Reducing Effect.full

REDUCING EFFECT OF BENDING LOAD AND TORQUE LOAD ON A HEAVY VEHICLE

FRONT AXLE USING COMPOSITES

RAJASEKHAR J1, SAMA BHARGAV

2 & SAGINA DOONDI NAGARJUNA

3

1Associate Professor, Department of Mechanical Engineering, PEC, Andhra Pradesh, India

2,3UG Student, Department of Mechanical Engineering, PEC, Andhra Pradesh, India

ABSTRACT

An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels,

rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. Conventionally the front axle is a

dead axle. In such a case, the front axle beam is usually a drop forging of steel. This type of axle is no more used in modern

cars, although it is still being used in heavier vehicles. The steels used for this are 0.4% carbon steel or 1.3% nickel steel.

The axle has to take bending loads due to weight of the vehicle and also torque loads due to braking of the wheels. For this

reason, front axle is made of I section in the central portion, while the ends are made either circular or elliptical.

A downward sweep is given to the center portion to keep a low chassis height. In our project, a basic model of front axle is

prepared. The optimization of front axle is done by varying materials and its cross section. The present used material used

steel. Steel is replaced with Composite materials E-Glass Epoxy and S 2 Glass epoxy to reduce the weight of the axle.

By reducing the weight, steering becomes easier. Pro/Engineer is used for modeling and ANSYS is used for analysis.

KEYWORDS: Rigid Axle, Composite Materials, CADD, Pro-E, ANSYS9.0, Motor Vehicles

INTRODUCTION

Front Axle: Conventionally the front axle is a dead axle. In such a case, the front axle beam is usually a drop

forging of steel. This type of axle is no more used in modern cars, although it is still being used in heavier vehicles.

The steels used for this are 0.4% carbon steel or 1.3% nickel steel. The axle has to take bending loads due to weight of the

vehicle and also torque loads due to braking of the wheels. For this reason, front axle is made of I section in the central

portion, while the ends are made either circular or elliptical. A downward sweep is given to the center portion to keep a

low chassis height.

Composites: The concept of composites was not invented by human beings; it is found in nature. An example is

wood, which is a composite of cellulose fibers in a matrix of natural glue called lignin. The shell of invertebrates, such as

snails and oysters, is an example of a composite. Such shells are stronger and tougher than man-made advanced

composites. Scientists have found that the fibers taken from a spiders web are stronger than synthetic fibers.

CAD also known as Computer Aided Design, is the use of computer technology for the process of design and

design-documentation. Computer Aided Drafting describes the process of drafting with a computer. CAD software, or

environments, provide the user with input-tools for the purpose of streamlining design processes; drafting, documentation,

and manufacturing processes. CAD is mainly used for detailed engineering of 3D models and/or 2D drawings of physical

components, but it is also used throughout the engineering process from conceptual design and layout of products, through

strength and dynamic analysis of assemblies to definition of manufacturing methods of components. It can also be used to

design objects.

International Journal of Mechanical and

Production Engineering Research and

Development (IJMPERD)

ISSN 2249-6890

Vol. 3, Issue 4, Oct 2013, 99-106

TJPRC Pvt. Ltd.

http://en.wikipedia.org/wiki/Computerhttp://tjprc.org/journals.php?jtype=2&id=67http://tjprc.org/journals.php?jtype=2&id=67http://tjprc.org/journals.php?jtype=2&id=67

100 Rajasekhar J, Sama Bhargav & Sagina Doondi Nagarjuna

PRO/ENGINEER WILDFIRE

Pro/ENGINEER Wildfire is the standard in 3D product design, featuring industry-leading productivity tools that

promote best practices in design while ensuring compliance with your industry and company standards. Integrated

Pro/ENGINEER CAD/CAM/CAE solutions allow you to design faster than ever, while maximizing innovation and quality

to ultimately create exceptional products.

The main modules are Part Design, Assembly, Drawing and Sheet Metal

PRESENT MODEL OF FRONT AXLE

Figure 1: Step 1 Figure 2: Step 2



Reducing Effect of Bending Load and Torque Load on a Heavy Vehicle Front Axle Using Composites 101


ABOUT FEA

Finite element analysis (FEA) was first developed in 1943 by r. Courant, who utilized the ritz method of

numerical analysis and minimization of variational calculus to obtain approximate solutions to vibration systems. Shortly

thereafter, a paper published in 1956 by m. J. Turner, r. W. Clough, h. C. Martin, and l. J. Top established a broader

definition of numerical analysis. The paper centered on the "stiffness and deflection of complex structures".

