1

ABSTRACT

In any automobile the power is transmitted from one shaft to another by

using chain sprocket assembly. Chain assembly consists of chain,

driving sprocket and driven sprocket. The driving sprocket is connected

to engine output shaft, which transfer power to driven sprocket by chain.

Further this driven sprocket transfer power to drive shaft. The material

used for driving sprocket is mild steel. The design of this sprocket plays a

vital role in efficient running of the automobile. Because of this reason

careful efforts are required in design chain sprocket.

In this project a two wheeler automobile chain sprocket is designed and

detailed finite element analysis is carried out to calculate stresses and

deflections on the sprocket. Later the analysis is extended to fatigue

analysis to estimate the life of the chain sprocket. Initially, the 3D model

of the chain sprocket is done from design obtained from previous

literatures. Finite element analysis is carried out by applying the forces

evaluated from the calculations. From the analysis principle stresses are

calculated and are used as fatigue inputs for making Goodman diagram.

NX-CAD software is used for doing 3D model and Ansys is used for doing

finite element analysis.

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1.INTRODUCTION

A chain is a reliable machine component, which transmits power by

means of tensile forces, and it used primarily for power transmission.

The function and uses of chain are similar to a belt, Roller chain or bush

roller chain is the type of chain drive most commonly used for

transmission of mechanical power on many kinds of domestic, industrial

and agricultural machinery, including conveyors, cars, motorcycles, and

bicycles. It consists of a series of short cylindrical rollers held together by

side links. It is driven by a toothed wheel called a sprocket. It is a simple,

reliable, and efficient means of power transmission. Two different sizes of

roller chain showing construction. There are actually two types of links

alternating in the bush roller chain. The first type is inner links, having

two inner plates held together by two sleeves or bushings upon which

rotate two rollers. Inner links alternate with the second type, the outer

links, consisting of two outer plates held together by pins passing

through the bushings of the inner links. The "bushing less" roller chain

is similar in operation though not in construction; instead of separate

bushings or sleeves holding the inner plates together, the plate has a

tube stamped into it protruding from the hole which serves the same

purpose. This has the advantage of removing one step in assembly of the

chain [1].The roller chain design reduces friction compared to simpler

designs, resulting in higher efficiency and less wear. The original power
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transmission chain varieties lacked rollers and bushings, with both the

inner and outer plates held by pins which directly contacts with the

sprocket teeth however this configuration exhibited extremely rapid wear

of both the sprocket teeth, and the plates where they pivoted on the pins.

This problem was partially solved by the development of bushed chains,

with the pins holding the outer plates passing through bushings or

sleeves connecting the inner plates. The addition of rollers surrounding

the bushing sleeves of the chain and provided rolling contact with the

teeth of the sprockets resulting in excellent resistance to wear of both

sprockets and chain. Roller chains are of primary importance for efficient

operation as well as correct tensioning

In many areas, especially urban areas, parking is a serious problem.

Shortages of parking space, complaints about high parking tariffs and

congestion due to visitors in search for a parking place are only a few

examples of everyday parking problems. Many cities and urban areas

recognize these problems, but the solution proves to be very complicated.

Delhi, the capital of India is facing an acute transport management

problem. This primary problem leads to many more secondary problems

such as air pollution, high-energy consumption, congestion, loss of

productivity, increase in death accident rates etc.

Roller chain or bush roller chain is one of the type of chain drive mostly

used for transmission of mechanical power on many kinds of domestic,

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industrial, agricultural machineries, as well as includes conveyor and

tube-drawing machines, printing presses, cars, motorcycles, and bicycles

etc. Chain drive consists of a series of short cylindrical rollers held

together by side links. Chain drive is driven by a toothed wheel called a

sprocket.

A sprocket-wheel or sprocket is a profiled wheel with teeth, cogs that

mesh with a Chain. The name 'sprocket' is applies generally to any wheel

upon which radial projections engages a chain passing over it. Sprockets

are used in bicycle, motorcycle, car tracked wheel, and other machinery

either to transmit rotary motion between two shafts where gears are

unsuitable or to impart linear motion to a track, tape. Sprockets are of

various in designs, a maximum of efficiency being claimed for each by its

designer. Sprockets typically do not have a flange. Some sprockets used

with timing belt have flanges to keep the timing belt centre aligned.

Sprockets and chains are also used for power transmission from one

shaft to another where slipping of chain is not admissible, sprocket

chains being used instead of belts or ropes and sprocket-wheels instead

of pulleys. They can be run at high speed and some forms of chain are so

constructed as to be noiseless even at high speed. Chain sprocket has

problems like braking of bushings and/or rollers, braking of plates and

pins (unusual cracks), quickly wear of sprockets, Worn rollers, etc.

Possible causes of these problems are significant overload breakage, high

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impact pressure, excessive chain wear far beyond replacement level,

combination of worn chain with new sprockets etc.

In this paper it is proposed to substitute the metallic sprocket of

motorcycle with composite material to reduce the weight and noise. For

the purpose composite material were considered namely carbon fibre and

the irritability are checked with their counterpart metallic gear(Mild

steel). Based on the static analysis, the best composite material is

recommended for the purpose. A virtual model of sprocket was created in

NX-CAD. Model is imported in Hyper mesh 12. 0f or pre-processing and

analysis is carried in ANSYS 13 After analysis a comparison is made

among existing mild steel sprocket. Based on the deflections and stresses

from the analysis, we choose carbon fibre as a substitute of metal.

No researcher has applied effort for designing of sprocket with carbon

fibre. Therefore, there is stern need to work on sprocket with composite

material. In this work, we introduced the carbon fibre as replacement for

conventional mild steel. Also we done the CAD through reverse

engineering and analysis is carried out using Hyper mesh and ANSYS

In designing, building and discussing chain drive systems it is

important to understand the concepts and terminology associated with

chain drive systems. The design of a chain drive demands the

requirements of load, and description of driver and driven speeds and

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their units along with peak load, center distance and operating

conditions. Elongations due to wearing of chain can be neglected at a

speed of 50m/min. For high shock loads the Service factor used for

chain drives ranges up to 1.7. Pitch selection tables are used for

selection of proper pitch, which is also used for synchronous belts.

