction in time period and displacement as compared to other controlled system.

Keywords

Dynamic response, shear wall, bracing, tuned mass damper (TMD), multiple tuned mass damper (MTMD).

1. INTRODUCTION

Earthquake is one of the major natural hazards to the life on the earth and has affected numerous cities and

villages of almost every continent. The damages caused by earthquakes are mostly to manmade structures.

Numbers of earthquake occurs all over the world every year and it take numbers of lives of people. Thus, it is

compulsory to design structures that are earthquake resistant. The dynamic behavior of a structure during

earthquake is different from the static condition. The structure responds dynamically during earthquake.

Researchers been studied various types of dynamic response control have in past. At present, passive way of

increasing stiffness and damping to structure is accepted for dynamic response control by using bracings,

shear wall and tuned mass damper. A multi degree of freedom system consisting of spring mass model with

four degree of freedom system made up from aluminum material building model is considered for

experimental work.

Properties of the MDOF model are achieved by conducting free vibration tests with the help of shake table,

accelerometers, data acquisition system. Four storey MDOF model made of four floor slab weighing 1.500 kg

each and aluminum column weighing 405 grams/m with stiffness of 5822 N/m. The frequency for experiment




is taken in range of 0.30 Hz to 20Hz with constant increment. Fundamental frequency of four storey MDOF

model is calculated 5.17 Hz by conducting experiment. Firstly, all the experiments were carried out on

uncontrolled building model. Afterward, uncontrolled model was replaced by the controlled model to find the

dynamic properties & responses of building model.

2. DYNAMIC RESPONSE CONTROL SYSTEMS

2.1Shear wall

Shear wall is most commonly used lateral load resisting systems in buildings. In medium rise to high rise RCC

buildings, shear walls are very effective in seismic load resistance. Shear walls have very high in-plane

stiffness and strength, which can be used at the same time to support gravity loads and resist lateral loads,

making them useful in seismic performance of buildings. Shear walls are vertical elements of the horizontal

force resisting system. Shear walls are like vertically-oriented wide beams that carry earthquake loads

transfers to the foundation. Firoozabad et al. (2012)studied on the dynamic response of building with various

shear wall configuration and their influence on seismic behavior of building. Since 1970’s, steel shear walls

have been used as the main lateral load resisting system in numerous modern and important structures. The

main function of steel plate shear wall is to resist overturning moment due to lateral loads and horizontal story

shear. In simple words, steel plate shear wall system contains of a steel plate wall, horizontal floor beams and

two boundary columns. 2 mm thick aluminum made shear plate is used for experimental work. Five types of

shear wall system were consider for study. Out of five, four were with shear wall at four sides on ground floor,

first floor, second floor and top floor and the remaining one was on all four floor.

(a) (b) (c) (d) (e)

Figure 1. Four storey building model with shear wall at various storey




Figure 2. Comparison of time period for building with shear wall at various storey

Figure 2 shows the comparison of time period for four storey building model with shear wall at different

storey. It is also derived from the Figure 2 that building model with shear wall at all storey shows maximum

reduction in time period.

Figure 3. Displacement response of Mass 1, Mass 2, Mass 3 and Mass 4 for building with shear

wall at various storey




Figure 3 shows maximum displacement at fundamental frequency for Mass 1, Mass 2, Mass 3 and Mass 4 of

four storey building with shear wall at various floor. It is also derived from the Figure 3 that building model

with shear wall at every floor shows maximum reduction in displacement response

2.2 Bracing

Bracing system was used to add further stiffness & damping to the building model representing four MDOF

system. Purohit and Panchal (2013) studied behavior of single degree of freedom system (SDOF) building

with bracing. The bracings are made up of a linear spring of sufficient stiffness provided in between two

aluminum strip. The spring’s stiffness was measure to be 350 N/m in laboratory with load-deflection curve.

The spring was used as a bracing component to act pure compressive and tensile forces in the inclined

members without buckling. Therefore, it was essential to make the spring straight and stretch without getting

bend out end. To control the spring movement and to convey lateral band PVC pipe segment was used. For

experimental study, three types of bracing systems considered are (a) Inclined bracing system (b) Concentric

bracing system and (c) Eccentric bracing system. For inclined bracing system, (i) inclined bracing and (ii)

cross inclined bracing are considered. For concentric and eccentric bracing system, four types of bracing

considered are (i) V (ii) inverted V (iii) double inclined and (iv) right angle triangle bracing.

2.2.1 Inclined bracing system

For experiment, two types of inclined bracing systems namely inclined bracing and cross inclined bracing (X)

are considered (Figure 4).

(a) (b)

Figure 4. Inclined bracing system




Figure 5 shows the maximum displacement at fundamental frequency for Mass 1, Mass 2, Mass 3 and Mass 4

of building with inclined bracing system. It is also derived from the Figure 5 that cross inclined bracing

system control maximum displacement response.

2.2.2 Concentric bracing system

Four types of concentric bracing systems (a) inverted V, (b) V, (c) right angle triangle and (d) double inclined

bracing are considered for experiment work (Figure 6).

Figure 5. Displacement response of Mass 1, Mass 2, Mass 3 and Mass 4 for inclined bracing

system




(a) (b)

(c) (d)

Figure 6. Concentric bracing system

Figure 7. Displacement response of Mass 1, Mass 2, Mass 3 and Mass 4 for concentric bracing system




Figure 7 shows maximum displacement response at fundamental frequency of Mass 1, Mass 2, Mass 3 and

Mass 4 for concentric bracing system. It is also derived from the Figure 7 that double inclined concentric

bracing system shows maximum displacement control.

