A

PROJECT REPORT

ON

“MODELLING AND DRAFTING OF THE SUPPORT

COMPONENT OF A AIR FRAME IN A MISSILE”

Submitted in partial fulfillment of the requirement for

the award of degree of

BACHELOR OF TECHNOLOGY

IN

MECHANICAL ENGINEERING

SUBMITTED BY

SUSHANG SHAH - 105D1A03A4

Under the Esteemed Guidance of

Mr. R. SURENDRA RAO

(Asst. Professor, Mechanical Engineering Department)

DEPARTMENT OF MECHANICAL ENGINEERING

KASIREDDY NARAYAN REDDY COLLEGE OF ENGINEERING

& RESEARCH

(Affiliated to JNTUH, Hyderabad)

2010 – 2014

ACKNOWLEDGEMENT

A report work of this magnitude is not possible without the help of several

people directly or indirectly. It is with immense satisfaction that I present our practical

experience in the form of a project we carried out in RAMTECH

MANUFACTURING INDUSTRIES

I am grateful to Prof. Mr. S. AMARESH BABU, PRINCIPAL, KNRCER

for giving me the permission to carry out my project work at RAMTECH

ENGINEERING SERVICES.

I take this opportunity to thank Mr. D. MADHAV REDDY, Associate

Professor and Head of the Department of Mechanical Engineering for his

encouragement throughout the project work.

I wish to express my sincere and profound gratitude to Sri V.R.SUNIL

KUMAR, MD (RAM TECH Manufacturing Industries), Sri K.KISHORE KUMAR

REDDY, Design Engineer (RAM TECH Engineering Services), Sri M.SUNIL,

Master Technician (RAM TECH Manufacturing Industries) and M. MAHESH

KUMAR, project guide (RAM TECH Engineering Services), for guiding me and

providing valuable suggestions for the completion of my project.

I also express my sincere thanks to Mr. R. SURENDRA RAO, Assistant

Professor, Department of Mechanical Engineering for guiding me at every stage of

my project work.

SUSHANG SHAH -

105D1A03A4

CONTENTS

Abstract III

List of Figures IV

List of Tables V

1. INTRODUCTION 01 - 05

1.1 Methodology 01

1.2 Computer Aided Design (CAD) 02

1.3 Types of CAD software 03

1.4 Design process 04

2. INTRODUCTION TO UNIGRAPHICS 06 - 11

2.1 About UNIGRAPHIS 06

2.2 History of NX 07

2.3 NX 7.5 for design 07

2.4 NX 7.5 for manufacturing 08

2.5 NX 7.5 for simulation 09

2.5.1 NX 7.5 Nastran 10

2.6 Advantages 11

3. MISSILE 12 - 18

3.1 Types of missiles 12

3.1.1 Surface-Surface/Air-Surface 12

3.1.2 Surface-Air/Air-Air 13

3.2 Parts of missile 14

3.3 Use of coupler in different missiles 16

4. SUPPORT COMPONENT (TUBE COUPLER) 19 - 32

4.1 Introduction 19

4.2 Material used to manufacture 19

4.3 Drafting sheet of the component 21

4.4 Modeling of the object 23

5. CONCLUSION 33

6. REFERENCES 34

ABSTRACT

MODELLING AND DRAFTINGOF THE SUPPORT

COMPONENT OF A AIR FRAME IN A MISSILE

In manufacturing, the goal is to produce components that meet the design

specifications. The design specification ensures the functionality aspect. Next step to

follow is to assemble these components into final product. Process planning acts as a

bridge between design and manufacturing by translating design specification into

manufacturing process detail.

A missile is a self-propelled guided weapon system. Missiles have four system

components: targeting and/or guidance, flight system, engine, and warhead. Missiles

come in types adapted for different purposes: surface-to-surface and air-to-surface

(ballistic, cruise, anti-ship, anti-tank), surface-to-air (anti-aircraft and anti-ballistic),

air-to-air, and anti-satellite missiles.

Support is used to hold the air frame and other circuit parts in of a missile. Its

acts as a centre hanger or a tube coupler for a body tube and a launch lug of a missile.

The component is drafted and modeled using UNGRAPHICS (UGNX-7.5) by

Siemens

LIST OF FIGURES

Fig. No. Name Page No.