Numbers of strands required are determined from rating tables, once the

sprocket sizes have been chosen. Many chain drive industries admitted

that most chain drives are not designed properly. Without having all the

basic drive data, Poly Chain belt drives are not supposed to be designed

only on the basis of chain rating information. This study provides design

calculation of chain drive in detail. Chain drives are similar to belt

drives, for essential satisfactory performance; proper tension is required

.This tension in chain is related to chain sag which is known as the

catenary effect" It is a curve (catenary effect) made by a cord (chain or

cable) of uniform weight suspended between two points. Sag is a

phenomenon which usually occurs in chain drive which can be defined

as a bend or hang down in the middle especially because of weight or

weakness. The apron feeder, an essential part of mobile crushing station,

typically adopts chain drive system to offer transmission. As an executive

component, the chain drive system is prone to encounter fatigue and

vibration damage
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In recent years, scholars have conducted a wide range of studies on

chain drive and made progress in many fields. In, the empirical formula

of tight-side stress is proposed through a series of experiments. In ,

taking the elastic deformation and dead load of chain roller into account,

the mechanical model is built on the basis of the standard tooth profile,

and the dead load of tension distribution curve is calculated through

Newton-Raphson method. In the multi-body dynamics models of chain

drive in large commercial diesel engine are established for analysis and

prove that the model with a real tooth profile proves superior to the one

with a circular profile. The impulsive load calculation formula for chain

drive system is derived and indicates that the impulsive force between

rollers and sprocket tooth is a periodic pulse force which is prone to

cause the fatigue failure of rollers. In the paper regards the roller chain

as a rigid polygon and reveals some certain reasons that cause the

locking phenomenon. In summary, the existing references

comprehensively involve the analyses of dynamics, the load distribution

the meshing impact, the polygonal action and the method of reducing the

vibration. However, few researchers specifically explain the relationship

between design parameters and the speed fluctuation of roller chain, and

there are scarce analyses which are carried out in the case of low speed

and heavy intermittent external impulsive load. Therefore, this paper,

concentrating on the typical working condition of mobile crushing

station, conducts an array of theoretical analyses and contrasts

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analytical results with simulation ones. These works strive to provide

support in the design of chain drive system in a heavy duty apron feeder

of mobile crushing station.

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2. LITERATURE REVIEW

Mr. Nikhil S. Pisal, Prof. V.J. Khot , published a paper on

STRUCTURAL ANALYSIS OF MOTORCYCLE CHAIN BY USING C.A.E.

SOFTWARE. The abstract of the paper is Any catastrophic failure in

the chain used in power transmission of a motorcycle could lead to a

safety hazard. Determining safe load for the chain and the ability of the

same to withstand the using Finite Element Modelling would be the core

objective of this work. An existing chain link would be used for

benchmarking the research work. Finite Element Analysis tools like

Hyper Mesh and ANSYS are suitable to find the performance of the link

under tensile loads. Recommendation over the best suited geometry or

material would be presented to conclude the work.

RamNath YadavPP, NiteshKumar VarshneyPP, Manish MaviP,

Published a paper on. Design and Analysis of Shaft and Sprocket for

Power Transmission Assembly. The abstract of the paper is There is a

rapid increase in automobiles all over the world. The net result is a lack

of parking space. This is a problem that is faced by everyone in day to

day life. Thus, our project deals with this problem and therefore, I

suggest few measures that could be helpful in overcoming this problem.

The present research paper emphasizes upon design and analysis of

shaft and sprocket for power transmission assembly of vehicle for

parking purpose. Two components were designed for giving transverse

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movement to the vehicle namely sprocket and shaft. After identifying the

components, a 3-d model was created in solid works. Then load and

boundary condition was applied and analytical designing was done. By

adding these components in 3-d model of the existing system, it is found

that the whole system is safe and can work practically. By designing the

system and assembling it, we conclude that transverse movement of

vehicle is essential for parallel parking.

Nikhil P. Ambole1, Prof. P. R. Kale, Published a paper on A

Review on Carbon Fiber Sprocket Design Analysis and Experimental

Validation. The abstract of the paper is Roller chain or bush roller

chain is the type of chain drive most commonly used for transmission of

mechanical power on many kinds of domestic, industrial and

agricultural machinery, conveyor bicycles, cars and tube drawing

machines, motorcycles, and printing presses. It consists of a series of

short cylindrical rollers held together by side links. It is driven by a

toothed wheel called a sprocket. We see there are some common

problems that might occur when using a sprocket chain like broken

bush, pins, sprockets etc. In our project, we are going to model a

sprocket chain in 3Dmodeling software (NX-CAD), meshing will be done

in Hyper mesh and for post processing we will use Ansys. A sprocket

chain will be manufactured with carbon fibre material. Testing will be

carried to validate the results between numerical and analytical model.

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Parag Nikam, Rahul Tanpure, Published a paper on Design

Optimization Of Chain Sprocket Using Finite Element Analysis. The

abstract of the paper is Chain sprocket is one of the important

component of chain drive for transmitting power from one shaft to

another. To ensure efficient power transmission chain sprocket should

be properly designed and manufactured. There is a possibility of weight

reduction in chain drive sprocket. In this study, chain sprocket is

designed and analysed using Finite Element Analysis for safety and

reliability. ANSYS software is used for static and fatigue analysis of

sprocket design. Using these results optimization of sprocket for weight

reduction has been done. As sprocket undergo vibration, modal analysis

is performed.