2.2.3 Eccentric bracing system

Four types of eccentric bracing system (a) inverted V, (b) V, (c) right angle triangle and (d) double inclined

bracing are considered for experiment work (Figure 8).

(a) (b) (c) (d)

Figure 8. Eccentric bracing system

Figure 9. Displacement response of Mass 1, Mass 2, Mass 3 and Mass 4 for eccentric bracing system





Mass 4 for eccentric bracing system. It is also derived from the Figure 9 that inverted V eccentric bracing

system shows maximum displacement response control.

Figure 10 shows the comparison of time period for building with bracing system. It is also derived from the

Figure 10 that double inclined concentric bracing system shows maximum reduction in time period.

2.3 Tuned mass damper

Frahm introduced the concept of the TMD in 1909. TMD is a passive energy dissipation device. To decrease

the motion of the systems under harmonic excitations, TMD is used in the structural systems and machines.

Later, Hartog suggested an ideal design theory of the TMD for an undamped SDOF system subjected to

harmonic excitation in the 1940s. TMD is a dynamic vibration absorber containing of secondary mass on the

order of 5% of the mass of the building, tuned to the frequency of the building by attaching it through a spring

steel strip. This mass is mostly located at the top of the building. TMD’s frequency is tuned to a exact ratio of

the modal frequency such that its motion becomes out of phase to that of the motion of the structure. Rana and

Soong (1998) gives the formulas and design procedure to find out different parameter for tuned mass damper.

Handayani et al. (2008)studied behavior of MTMD. The design parameters of the TMD were selected as that

MDOF system is most effectively controlled by the TMD. The value of the design parameters of the TMD is:

Mass ratio = 7%

Stiffness = 403.2 N/m

Mass = 350 grams

Different configuration are considered for tuned mass damper (a) By placing single tuned mass damper at

each four storey and (b) By placing multiple tuned mass damper at each storey. For MTMD five tuned mass

damper had been taken for experiment work.

2.3.1 Single Tuned mass damper

Four storey building with tuned mass damper on center of floor mass at various floor is considered for

experiment work (Figure 11).

Figure 10. Comparison of time period for different building model with various bracing system




(a) (b) (c) (d)

Figure 11. Four storey model with tuned mass damper at various floor




Figure 12 shows maximum displacement response at fundamental frequency of Mass1, Mass 2, Mass 3 and

Mass 4 for building model with single tuned mass damper at various floor. It is also derived from the Figure

12 that single tuned mass damper at top floor shows maximum displacement response control.

2.3.2 Multiple tuned mass damper

Four storey building with multiple tuned mass damper at various floor is considered for experiment work.

Five tuned mass damper is used on single floor. Out of five, one is provided on center and other four is

provide at all four corner with proper distance from center (Figure 13).

Figure 13. Multiple tuned mass damper configuration

(a) b) (c) (d)

Figure 14. Four storey model with multiple tuned mass damper at various floor

Figure 12. Displacement response of Mass 1, Mass 2, Mass 3 and Mass 4 for TMD at different floor




Figure 15. Displacement response of Mass 1, Mass 2, Mass 3 and Mass 4 for MTMD at

different floor


Mass 4 for four storey building with multiple tuned mass damper. It is also derived from the Figure 15 that

building with multiple tuned mass damper at top floor shows maximum displacement response control.

Figure 16 shows comparison of time period of four storey building with TMD and MTMD. It is also derived

from the Figure 16 that multiple tuned mass damper at top floor shows maximum reduction in time period.

Figure 16. Comparison of time period for different building model with TMD and MTMD at

different floor




3. CONCLUSIONS

Experimental study is carried out for control dynamic response of four storey model using shear wall,

bracings, tuned mass damper (TMD) and multiple tuned mass damper (MTMD). Dynamic properties like

fundamental frequency, time period and displacement achieved for controlled building and compared with

uncontrolled building model by conducting experiment on shake table. Following conclusions may be drawn

from the experimental study:

Building model with four shear wall at all storey shows maximum reduction in time period as well as

displacement due to box effect and building model with shear wall at top storey showed increment in time

period and displacement because other three storey work as soft storey.

Building with V-type concentric bracing shows maximum increment in time period and double

inclined concentric bracing showed maximum decrement in time period as compared to other bracing system.

Cross inclined systems with bracings showed maximum reduction in displacement. Similarly, building with

eccentric bracing perform better than building with concentric bracings.

Building with tuned mass damper (TMD) and multiple tuned mass damper (MTMD) at top floor

shows maximum reduction in time period as well as displacement of building as compared to TMD and

MTMD at first floor, second floor and third floor.

REFERENCES

[1] Firoozabad ES, Dr. Rama MK, Bagheri RB2012, “Effect of shear wall configuration on seismic

performance of building”, Masters of technology thesis, JNTU Hyderabad, India.

[2] Handayani N, Kusumastuti D, and Rildova2008, “An Experimental Study on MTMD to improve

structural performance under dynamic loading”, 14th World Conference on Earthquake Engineering.

[3] Purohit SP, Panchal D2013, “Dynamic response control of a building model using bracings”, Procedia

Engineering, vol-51, pp. 266-273.

[4] Rana Rahul and Soong T. T. 1998, “Parametric study and simplified design of tuned mass dampers”,

Engineering Structures, vol. 20, pp. 193-204.

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Experimental Study of Multi Storey Building with Dynamic ...ijetmas.com/admin/resources/project/paper/f201704231492948899.pdfshear wall and tuned mass damper. A multi degree of freedom