1.1 Design procedure cycle. 05

2.1 NX 7.5 cover 06

3.1 Parts of a missile. 14

3.2 Couple or support position outside of

the missile. 17

3.3 Support or tube coupler inside the missile. 17

4.1 Drafting sheet of the support component. 22

4.2 2D sketch of the section of the component. 23

4.3 Using revolve command. 24

4.4 Sketching a hole on the selected plane. 25

4.5 Making hole using extrude command. 26

4.6 It shows the holes at different angles. 27

4.7 Generated the holes at the given angles upto

some depth. 28

4.8 Making the counter sunk hole. 29

4.9 Chamfer on the outside edge of

the component on both sides. 30

4.10 Chamfer on the inside of the component. 31

4.11 Front view of the final product. 32

4.12 3D view of the component. 32

LIST OF TABLES:

Fig. No. Name Page No.

4.1 Wrought Al alloy composition limits(% weight). 20

4.2 Minimum tensile requirements for cast Al alloys. 20

ABSTRACT

MODELLING AND DRAFTING OF THE SUPPORT

COMPONENT OF AIR FRAME IN A MISSILE

In manufacturing, the goal is to produce components that meet the design

specifications. The design specification ensures the functionality aspect. Next step to

follow is to assemble these components into final product. Process planning acts as a

bridge between design and manufacturing by translating design specification into

manufacturing process detail.

A missile is a self-propelled guided weapon system. Missiles have four system

components: targeting and/or guidance, flight system, engine, and warhead. Missiles

come in types adapted for different purposes: surface-to-surface and air-to-surface

(ballistic, cruise, anti-ship, anti-tank), surface-to-air (anti-aircraft and anti-ballistic),

air-to-air, and anti-satellite missiles.

Support is used to hold the air frame and other circuit parts in of a missile. Its

acts as a centre hanger or a tube coupler for a body tube and a launch lug of a missile.

The component is drafted and modeled using UNGRAPHICS (UGNX-7.5) by

Siemens

1. INTRODUCTION

1.1 METHODOLOGY :

Process planning refers to the product design and decides how to manufacture it

within the resource constraints. Process planning can be seen as an activity which

integrates knowledge about products and resources.

Manufacturing process planning is the process of selecting and sequencing

manufacturing processes such that they achieve one or more goals and satisfy a set of

domain constraints.

Process planning is a production organization activity that transforms a product

design into a set of instruction (sequence, machine tool setup etc.) to manufacture

machined part economically and competitively. The information provided in design

includes dimensional specification (geometric shape and its feature) and technical

specification (tolerance, surface finish etc.)

My project deals with the drafting and modeling of “support” component using

CAM software (‘UGNX-7.5’ which is a CAD/CAM software used to generate part

program by designing and feeding the geometry of the component) and defining the

proper tool path and thus transferring the generated part program to the required CNC

machine with the help of DNC lines and manufactured. Then the program is executed

with suitable requirements.

The component can be either designed in UG or can be retrieved from any other

CAD software. Then sequence of programs such as modeling the component,

selection of tools according to the sequence of operations and sizes, generating the

tool path, at last the generated NC part program is verified and sent to the required

CNC machine to manufacture the particular component. Finally the required surface

finish has been obtained by machining the component at optimum speeds and feeds

and the cost of machining is also optimized by choosing optimal machining process

and machine tools.

1.2 COMPUTER AIDED DESIGN (CAD):

Today’s industries cannot survive worldwide competition unless they

introduce new products with better quality, at lower cost, and with shorter lead time.

Accordingly, they have tried to use the computer’s huge memory capacity, fast

processing speed, and user-friendly interactive graphics capabilities to automate and

tie together otherwise cumbersome and separate engineering or production tasks, thus

reducing the time and cost of product development and production. Computer-aided

design (CAD), computer-aided manufacturing (CAM), and computer-aided

engineering (CAE) are the technologies used for this purpose during the product

cycle. Thus, to understand the role of CAD, CAM, and CAE, we need to examine the

various activities and functions that must be accomplished in the design and

manufacture of a product.

Throughout the history of our industrial society, many inventions have been

patented and whole new technologies have evolved. Perhaps the single development

that has impacted manufacturing more quickly and significantly than any previous

technology is the digital computer. Computers are being used increasingly for both

design and detailing of engineering components in the drawing office.

Computer-aided design (CAD) is the use of computer technology for the

design of objects, real or virtual. CAD often involves more than just shape. As in the

manual drafting of technical and engineering drawings, the output of CAD often must

convey also symbolic information such as materials, processes, dimensions, and

tolerances, according to application-specific conventions.