Nikhil P. Ambole, Prof. P. R. Kale, Published a paper on Design

and Analysis of Carbon Fiber Sprocket. The abstract of the paper is

The sprocket is a very essential part in the transmission of power and

motion in most motorcycles. Generally sprockets are made of mild steel.

In this paper, existing sprocket motorcycle is compared with the

sprocket of carbon fibre material. The drawing and drafting is done using

CAD software. Further FEA software are used for analysis of sprocket

chain. With different properties of mild steel and carbon fibre, stress and

deformation of sprocket is compared. This work will be useful for further

development of sprockets chain.

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M. Ravi Teja Reddy, C. Sai Virinchy, T.S.A. Surya kumari,

Published a paper on Design and analysis of chain drive for different

materials and load conditions . The abstract of the paper is As of

today, over 0.2 billion two wheelers are being used across the world. One

of the important components for the power transmission that is an

integral part of all two wheelers is the chain drive. The amount of torque

that the chain drive delivers is the important determining factor for

speed, acceleration and performance of a two wheeler. The present work

is aimed at designing and analysis required to decide the capacity of a

chain drive that should be used to drive a vehicle of particular

specifications. Structural analysis was carried out for Chain links of

different materials Aluminium 7475-T761alloy and Stainless steel.

Stainless steel resulted as with less stress distribution and depending

upon the stress acting on the Chain link, corresponding dimensions were

determined.

JunzhouHuo, Shiqiang Yu, Jing Yang and Tao Li, Published a

paper on Static and Dynamic Characteristics of the Chain Drive

System of a Heavy Duty Apron Feeder. The abstract of the paper is

Mechanical models of a chain drive system are proposed and applied to

the theoretical analysis of chain drive system of a certain type of heavy

duty apron feeder in mobile crushing station, including a five-bar model

discussing the speed fluctuation problems of the chain drive system, an

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elastic collision model probing the effects of impulsive loads anda model

of meshing area revealing the stress of chain links.

Theoretical analysis indicates that the teeth number and sprocket

pitch have the most influential effect on the vibration in the conveying

direction; external impulsive loads are caused a significant increment of

chain force, especially when loads caused by large materials; the initial

pressure angle affects the roller chain stress conditions immensely.

Then, multi-body dynamics models are established for the verification of

theoretical results and dynamic simulation. Simulation results are in

good agreement with the theoretical results and illustrate that impulsive

loads affect chain tension significantly.

Nikhil P. Ambole and Pravin R. Kale, Published a paper on

Carbon Fiber Sprocket: Finite Element Analysis and Experimental

Validation. The abstract of the paper is The sprocket is a very

essential part in the transmission of power and motion in most

motorcycles. Generally sprockets are made of mild steel. In this paper,

existing sprocket motorcycle is compared with the sprocket of carbon

fiber material. The drawing and drafting is done using CAD software.

Further FEA software is used for analysis of sprocket chain. With

different properties of mild steel and carbon fiber, stress and deformation

of sprocket is compared. This work will be useful for further development

of sprockets chain.
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3. PROBLEM DEFINITION & METHODOLOGY

In this project a two wheeler automobile (PULSAR BIKE) chain sprocket

is designed BY REVERSE ENGINEERING using NX-CAD software.3d

model and 2D engineering data and has been developed using NX-CAD.

Structural static analysis is carried out to calculate stresses and

deflections on the sprocket by applying boundary conditions and loading.

From the analysis principle stresses are calculated and are used as

fatigue inputs for making Goodman diagram

Dimensions of pulsar bike sprocket are taken by reverse engineering

using measuring instruments like vernier and scale.

3d model and 2D engineering data and has been developed using NX-

CAD.3D model is converted into parasolid to import into Ansys.

Structural static analysis is carried out to calculate stresses and

deflections on the sprocket by applying boundary conditions and

loading.

From the analysis principle stresses are calculated and are used as

fatigue inputs for making Goodman diagram

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3.1. INTRODUCTION TO NX-CAD

Overview of Solid Modeling

The Uni-graphics Modeling application provides a solid modeling

system to enable rapid conceptual design. Engineers can incorporate

their requirements and design restrictions by defining mathematical

relationships between different parts of the design.

Design engineers can quickly perform conceptual and detailed

designs using the Modeling feature and constraint based solid modeler.

They can create and edit complex, realistic, solid models interactively,

and with far less effort than more traditional wire frame and solid based

systems. Feature Based solid modeling and editing capabilities allow

designers to change and update solid bodies by directly editing the

dimensions of a solid feature and/or by using other geometric editing

and construction techniques.

Advantages of Solid Modeling

Solid Modeling raises the level of expression so that designs can be

defined in terms of engineering features, rather than lower-level CAD

geometry. Features are parametrically defined for dimension-driven

editing based on size and position.

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Features

Powerful built-in engineering-oriented form features-revolve, holes,

extrudes, ribs, sweep, sweft blend, cuts-capture design intent and

increase productivity.

Patterns of feature instances-rectangular and circular arrays-with

displacement of individual features; all features in the pattern are

associated with the master feature

Blending and Chamfering

zero radius

Ability to chamfer any edge

Cliff-edge blends for designs that cannot accommodate complete

blend radius but still require blends

Advanced Modeling Operations

Profiles can be swept, extruded or revolved to form solids

Extremely powerful hollow body command turns solids into thin-

walled designs in seconds; inner wall topology will differ from the

outer wall, if necessary

Fixed and variable radius blends may overlap surrounding faces and

extend to a Tapering for modeling manufactured near-net shape parts

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User-defined features for common design elements (Uni-

graphics/User-Defined Features is required to define them in

advance)

3.1 General Operation

Start with a Sketch

Use the Sketcher to freehand a sketch, and dimension an "outline" of

Curves. You can then sweep the sketch using Extruded Body or Revolved

Body to create a solid or sheet body. You can later refine the sketch to

precisely represent the object of interest by editing the dimensions and

by creating relationships between geometric objects. Editing a dimension

of the sketch not only modifies the geometry of the sketch, but also the

body created from the sketch.