The first step in preparing a process plan is to secure a good drawing or

drawings of the project. Because the drawings represent the initial ideas and plans for

the product, “The design of production processes starts with the product designer”

(Wright, 1990, p. 412). In many schools today, computer-aided drafting (CAD) is

taught and can be used to create the student’s ideas into quality, dimensioned

drawings with achievable specifications. Either manual or CAD drawings are suitable

as long as students know how to read and interpret them. The dimensioned drawings

should contain important information including the following: complete and clear

graphics, material types, part name, drawing number, owner name, date, units,

appropriate set of views showing all required dimensions, tolerances with reasonable

values for each dimension, clear titles and labels, and should be easy to read.

1.3 TYPES OF CAD SOFTWARES :

1. AUTOCAD : AutoCAD supports 2-D drafting and 3-D wire-frame models.

The system is designed as a single-user CAD package. The drawing elements

are lines, poly lines of any width, arcs, circles, faces, and solids. There are

many ways to define a drawing element. For example, a circle can be defined

by center and its radius, three points, and two end points of its diameter. The

system always prompts the user for all options.

2. PRO/E : Pro/Engineer is the software product of PTC (Parametric

Technology Corporation). Its initial versions were Pro/E 1,2…..upto 17. Later

Pro/E launched sequentially versions as Pro/Engineer 2000; 2000i; 2000i2;

2001; Wildfire 1.0; Wildfire 2.0; Wildfire 3.0; Wildfire 4.0; Wildfire 5.0. PTC

rebranded Pro/Engineer as Creo Parametric. It provides drafting, part

modeling and assembly modeling.

3. SOLIDWORKS : It is a 3D mechanical CAD program that runs on Microsoft

Windows and is being developed by Dassault Systems SolidWorks Corp., It is

currently used by over 2 million engineers and designers at more than 165,000

companies worldwide. It provides user to draft both 2D and 3D, assembly

modeling, flow simulation analysis, lofting.

4. SOLIDEDGE : Solid EGDE is a 3D CAD parametric feature solid modeling

software. It provides solid modeling, assembly modeling and drafting

functionality for mechanical engineers. It integrates with SharePoint and

teamcenter to provide product lifecycle management. It also integrates with

PLM products from third parties. Solid EGDE provides support for FEA

(Finite Element Analysis). This functionality is based on Siemens PLM’s

existing Femap and NX Nastran.

5. CATIA : CATIA (Computer Aided Three-dimensional Interactive

Application) is a multi platform CAD/CAM/CAE commercial software suite

developed by Dassault Systems written in the C++ programming language. It

can be applied to a wide variety of industries such as aerospace, defense,

automotive, shipbuilding, consumer goods, plant design, architecture and

construction.

6. UNIGRAPHICS NX : NX formerly known as NX Unigraphics or usually

just U-G is an advanced high-end CAD software package developed by

Siemens PLM software. It is used for design (parametric and solid/surface

modeling), engineering analysis (static, dynamic, electro-magnetic, thermal,

FEM and fluid using Sinite Volume Method).

1.4 DESIGN PROCESS :

1. Identifying problems and opportunities

2. Farming a design brief

3. Investigation and research

4. Generating alternative solutions

5. Choosing a solution

6. Select an approach

7. Development of design

8. Producing a prototype

9. Analysis and evaluating

10. Refining

11. Report

Fig. 1.1 Design procedure cycle.

2. INTRODUCTION TO UNIGRAPHICS

2.1 ABOUT UNIGRAPHICS :

NX, also known as NX Unigraphics or usually just U-G, is an advanced

CAD/CAM/CAE software package developed by Siemens PLM Software.

It is used, among other tasks, for:

Design (parametric and direct solid/surface modeling)

Engineering analysis (static, dynamic, electro-magnetic, thermal, using the

Finite Element Method, and fluid using the finite volume method).

Manufacturing finished design by using included machining modules.

Fig 2.1 NX 7.5 cover page

2.2 HISTORY OF NX :

First release of the new "Next Generation" version of Unigraphics and I-deas,

called NX. This will eventually bring the functionality and capabilities of both

Unigraphics and I-DEAS together into a single consolidated product.

Increasing complexity of products, development processes and design teams is

challenging companies to find new tools and methods to deliver greater innovation

and higher quality at lower cost. Leading-edge technology from Siemens PLM

software delivers greater power for today’s design challenge. From innovative

Synchronous Technology that unites parametric and history-free modeling, to NX

Active Mockup for multi-CAD assembly design, NX delivers breakthrough

technology that sets new standards for speed, performance, and ease of use.