Creating and Editing Features

Feature Modeling lets you create features such as holes, extrudes and

revolves on a model. You can then directly edit the dimensions of the

feature and locate the feature by dimensions. For example, a Hole is

defined by its diameter and length. You can directly edit all of these

parameters by entering new values. You can create solid bodies of any

desired design that can later be defined as a form feature using User

Defined Features. This lets you create your own custom library of form

features.
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Associatively

Associatively is a term that is used to indicate geometric

relationships between individual portions of a model. These relationships

are established as the designer uses various functions for model

creation. In an associative model, constraints and relationships are

captured automatically as the model is developed. For example, in an

associative model, a through hole is associated with the faces that the

hole penetrates. If the model is later changed so that one or both of those

faces moves, the hole updates automatically due to its association with

the faces. See Introduction to Feature Modeling for additional details.

Positioning a Feature

Within Modeling, you can position a feature relative to the

geometry on your model using Positioning Methods, where you position

dimensions. The feature is then associated with that geometry and will

maintain those associations whenever you edit the model. You can also

edit the position of the feature by changing the values of the positioning

dimensions.

Reference Features

You can create reference features, such as Datum Planes, Datum

Axes and Datum CSYS, which you can use as reference geometry when

needed, or as construction devices for other features. Any feature created

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using a reference feature is associated to that reference feature and

retains that association during edits to the model. You can use a datum

plane as a reference plane in constructing sketches, creating features,

and positioning features. You can use a datum axis to create datum

planes, to place items concentrically, or to create radial patterns.

Expressions

The Expressions tool lets you incorporate your requirements

and design restrictions by defining mathematical relationships between

different parts of the design. For example, you can define the height of a

extrudes as three times its diameter, so that when the diameter changes,

the height changes also.

Undo

You can return a design to a previous state any number of

times using the Undo function. You do not have to take a great deal of

time making sure each operation is absolutely correct, because a mistake

can be easily undone. This freedom to easily change the model lets you

cease worrying about getting it wrong, and frees you to explore more

possibilities to get it right.

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Additional Capabilities

Other Uni-graphics applications can operate directly on solid

objects created within Modeling without any translation of the solid

body. For example, you can perform drafting, engineering analysis, and

NC machining functions by accessing the appropriate application. Using

Modeling, you can design a complete, unambiguous, three dimensional

model to describe an object. You can extract a wide range of physical

properties from the solid bodies, including mass properties. Shading and

hidden line capabilities help you visualize complex assemblies. You can

identify interferences automatically, eliminating the need to attempt to

do so manually. Hidden edge views can later be generated and placed on

drawings. Fully associative dimensioned drawings can be created from

solid models using the appropriate options of the Drafting application. If

the solid model is edited later, the drawing and dimensions are updated

automatically.

Usage Notes

All bodies must be within a 1000 x 1000 x 1000 meter cube,

centered about the origin of the absolute coordinate system. (See the

Gateway Help for more information about the Absolute CSYS.)When

using a spline as a guide curve (such as when using extrude along guide,

or simplifying a spline), the spline is approximated into arcs and lines

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using the distance tolerance. If the spline is long and nearly straight and

the default distance tolerance (0.01") is used, the spline is approximated

using a large arc whose radius could be outside the maximum part size

limit of 1000 x 1000 x 1000 meters. You can avoid this problem by

increasing the distance tolerance.

The smallest linear value that can be applied to a body is 0.00000001

meters (which is equivalent to 0.00001 millimeters or 0.00000039

inches).Any linear value less than or equal to the above is considered to

be zero for operations on bodies. If you perform a Boolean operation

between a view dependent solid body and a model solid, the target solid

controls the resultant body. However, if you perform an undo, both

bodies are restored. Save any changes made to your layout before

entering the Drafting application. If you do not save the changes, they

are lost when you return to the Modeling application.

Parent/Child Relationships

If a feature depends on another object for its existence, it is a

child or dependent of that object. The object, in turn, is a parent of its

child feature. For example, if a HOLLOW (1) is created in a BLOCK (0),

the block is the parent and the hollow is its child. A parent can have

more than one child, and a child can have more than one parent. A

feature that is a child can also be a parent of other features. To see all of
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the parent-child relationships between the features in your work part,

open the Part Navigator.

3.2. Creating a Solid Model

Modeling provides the design engineer with intuitive and

comfortable modeling techniques such as sketching, feature based

modeling, and dimension driven editing. An excellent way to begin a

design concept is with a sketch. When you use a sketch, a rough idea of

the part becomes represented and constrained, based on the fit and

function requirements of your design. In this way, your design intent is

captured. This ensures that when the design is passed down to the next

level of engineering, the basic requirements are not lost when the design

is edited.

The strategy you use to create and edit your model to form

the desired object depends on the form and complexity of the object. You

will likely use several different methods during a work session. The next

several figures illustrate one example of the design process, starting with

a sketch and ending with a finished model. First, you can create a sketch

"outline" of curves. Then you can sweep or rotate these curves to create a

complex portion of your design.

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Introduction to Drafting

The Drafting application is designed to allow you to create

and maintain a variety of drawings made from models generated from

within the Modeling application. Drawings created in the Drafting

application are fully associative to the model. Any changes made to the

model are automatically reflected in the drawing. This associatively

allows you to make as many model changes as you wish. Besides the

powerful associatively functionality, Drafting contains many other useful

features including the following:

An intuitive, easy to use, graphical user interface. This allows you to

create drawings quickly and easily.

A drawing board paradigm in which you work "on a drawing." This

approach is similar to the way a drafter would work on a drawing board.

This method greatly increases productivity.

Support of new assembly architecture and concurrent engineering.

This allows the drafter to make drawings at the same time as the

designer works on the model.

The capability to create fully associative cross-sectional views with

automatic hidden line rendering and crosshatching.

Automatic orthographic view alignment. This allows you to quickly

place views on a drawing, without having to consider their alignment.

Automatic hidden line rendering of drawing views.

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The ability to edit most drafting objects (e.g., dimensions, symbols,

etc.) from the graphics window. This allows you to create drafting objects

and make changes to them immediately.

On-screen feedback during the drafting process to reduce rework and

editing.

User controls for drawing updates, which enhance user productivity.

Finally, you can add form features, such as chamfers, holes, slots,

or even user defined features to complete the object.

Updating Models

A model can be updated either automatically or manually. Automatic

updates are performed only on those features affected by an appropriate

change (an edit operation or the creation of certain types of features). If

you wish, you can delay the automatic update for edit operations by

using the Delayed Update option. You can manually trigger an update of

the entire model. You might, for example, want to use a net null update

to check whether an existing model will successfully update in a new

version of Uni-graphics -3before you put a lot of additional work into

modifying the model. (A net null update mechanism forces a complete

update of a model, without changing it.)

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The manual methods includes:

The Playback option on the Edit Feature dialog, which recreates the

model, starting at its first feature. You can step through the model as it

is created one feature at a time, move forward or backward to any

feature, or trigger an update that continues until a failure occurs or the

model is complete.

The Edit during Update dialog, which appears when you choose

Playback, also includes options for analyzing and editing features of the

model as it is recreated (especially useful for fixing problems that caused

update failures).Methods that users have tried in the past that has led to

some problems or is tricky to use:

One method uses the Edit Feature dialog to change the value of a

parameter in each root feature of a part, and then change it back before

leaving the Edit Feature dialog. This method produces a genuine net null

update if used correctly, but you should ensure that you changed a

parameter in every root feature (and that you returned all the parameters

to their original values) before you trigger the update.

Another method, attempting to suppress all of the features in a

part and then unsuppressed them, can cause updates that are not net

null and that will fail. The failures occur because not all features are

suppressible; they are left in the model when you try to suppress all
 26

features. As the update advances, when it reaches the point where most

features were suppressed, it will try to update the features that remain

(this is like updating a modified version of the model). Some of the

"modifications" may cause the remaining features to fail. For these

reasons, we highly recommend that you do not attempt to update models

by suppressing all or unsurprising all features. Use the other options

described here, instead.

Assemblies Concepts

Components

Assembly part files point to geometry and features in the subordinate

parts rather than creating duplicate copies of those objects at each level

in the assembly. This technique not only minimizes the size of assembly

parts files, but also provides high levels of associatively. For example,

modifying the geometry of one component causes all assemblies that use

that component in the session to automatically reflect that change. Some

properties, such as translucency and partial shading (on the Edit Object

Display dialog), can be changed directly on a selected component. Other

properties are changed on selected solids or geometry within a

component. Within an assembly, a particular part may be used in many

places. Each usage is referred to as a component and the file containing

the actual geometry for the component is called the component part.
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Top-down or skeleton or Bottom-up Modeling

You are not limited to any one particular approach to building the

assembly. You can create individual models in isolation, and then later

add them to assemblies (bottom-up), or you can create them directly at

the assembly level (top-down). For example, you can initially work in a

top-down fashion, and then switch back and forth between bottom-up

and top-down modeling.

Multiple Loaded Parts

Many parts can be simultaneously loaded at any given time.

These parts may have been loaded explicitly (such as with the Assembly

Navigator's Open options), or implicitly as a result of being used by some

other loaded assembly. Loaded parts do not have to belong to the same

assembly. The part currently displayed in the graphics window is called

the displayed part. You can make edits in parallel to several parts by

switching the displayed part back and forth among those parts. The

following figure shows two different assembly parts (MOUNT_ASSY.PRT

and MOUNT2_ASSY.PRT) which both use many of the same components.

The difference in the two is that due to a design change, assembly

MOUNT2_ASSY.PRT uses components BODY2 and BUSHING2, which

differ slightly from those used by MOUNT_ASSY.PRT (BODY and

BUSHING). The remaining components are used by both assemblies.

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The following scenario illustrates how component parts used by multiple

assemblies are loaded:

Before you open a file, there is no displayed part or any loaded parts.

When you open MOUNT_ASSY.PRT, component parts BOLT,

BUSHING, BODY, NUT, PIN, and YOKE are also loaded.

MOUNT_ASSY.PRT becomes the displayed part and the work part.

If you then open MOUNT2_ASSY.PRT, only the component parts not

also used by the previously opened assembly (BODY2 and BUSHING2)

are loaded. MOUNT2_ASSY.PRT then becomes the displayed part and

work part.

You could also open up a third assembly part that does not share any

common components with the previously opened files. The new assembly

part and all component parts it uses are then loaded, and the new

assembly part becomes the displayed part and work part

Design in Context

When the displayed part is an assembly, it is possible to change

the work part to any of the components within that assembly (except for

unloaded parts and parts of different units). Geometry features, and

components can then be added to or edited within the work part.

Geometry outside of the work part can be referenced in many modeling

operations. For example, control points on geometry outside of the work

 29

part can be used to position a feature within the work part. When an

object is designed in context, it is added to the reference set used to

represent the work part.

Associatively Maintained

Geometric changes made at any level within an assembly result

in the update of associated data at all other levels of affected assemblies.

An edit to an individual piece part causes all assembly drawings that use

that part to be updated appropriately. Conversely, an edit made to a

component in the context of an assembly results in the update of

drawings and other associated objects (such as tool paths) within the

component part. See the next two figures for examples of top-down and

bottom-up updates.

Mating Conditions

Mating conditions let you position components in an assembly.

This mating is accomplished by specifying constraint relationships

between two components in the assembly. For example, you can specify

that a cylindrical face on one component is to be coaxial with a conical

face on another component. You can use combinations of different

constraints to completely specify a component's position in the assembly.