NX automates and simplifies design by leveraging the product and process

knowledge that companies gain from experience and from industry best practices. It

includes tools that designers can use to capture knowledge to automated repetitive

tasks. The result is reduced cost and cycle time and improved quality.

2.3 NX 7.5 FOR DESIGN :

The release of NX 8.5 for Design extends the industry-leading modeling in NX to

dramatically reduce design time. For feature-based modeling, the new release includes

a more intuitive and efficient sketcher; feature creation using open profiles; and new

commands for sheet metal, draft, embossing, unite with region selection, and feature

grouping and coloring. The new capabilities accelerate modeling and significantly

reduce design steps and complexity as below.

1. Synchronous Technology :

Synchronous technology in NX 7.5 has been improved to more quickly

and easily modify multi-CAD geometry. When moving part faces, you can

now specify stepping and movement behavior to get the desired result quicker.

New tools enable you to select and delete blend surfaces, and to control how

geometry adapts and repairs.

2. Freeform Modeling :

For freeform modeling, NX 7.5 streamlines automotive class A surface

creation, improves design of engineered shapes from point data, and automates

curve and surface fitting to scanned or faceted geometry. New geometry

analysis tools improve validation for better aesthetics.

3. Drafting :

Enhanced drafting software in NX 7.5 provides new lightweight

drawing view tools that accelerate view creation and improve system

performance and memory usage for large assembly drawings. New drawing

booklets help you create and manage multiple files and drawing sheets that

comprise a complete set of assembly drawings.

4. Streamlined Workflows and User Experience :

NX 7.5 for Design offers an improved user experience and workflow

efficiencies that make NX easier to use, more readily discoverable, and more

productive. The user interface has been enhanced with “More” and “Less”

versions to balance interface simplicity with advanced capability. New

context-specific shortcut toolbars automatically present available actions for

any object you select in the graphics window or from the part or assembly

navigator. All improvements in the user interface accelerate design, increase

consistency and reduce training time.

2.4 NX 7.5 FOR MANUFACTURING :

With NX 7.5 for manufacturing, Siemens PLM software continues to help you

make the right product, right the first time. Enhancements across the solution set drive

productivity and quality improvements that make a difference to your business.

NX CAM increases NC programming productivity. It delivers the next level

of NC programming productivity with specialized, industry-specific capabilities in

NX CAM. New operation types and expanded feature-based automation simplifies the

creation of efficient tool paths for machinery and heavy equipment parts. You can

reduce excess machine motion for complex 5-axis turbine components with new

roughing and finishing operations, and eliminate extra machining steps for molds and

dies with new blended semi-finishing and finishing strategies.

Additionally, you can find tools faster and easily manage your complete

library of 3D cutting tool assemblies and manufacturing resources with the new

Manufacturing Resource Library. NX 7.5 for Manufacturing helps you maximize the

efficiency of your complete quality inspection process with the enhanced offline

programming and new inspection results analysis capabilities.

By working in the context of a 3D solid model environment to define scans

that include multiple features, you can program complex parts faster and more

accurately. Programming time can be reduced by as much as 80 percent by using PMI

(product and manufacturing information) on the model to automatically generate

programs. Using the enhanced 3D CMM simulation to verify and preview scans, you

can ensure programs are collision-free. You can also visualize the best approach to

improve part quality by analyzing CMM measurements directly on the 3D part in NX.

Find and use the optimum cutting tools for a job using the new Manufacturing

Resource Library to manage tooling vendor catalogs and preferred tool assemblies, as

well as your custom resources. You can also load the resources directly into NC

programs, machine tool simulations, and shop documentation.

2.5 NX 7.5 FOR SIMULATION :

With NX 7.5 for Simulation, Siemens PLM Software continues to invest in

developing new simulation technology that helps you create innovative products, and

engineer your products right. The result is over 240 new enhancements introduced in

the NX CAE 7.5 and NX Nastran 7.5 releases that help you optimize designs,

improve product durability and speed-up overall simulation processes.

NX CAE is a modern simulation environment for analysis modeling, as well as

structural, thermal, flow, motion, multiphysics and optimization analyses. NX CAE

8.5 introduces new capabilities in all of these areas, such as:

1. New NX Shape Optimization : Suggests specific, detailed improvements to

an existing design to reduce stress concentrations.

2. FE model in-context : Capability speeds-up finite element assembly

modeling by allowing you to see and reference the rest of the assembly while

editing a FE component model.

3. Thermal solver multi-threading : Takes advantage of multi-core and multi-

processor hardware to speed up thermal computations.

4. Durability analysis from flexible body motion simulation : Helps you

better understand component performance and extend product life.

2.5.1 NX 7.5 Nastran :

Available either as a standalone solver or integrated in NX CAE, NX Nastran

is the premier FEA solver for computational performance, accuracy, reliability and

scalability. NX Nastran 7.5 introduces numerous enhancements, such as:

1. Edge-to-edge glue and contact definitions : Allows you to easily join shell

meshes which are dissimilar.

2. Bolt pre-loads on solid elements : Give you a more detailed representation of

bolts, including contact between hole and bolt.

3. Rotor dynamics bearing definition : Supports speed-dependent, asymmetric

stiffness and viscous damping.

2.6 ADVANTAGES :

NX is the industry’s most integrated, flexible and efficient solution for product

design, engineering and manufacturing.

1. No other solution employs synchronous technology for flexible design in an

open environment

2. No other solution integrates multi-discipline simulation so tightly into the

development process

3. No other solution offers such a full range of advanced part manufacturing

applications

4. No other solution is integrated as tightly with Team center, the world’s leading

Product Lifecycle Management (PLM) platform

3.MISSILES

A missile is a self-propelled guided weapon system, as opposed to an

unguided self-propelled munition, referred to as just a rocket. Missiles have four

system components: targeting and/or guidance, flight system, engine, and warhead.

Missiles come in types adapted for different purposes: surface-to-surface and air-to-

surface missiles (ballistic, cruise, anti-ship, anti-tank, etc.), surface-to-air missiles

(anti-aircraft and anti-ballistic), air-to-air missiles, and anti-satellite missiles. All

known existing missiles are designed to be propelled during powered flight by

chemical reactions inside a rocket engine, jet engine, or other type of engine.[citation

needed] Non-self-propelled airborne explosive devices are generally referred to as

shells and usually have a shorter range than missiles. The word missile comes from

the Latin verb mittere, meaning "to send".

3.1 TYPES OF MISSILES :

Missiles are be surface (ground or water generally categorized by their launch

platform and intended target. In broadest terms, these will either) or air, and then sub-

categorized by range and the exact target type (such as anti-tank or anti-ship). Many

weapons are designed to be launched from both surface or the air, and a few are

designed to attack either surface or air targets. Most weapons require some

modification in order to be launched from the air or surface, such as adding

boosters to the surface-launched version.

3.1.1.Surface-surface/Air-surface:

This type of missile are used to demolish the ground targets such as tanks,

buildings, enemy base etc., Ballistic, cruise missile, Anti-Ship, Anti-Tank are the few

examples of the missiles targeted towards ground from a distance or from the air.

a)Ballistic : Ballistic missiles are largely used for land attack missions. Although

normally associated with nuclear weapons, some conventionally armed ballistic

missiles are in service, such as ATACMS The V2 had demonstrated that a ballistic

missile could deliver a warhead to a target city with no possibility of interception, and

the introduction of nuclear weapons meant it could efficiently do damage when it

arrived. Today the ballistic missile represents the only strategic deterrent in most

military forces, however some ballistic missiles are being adapted for conventional

roles.

b)Cruise missile : Cruise missiles are generally associated with land attack

operations, but also have an important role as anti-shipping weapons. They are

primarily launched from air, sea or submarine platforms in both roles, although land

based launchers also exist. The BRAHMOS is a cruise missile which is a joint

venture between India and Russia.

c)Anti-Ship : It is a type of cruise missile used to destroy the target in marine such as

ships, sub marines. It is also knows as “Sea Skimmers”. A number of anti-submarine

missiles also exist; these generally use the missile in order to deliver another weapon

system such as a torpedo or depth charge to the location of the submarine, at which

point the other weapon will conduct the underwater phase of the mission.

d)Anti-Tank : Anti tank missiles may be launched from aircraft, vehicles or by

ground troops in the case of smaller weapons. This missile is used to destroy the

enemies troops, tanks, near targets.

3.1.2.Surface-Air/Air-Air:

This type of missiles are used to destroy the enemy flying in air either by

launching the missile from the ground or targeting it from the plane. Anti-Aircraft,

Anti-Ballistic, Anti-Satellite are the few types of this type of missile.

a)Anti-Aircratf : Anti-aircraft weapons exist for virtually every possible launch

platform, with surface-launched systems ranging from huge, self-propelled or ship-

mounted launchers to man portable systems.

b)Anti-Satellite : Anti satellite weapons may be launched either by an aircraft or a

surface platform, depending on the design. To date, only a few known tests have

occurred.

c)Air-Air : Air to Air missiles also have a wide range of sizes, ranging from

helicopter launched self-defense weapons with a range of a few km, to long range

weapons designed for interceptor aircraft such as the Vmypel R-37.