The system considers one of the components as fixed in a constant

location, and then calculates a position for the other component which
 30

satisfies the specified constraints. The relationship between the two

components is associative. If you move the fixed component's location,

the component that is mated to it also moves when you update. For

example, if you mate a bolt to a hole, if the hole is moved, the bolt moves

with it.

Using Reference Sets to Reduce the Graphic Display

Large, complex assemblies can be simplified graphically by

filtering the amount of data that is used to represent a given component

or subassembly by using reference sets. Reference sets can be used to

drastically reduce (or even totally eliminate) the graphical representation

of portions of the assembly without modifying the actual assembly

structure or underlying geometric models. Each component can use a

different reference set, thus allowing different representations of the

same part within a single assembly. The figure below shows an example

of a bushing component used twice in an assembly, each displayed with

a different reference set.

When you open an assembly, it is automatically updated to

reflect the latest versions of all components it uses. Load Options lets

you control the extent to which changes made by other users affect your

assemblies. Drawings of assemblies are created in much the same way

as piece part drawings. You can attach dimensions, ID symbols and

other drafting objects to component geometry. A parts list is a table

 31

summarizing the quantities and attributes of components used in the

current assembly. You can add a parts list to the assembly drawing

along with associated callout symbols, all of which are updated as the

assembly structure is modified. See the following figure.

Machining of Assemblies

Assembly parts may be machined using the Manufacturing

applications. An assembly can be created containing all of the setup,

such as fixtures, necessary to machine a particular part. This approach

has several advantages over traditional methods:

It avoids having to merge the fixture geometry into the part to be

machined.

It lets the NC programmer generate fully associative tool paths for

models for which the programmer may not have write access privilege.

It enables multiple NC programmers to develop NC data in separate

files simultaneously.
 32

3.2. 3D MODEL

Specifications of the sprocket used for the design of the model are taken

by reverse engineering from pulsar 180 and are shown below:

Number of the teeth: 42

Roller diameter : 8.51mm

Sprocket thickness: 7.2 mm

Chain pitch:12.7mm

Sprocket diameter: 170 mm

The modeling of the sprocket is done in the NX-7.5

 33

FIG 3.2.1:

The above fig.3.2.1 shows the sketch drawn for the sprocket

The completed 3d model of the sprocket is shown in the below figure

FIG 3.2.2:
 34

The above fig.3.2.2 shows the 3d sprocket model

The 2d views of the sprocket modeled are shown if the below drafting

figure

FIG 3.2.3:

The above figure.3.2.3 represents the drafting of the sprocket

 35

3.3. INTRODUCTION TO ANSYS

The ANSYS program is self contained general purpose finite

element program developed and maintained by Swason Analysis Systems

Inc. The program contain many routines, all inter related, and all for

main purpose of achieving a solution to an engineering problem by finite

element method.

ANSYS finite element analysis software enables engineers to perform the

following tasks:

Build computer models or transfer CAD models of structures,

products, components, or systems.

Apply operating loads or other design performance conditions

Study physical responses ,such as stress levels, temperature

distributions, or electromagnetic fields

Optimize a design early in the development process to reduce

production costs.

Do prototype testing in environments where it otherwise would be

undesirable or impossible

The ANSYS program has a compressive graphical user interface (GUI)

that gives users easy, interactive access to program functions,

commands, documentation, and reference material. An intuitive menu

 36

system helps users navigate through the ANSYS Program. Users can

input data using a mouse, a keyboard, or a combination of both. A

graphical user interface is available throughout the program, to guide

new users through the learning process and provide more experienced

users with multiple windows, pull-down menus, dialog boxes, tool bar

and online documentation.

ORGANIZATION OF THE ANSYS PROGRAM

The ANSYS program is organized into two basic levels:

Begin level

Processor (or Routine) level

The begin level acts as a gateway in to and out of the ANSYS program.

It is also used for certain global program controls such as changing the

job name, clearing (zeroing out) the database, and copying binary files.

When we first enter the program, we are at the begin level.

At the processor level, several processors are available; each processor

is a set of functions that perform a specific analysis task. For example,

the general preprocessor (PREP7) is where we build the model, the

solution processor(SOLUTION)is where we apply loads and obtain the

solution, and the general postprocessor(POST1) is where we evaluate the

results and obtain the solution. An additional postprocessor (POST26),

 37

enables we to evaluate solution results at specific points in the model as

a function of time.

PERFORMING A TYPICAL ANSYS ANALYSIS

The ANSYS program has many finite element analysis capabilities,

ranging from a simple, linear, static analysis to a complex, nonlinear,

transient dynamic analysis. The analysis guide manuals in the ANSYS

documentation set describe specific procedures for performing analysis

for different engineering disciplines.

A typical ANSYS analysis has three distinct steps:

Build the model

Apply loads and obtain the solution

Review the results

The following table shows the brief description of steps followed in each

phase.

Pre-Processor Solution processor Post-processor

Assigning element type Analysis definition Read results

Geometry definition Constant definition Plot results on graphs

Assigning real constants Load definition View animated results

 38

Material definition Solve

Mesh generation

Model display

PRE-PROCESSOR:

The input data for an ANSYS analysis are prepared using a preprocessor.

The general preprocessor (PREP 7) contains powerful solid modeling an

mesh generation capabilities, and is also used to define all other analysis

data with the benefit of date base definition and manipulation of analysis

data. Parametric input, user files, macros and extensive online

documentation are also available, providing more tools and flexibility

For the analyst to define the problem. Extensive graphics capability is

available through out the ANSYS program, including isometric,

perceptive, section, edge, and hidden-line displays of three-dimensional

structures-y graphs of input quantities and results, ands contour

displays of solution results.

The pre-processor stage involves the following:

Specify the title, which is the name of the problem. This is optional

but very useful, especially if a number of design iterations are to be

completed on the same base mode.