3.2 PARTS OF MISSILE :

The parts that are required on missile and plan are listed below. To become

familiar with them and their function label them on your plan/drawing. The missile

have many parts which are assembled together. Every section has its own role to play,

hence with the help of the fig 3.1 some of the important parts and their roles have

been explained below.

Fig 3.1 Parts of a missile.

1. Nose Cone : Aerodynamically designed to provide a smooth flow of air

around the rocket body. It gives the rocket a streamlined shape for lower

drag. Usually made of plastic or balsa.

2. Payload section : A section used on some models to carry

instrumentation, weight, biological specimens etc. Its also a optional part

of rocket allowing to fly payloads.

3. Transistor or Adaptor : connects parts of the airframe with different

diameters.

4. Parachute : A thin plastic or cloth chute used to slow the descent of the

rocket. sometimes replaced by a streamer or other recovery device.

5. Shock Cord : Elastic cord to prevent the strong ejection charge from

damaging the noce cone.

6. Wadding : Insures that the parachute will be properly ejected and protects

the chute from the heat of the ejection charge. It protects the parachute

from the hot gases ejected from engine.

7. Body Tube : The basic structural unit of the rocket- determines the design

and function of all other parts of the rocket.

8. Engine Ring : Glued inside the body tube to hold the engine in the proper

position and to absorb the thrust of the engine.

9. Fins : Guide the rocket on a straight flight and gives the essential stability

for true flight.

10. Launch Lug : A thin tube which guides the rocket on the launch rod until

sufficient speed has been reached for the fins to become effective.

11. Engine : A solid propellant contained in a sturdy casing.

12. Engine Mount : The part inside which the engine of the missile is

mounted. Made of high-strength phenolic tubing. It is essentially heat

proof. Variety of lengths and diameters are available. Wide verity of

centering rings to fit MMTs in any air frame.

13. Tube Coupler : Acts as a joint between body tube and launch lug.

3.3 USE OF COUPLER IN DIFFERENT MISSILES :

The support or the coupler is used in missiles either to hold the

electrical inside the missile or to join the body with engine from outside.

Fig 3.2 Couple or support position outside of the missile.

The above fig 3.2 shows the position of the support or the coupler

which acts as the hub for the air frame and the launch lug. The part which is

highlighted in green is the support component and the other parts are in different

colors like the part represented in red are fins, air frame is shown in yellow, parachute

is represented with the white and orange stripes, the launch lug is represented in

brown and the nose is in blue.

Fig 3.3 Support or tube coupler inside the missile.

The fig 3.3 shows the coupled placed inside the missile air frame to hold the

electrical inside the missile. It also holds the launcher of the parachute such that when

the upper portion is ejected the parachute still fixed to the coupled.

Usually the missiles which are used for surface-surface or air-surface used the

coupler inside of the air frame as shown in fig 3.3 and the missiles which are used for

surface-air uses the support component outside of the missile as shown in fig 3.2. The

missiles used for air-air or air-marine uses both the couplers either outside or inside or

both at a time depending on the size, shape and the amount of explosives it carries.

4. SUPPORT COMPONENT (TUBE COUPLER)

4.1 INTRODUCTION :

A support component also known as a tube coupler, is used to hold the air-

frame and other circuits and launch lug of a missile. It as a joint for the missile to

connect the air frame with launch lug more rigidly and tightly. Thus the component is

designed in such a way that it could withstand the loads and forces acting on it.

In flight, a rocket is subjected to four forces; weight, thrust, lift and drag. The

magnitude of the weight depends on the mass of all of the parts of the rocket. The

weight force is always directed towards the centre of the earth and acts through the

centre of gravity. The magnitude of the thrust on the mass flow rate through the

engine and the velocity and pressure at the exit of the nozzle. The thrust force

normally acts along the longitudinal axis of the rocket and therefore acts through the

centre of gravity. The resulting torque about the centre of gravity can be used to

maneuver the rocket. The magnitude of the aerodynamic forces depends on the shape,

size, and velocity of the rocket, properties of the atmosphere. The aerodynamic forces

act through the centre of pressure.

4.2 MATERIAL USED TO MANUFACTURE :

Generally to this component is manufactured of aluminium alloy, in which

aluminium (Al) is the predominant metal. The typical alloying elements are

copper, magnesium, manganese, silicon and zinc.