 39

Setting the type of analysis to be used ,e.g., Structural, Thermal,

Fluid, or electromagnetic, etc

Creating the model. The model may be created in pre-processor, or it

can be imported from another CAD drafting package via a neutral file

format.

Defining element type, these chosen from element library.

Assigning real constants and material properties like youngs

modules, Poissons ratio, density, thermal conductivity, damping

effect, specific heat, etc

Apply mesh. Mesh generation is the process of dividing the analysis

continuum into number of discrete parts of finite elements.

SOLUTION PROCESSOR

Here we create the environment to the model, i.e, applying constraints

&loads. This is the main phase of the analysis, where the problem can be

solved by using different solution techniques. Her three major steps

involved:

Solution type required, i.e. static, modal, or transient etc., is selected

Defining loads. The loads may be point loads, surface loads; thermal

loads like temperature, or fluid pressure, velocity are applied.

Solve FE solver can be logically divided in o three main steps, the pre-

solver, the mathematical-engine and post-solver. The pre-solver reads

 40

the model created by pre-processor and formulates the mathematical

representation of the model and calls the mathematical-engine, which

calculates the result. The result return to the solver and the post

solver is used to calculate strains, stresses, etc., for each node within

the component or continuum.

POST PROCESSOR:

Post processing means the results of an analysis. It is probably the

most important step in the analysis, because we are trying to understand

how the applied loads affects the design, how food your finite element

mesh is, and so on.

The analysis results are reviewed using postprocessors, which

have the ability to display distorted geometries, stress and strain

contours, flow fields, safety factor contours, contours of potential filed

results; vector field displays mode shapes and time history graphs. The

postprocessor can also be used for algebraic operations, database

manipulators, differentiation, and integration of calculated results.

Response spectra may be generated from dynamic analysis. Results from

various loading may be harmonically loaded axis metric structures.

 41

REVIEW THE RESULTS:

Once the solution has been calculated, we can use the ANSYS

postprocessor to review the results. Two postprocessors are available:

POST1 and POST 26. We use POST 1, the general postprocessor to

review the results at one sub step over the entire model or selected

portion of the model. We can obtain contour displays, deform shapes and

tabular listings to review and interpret the results of the analysis. POST

1 offers many other capabilities, including error estimation, load case

combination, calculation among results data and path operations.

We use POST 26, the time history post processor, to review results

at specific points in the model over all time steps. We can obtain graph

plots of results, data vs. time and tabular listings. Other POST 26

capabilities include arithmetic calculations and complex algebra.

In the solution of the analysis the computer takes over and solves

the simultaneous set of equations that the finite element method

generates, the results of the solution are

Nodal degree of freedom values, which form the primary

solution

Derived values which form the element solution

 42

MESHING:

Before meshing the model and even before building the model, it is

important to think about weather a free mesh or a mapped mesh is

appropriate for the analysis. A free mesh has no restrictions in terms of

element shapes and has no specified pattern applied to it.

Compare to a free mesh, a mapped mesh is restricted in terms of

the element shape it contains and the pattern of the mesh. A mapped

area mesh contains either quadrilateral or only triangular elements,

while a mapped volume mesh contains only hexahedron elements. If we

want this type of mesh, we must build the geometry as series of fairly

regular volumes and/or areas that can accept a mapped mesh.

FREE MESHING:

In free meshing operation, no special requirements restrict the

solid model. Any model geometry even if it is regular, can be meshed. The

elements shapes used will depend on whether we are meshing areas or

volumes. For area meshing, a free mesh can consist of only quadrilateral

elements, only triangular elements, or a mixture of the two. For volume

meshing, a free mesh is usually restricted to tetrahedral elements.

Pyramid shaped elements may also be introduced in to the tetrahedral

mesh for transitioning purposes.

 43

MAPPED MESHING

We can specify the program use all quadrilateral area elements, all

triangular area elements or all hexahedra brick volume elements to

generate a mapped mesh. Mapped meshing requires that an area or

volume be regular, i.e., it must meet certain criteria. Mapped meshing

is not supported when hard points are used. An area mapped mesh

consists of either all quadrilateral elements or all triangular elements

For an area to accept a mapped mesh the following conditions must be

satisfied:

The area must be bounded by either three or four lines

The area must have equal numbers of element divisions specified on

opposite sides, or have divisions matching one transition mesh

patterns.

If the area is bounded by three lines, the number of element divisions

must be even and equal on all sides

The machine key must be set to mapped. This setting result in a

mapped mesh of either all quadrilateral elements or all triangular

elements depending on the current element type and shape key.

Area mapped meshes shows a basic area mapped mesh of all

quadrilateral elements and a basic area mapped mesh of all triangular

elements.
 44

STRUCTURAL STATIC ANALYSIS:

A static analysis calculates the effects of study loading conditions

on a structure, while ignoring inertia and damping effects, such as those

caused by time varying loads. A static analysis can however include

steady inertia loads and time varying loads that can be approximated as

static equivalent loads. Static analysis is used to determine the

displacements, stresses, strains and forces in structures or components

caused by loads that do not induce significant inertia and damping

effects. Steady loading and response conditions are assumed, i.e. the

loads and the structures responses are assumed to vary slowly with

respect to time. The kinds of loading that can be applied in static

analysis include:

Externally applied forces and pressures.

Steady state inertial forces

Imposed displacement

Temperatures

Fluences (for nuclear swelling)

 45

5.OBJECTIVES

Now a day most of the motorbikes have conventional chain drive by

which power is transmitted from engine to rear wheel. Chain drive

consists of two main parts, one is chain and other is sprocket. Mostly

chain and sprocket are made of mild steel material.

The main objective of this project is to do static and fatigue analysis of

the sprocket, and to find out the deflections, stresses and total life cycles

of the sprocket under working conditions.

 46

ANALYSIS OF THE SPROCKET IN ANSYS SOFTWARE

The 3d model of sprocket is made in the NX-7.5 and then it is converted

in the parasolid file. The parasolid file is imported in the ansys to

perform the static analysis with mild steel material.