There are two principal classifications, namely casting alloys and wrought

alloys, both of which are further subdivided into the categories heat-treatable and non-

heat-treatable. About 85% of aluminium is used for wrought products, for example

rolled plate, foils and extrusions. Cast aluminium alloys yield cost-effective products

due to the low melting point, although they generally have lower tensile strengths than

wrought alloys. Aluminium alloys are widely used in engineering structures and

components where light weight or corrosion resistance is required.

Aluminium alloy compositions are registered with the aluminium associations.

Many organizations publish more specific standards for the manufacture of

aluminium alloy, including the SOCIETY OF AUTOMOTIVE

ENGINEERS(SAE) standards organization, specifically its aerospace standards

subgroups, and ASTM International.

TABLES :

Allo

y

Si Fe Cu Mn Mg Cr Zn Ti Limits+

+

Al

2014 0.50

-1.2

0.7 3.9

-

5.0

0.40

-1.2

0.20

-0.8

0.1

0

0.2

5

0.1

5

0.15 remainin

g

2024 0.50 0.5

0

3.8

-

4.9

0.30

-0.9

1.2-

1.8

0.1

0

0.2

5

0.1

5

0.15 remainin

g

Table 4.1 Wrought Al alloy composition limits (% weight)

Alloy type

Tempe

r

Tensile strength

(min) [ksi] ([MPa])

Yield strength

(min) [ksi]

([MPa])

Elongation in 2

in [%]

ANSI UNS

201.0 A0201

0 T7 60.0 (414) 50.0 (345) 3.0

Table 4.2 Minimum tensile requirements for cast Al alloys

The above table 4.1 showcases the standard Al alloy composition for the

support component. Mostly 2014 alloy composition is used for the couplers which are

outside of the missile to support rigid fix of air-frame and the launch lug and the 2024

alloy composition is used for the missiles having a coupler inside of air-frame to hold

the electrical circuits and wires and even parachute in some cases.

Since the material has to withstand high forces acting on it during the flight,

the Al alloy of 2014 is used in our support component. The table 4.2 represents the

strength of the alloy when the forces acting on it.

Aluminium alloy 2024 is an aluminium alloy with copper as the primary

alloying element. It is used in application requiring high strength to weight ratio, as

well as good fatigue resistance. It is weldable only through friction welding, and has

average machinability. Due to poor corrosion resistance, it is often clad with

aluminium 05 al-lzn for protection, although this may reduce the fatigue strength.

Aluminium alloy 2024 has a density of 2.78 g/cm³ (0.1 lb/in³), electrical

conductivity of 30% IACS, young's modulus of 73 GPa (10.6 Msi) across all tempers,

and begins to melt at 500 °C (932 °F). 2024 aluminium alloy's composition roughly

includes 4.3-4.5% copper, 0.5-0.6% manganese, 1.3-1.5% magnesium and less than a

half a percent of silicon, zinc, nickel, chromium, lead and bismuth.

Due to its high strength and fatigue resistance, 2024 is widely used in aircraft

structures, especially wing and fuselage structures under tension. Additionally, since

the material is susceptible to thermal shock, 2024 is used in qualification of liquid

penetrate tests outside of normal temperature ranges

4.3 DRAFTING SHEET OF THE COMPONENT :

The below shown drafting sheet of the support component doesn’t have the

exact dimensions as the original prototype of the missile. Various modifications were

made, since the design of it is highly confidential. The holes shown in the design are

also dislocated. Although the design and concept of the support remains unchanged.

Fig 4.1 Drafting sheet of the support component.

The fig 4.1 shows the drafting sheet of the object. The object has to be

designed as per the dimensions mentioned in the drafting sheet. The amount of depth

of the cuts and the amount of chamfering which is to be given for the object is also

mentioned in this sheet

4.4 MODELING OF THE OBJECT :

The step by step procedure for the modeling of the support component is

represented in the fig. below.

Fig 4.2 2D sketch of the section of the component.

The above fig 4.2 shows the diagram of the sectional part of the support

component. Firstly select the front plane such that the screen sets to the XY plane.

Now sketch the sectional part as shown in the fig 4.2.

Fig 4.3 Using revolve command.

Above the revolve command is used to generate the 3D view of the component. Here

the sectional part which was sketched is revolved at the X-axis. Hence the 2D

sectional sketch is generated into the 3D and shows the shape of the component.

Fig 4.4 Sketching a hole on the selected plane.