Above fig.5.1 represents the 3d model in the ansys environment

The properties of the mild steel material used in this analysis are shown

below:
 47

PROPERTY VALUE

Youngs Modulus 2.1e5 MPa

Poissons ratio 0.3

Density 7850 kg/m3

Yield stress 250 MPa

Ultimate tensile stress 390 MPa

Element Types used:

Name of the Element: SOLID 187

Number of Nodes: 10

DOF: UX, UY & UZ

SOLID187 Element Description:

The above figure.5.2 shows the solid geometry of solid 187

 48

SOLID187 element is a higher order 3-D, 10-node element. SOLID187

has a quadratic displacement behavior and is well suited to modeling

irregular meshes (such as those produced from various CAD/CAM

systems).

The element is defined by 10 nodes having three degrees of freedom at

each node: translations in the nodal x, y, and z directions. The element

has plasticity, hyper elasticity, creep, stress stiffening, large deflection,

and large strain capabilities. It also has mixed formulation capability for

simulating deformations of nearly incompressible astoplastic materials,

and fully incompressible hyperelastic materials.

Boundary conditions:

The boundary conditions applied on the body i.e. constrains and the

forces applied are shown in below figures. After meshing, sprocket is

constrained in the center and the force is applied on the select part of the

circumference.
 49

The meshed model is shown in the above figure.5.3

The above figure.5.4 shows the applied boundary conditions

 50

6. RESULTS

Static analysis:

The results obtained for the static analysis of the sprocket in ansys are

shown below by plotting deflections and stresses.

Deflections:

The deflections obtained in the different directions are plotted below

The maximum deflections obtained in the x direction are plotted in

the below figure.

The above fig.6.1 shows the deflection in x direction

 51

The maximum deflections obtained in the y direction are plotted in the

below figure.

The above fig.6.2 shows the deflection in y direction

The maximum deflections obtained in the z direction are plotted in the

below figure.
 52

The above fig.6.3 shows the deflection in z direction

The total deflection obtained is shown in the below figure

 53

The usum deflection is shown in above fig.6.4

 54

Stresses:

The stresses developed in the static analysis are plotted below.

The stresses developed in the x component are shown below

The above fig.6.5 shows the x component of the stress

 55

The stresses developed in the y component are shown below

The above fig.6.6 shows the y component of the stress

The stresses developed in the z component are shown below

 56

The above fig.6.7 shows the z component of the stress

The 1st principal stress developed is shown in the below figure

 57

The above fig.6.8 shows the 1st principal stress

The 2nd principal stress developed is shown in the below figure

The above fig.6.9 shows the 2nd principal stress

The 3rd principal stress developed is shown in the below figure

 58

The above fig.6.10 shows the 3rd principal stress

 59

The von mises stress obtained in analysis are shown below

The above fig.6.11 shows the von mises stress

Obtained results:

Total deflection: 0.03mm

Von mises stress: 27.8 N/mm2

1st principal stress: 31.9 N/mm2

2nd principal stress: 12.6/mm2

 60

3rd principal stress: 10.4N/mm2

Fatigue analysis:

The steps involved in the fatigue analysis by using fatigue calculations

tool are shown below.

The below figure shows the goodmans diagram:

 61

The x axis in the above figure represents the Mean stress(MPa) and

The y axis represents the Alternating stress(MPa).

The below figure shows the input data for the fataigue life calculations
 62

The Goodman diagram obtained is show in the below figure

The results concluded from the Goodman diagram are

The above fig shows the life of component in cycles

 63

7. CONCLUSIONS

After the static analysis of the model that is made in NX-7.5 and

imported into ansys, the deflections obtained and stresses developed are

very well below the critical value and the design is found to be safe.

Total deflection: 0.03 mm

Von mises stress: 27.8 N/mm2

After fatigue analysis to find life cycles, it is clear that the design is

having infinite number of life cycles with very less mean stress.
 64

REFERENCES

Ebhota Williams S, Ademola Emmanuel, Oghenekaro Peter, (2014),

Fundamentals of Sprocket Design and Reverse Engineering of Rear

Sprocket of a Yamaha CY80 Motorcycle, International Journal of

Engineering and Technology, 4, pp. 170- 179.

Swapnil Ghodake, Prashant Deshpande, Shrikant Phadatare, (2014),

Optimization of Excavator Sprocket and its Validation by Test Rig

Concept, Conference on Advances in Engineering and Technology, pp.

253-256.

Chandraraj Singh Baghel, Abhishek Jain, Dr. A.K. Nema and Anil

Mahapatra, (2013), Software ANSYS Based Analysis on Replacement

of Material of Sprocket Metal to Plastic Material PEEK, International

Research Journal of Engineering and Applied Science, 1 (4).

Chaitanya G Rothe, A. S. Bombatkar , (2015), Design and Analysis of

Composite Material Drive Shaft, International Journal of Innovative

and Emerging Research in Engineering, 2 (1), pp. 72-84.

R. V. Mulik, Prof. M. M. Joshi, Dr. S. Y. Gajjal, S. S. Ramdasi and N.

V. Marathe, (2014), Dynamic Analysis of Timing Chain System of a

 65

High Speed Three Cylinder Diesel Engine, International Journal of

Engineering and Science, 4 (5), pp. 21-25.

Candida Pereira, Jorge Ambrosia, Amilcar Ramalho, (2010), Contact

Mechanics In A Roller Chain Drive Using A Multibody Approach, 11th

Pan-American Congress of Applied Mechanics Copyright 2009 by

ABCM January 04-08.

Sine Leergaard Pedersen, (2014), Simulation and Analysis of Roller

Chain Drive Systems, PHD Dissertation, technical university of

Denmark.

C Conwell, (1989), An Examination of Transient Forces in Roller

Chain Drives, Ph.D. Dissertation: Vanderbilt University, Nashville, TN.