Now a datum plane is selected on the surface where the hole has to be made.

After the plane is selected the object automatically turns to the phase where the hole

has to be sketched. Now by using the circle command we sketch the hole at the

position shown in the drafting sheet as shown in fig 4.4.

Fig 4.5 Making hole using extrude command.

The hole which was sketched in the fig 4.4 is made with the help of extrude

function as shown in the fig 4.5. These holes acts as an reference to the rest of the

holes and even for the connection of the air frame to it. The holes are extrude cut upto

the length of 1.625 mm as shown in fig 4.5.

Fig 4.6 It shows the holes at different angles.

Again select the front plane on the screen such that the holes on different

angles can be made as shown in fig 4.6. These holes acts as an attachment of the

launch lug. The launch lug having the extended tube like structures which are inserted

into these holes to attach the support with it. The above fig 4.6 shows only the sketch

of the holes on the surface which is selected.

Fig 4.7 Generated the holes at the given angles upto some depth.

Now with the help of extrude cut command, the holes which were sketched on

the surface are made. The above fig 4.7 demonstrates the holes made at desired angles

around the inside surface of the support component. The holes are similar in

dimensions say 2.36 mm and the depth given to the object is 11.825 mm. by selecting

the subtract option in the Boolean the sketches which are extruded will form a cut and

the amount of material represented in orange in fig 4.7 will be removed forming the

holes.

Fig 4.8 Making the counter sunk hole.

The counter sunk holes are made on the one side of the object say 90 degrees

left. Now by using the mirror feature, the hole made is mirrored on the opposite side

of the object. This hole is made to hold the arming key such that it ensure the

complete locking of the support to the air frame.

This hole may or may not be exist in many missiles as it is very typical and

may produce additional drag to the missile when the locking key is fixed. Instead of

the locking key the support is given internal threading to hold the air frame from

inside.

Fig 4.9 Chamfer on the outside edge of the component on both sides.

The above fig 4.9 represents the chamfering operation on the outside edge of

the object. With the use of chamfering command, the distance of 0.5 mm at 45

degrees angles is chamfered. This command is given to make the smooth surface edge

instead of a sharp edge.

Fig 4.10 Chamfer on the inside of the component.

Now select the datum plane at the centre of the object as shown in the fig 4.10.

The object is chamfered again on the surface of the datum plane to obtain a smooth

cylindrical surface. The orange surface which is highlighted in the fig 4.10 represents

the inner chamfered surface. The same amount of chamfering is to be given at the

other side of the object where the launch lug is to be connected.

Fig. 4.11 Front view of the final product.

Fig. 4.12 3D view of the component.

5. CONCLUSION

The support component is designed in the software with the same dimensions

which are marked on the drafting sheet. With more research and development on the

product, we can develop more high strength component which can be used for navy

missiles for the Indian army. Thus the fig 4.11 shows the front view of the final object

obtained and the fig 4.12 shows the 3D view of the final object.

Hence the drafting and modeling of the support component is completed

successfully on the CAD based NX UniGraphics 7.5. The object is ready to undergo

manufacturing process in RAMTECH ENGINEERING SERVICEs.

The support is manufactured on the 4-axis milling machine in which all the

steps taken to design the product in software are followed in a step-by-step. After the

manufacturing of the support component it is given for an inspection where the

technician analyses the product and compares it with the already built replica of the

support component.

If the product matches all the design dimensions with the tolerance limit than

it is sent for the packing and loaded to the next station where the support component

is ready to fix lunch lug with the air frame of a missile which is developed by the

DRDO for the Indian air force.

REFERENCES

1. Fundamentals of rockets and missiles – Edward L. Keith

2. "Astra BVRAAM more complex than Agni missiles".Domain-B (Balasore).

31 August 1998. Retrieved 31 May 2012.

3. "DRDO: Historical Background". Retrieved 31 May 2012.

4. "Missile programme scrapped". Chennai, India: The Hindu News Update

Service. 9 January 2008. Retrieved 12 September 2013.

5. Space and Missile Defense Command -

http://www.smdc.army.mil/FactSheets/SBMDF.pdf

6. http://en.wikipedia.org/wiki/Missile

7. Datasheets - Aluminium Alloy - BS-L - L168 T6511 - 2014A Bar | Wilsons

Ltd

8. http://www.suppliersonline.com/propertypages/2014.asp

9. http://www.mikalac.com/mis/missile.html

10. http://drdo.gov.in/drdo/data/Guided%20Missiles.pdf