By the early 70's, FEA was limited to expensive mainframe computers generally owned by the aeronautics,

automotive, defense, and nuclear industries. Since the rapid decline in the cost of computers and the phenomenal increase

in computing power, FEA has been developed to an incredible precision. Present day supercomputers are now able to

produce accurate results for all kinds of parameters.

FEA consists of a computer model of a material or design that is stressed and analyzed for specific results. It is

used in new product design, and existing product refinement. A company is able to verify a proposed design will be able to

perform to the client's specifications prior to manufacturing or construction. Modifying an existing product or structure is

utilized to qualify the product or structure for a new service condition.in case of structural failure, FEA may be used to help

determine the design modifications to meet the new condition.

There are generally two types of analysis that are used in industry: 2-D modeling, and 3-D modeling. While 2-D

modeling conserves simplicity and allows the analysis to be run on a relatively normal computer, it tends to yield less

accurate results. 3-D modeling, however, produces more accurate results while sacrificing the ability to run on all but the

fastest computers effectively. Within each of these modeling schemes, the programmer can insert numerous algorithms

(functions) which may make the system behave linearly or non-linearly. Linear systems are far less complex and generally

do not take into account plastic deformation. Non-linear systems do account for plastic deformation, and many also are

capable of testing a material all the way to fracture.

FEA uses a complex system of points called nodes which make a grid called a mesh. This mesh is programmed to

contain the material and structural properties which define how the structure will react to certain loading conditions. Nodes

are assigned at a certain density throughout the material depending on the anticipated stress levels of a particular area.

Regions which will receive large amounts of stress usually have a higher node density than those which experience little or

no stress. points of interest may consist of: fracture point of previously tested material, fillets, corners, complex detail, and

high stress areas. The mesh acts like a spider web in that from each node, there extends a mesh element to each of the

adjacent nodes. This web of vectors is what carries the material properties to the object, creating many elements.

Ansys is general-purpose finite element analysis (FEA) software package. Finite element analysis is a numerical

http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/glossary.html#nodehttp://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/glossary.html#mesh


method of deconstructing a complex system into very small pieces (of user-designated size) called elements. The software

implements equations that govern the behaviour of these elements and solves them all; creating a comprehensive

explanation of how the system acts as a whole. These results then can be presented in tabulated, or graphical forms.

This type of analysis is typically used for the design and optimization of a system far too complex to analyze by hand.

Systems that may fit into this category are too complex due to their geometry, scale, or governing equations.

Ansys is the standard FEA teaching tool within the mechanical engineering department at many colleges. Ansys is

also used in civil and electrical engineering, as well as the physics and chemistry departments. Ansys provides a

cost-effective way to explore the performance of products or processes in a virtual environment. This type of product

development is termed virtual prototyping. With virtual prototyping techniques, users can iterate various scenarios to

optimize the product long before the manufacturing is started. This enables a reduction in the level of risk, and in the cost

of ineffective designs. The multifaceted nature of ansys also provides a means to ensure that users are able to see the effect

of a design on the whole behavior of the product, be it electromagnetic, thermal, mechanical etc.

STRUCTURAL AND MODAL ANALYSIS

Structural Analysis of Present Model: Material Steel

Figure 9 Figure 10: Meshed Model in Ansys

Figure 11: Meshed Model with the Loads

Element Type : Solid 20 node 95

Material Properties : EX = 200000N/mm2

PRXY = 0.295

Density = 0.000007872 kg/mm3

Loads : Pressure = 0.0769N/mm2


Solution

Solution Solve Current LS ok

Post Processor

General Post Processor Plot Results Contour Plot - Nodal Solution DOF Solution Displacement Vector

Sum

Figure 12: Displacement Vector Sum

General Post Processor Plot Results Contour Plot Nodal Solution Stress Von Mises Stress

Figure 13: Von Mises

Modal Analysis

Main menu>Preprocessor>Loads>Analysis Type>

New Analysis> Select Modal>Click> OK

Main menu>Preprocessor>Loads>Analysis Type>Analysis Options>

No. Of Modes to Extract: 5 Click> OK

Main menu>Solution>Solve>Current Ls>Ok


RESULTS

Main menu>General Postproc>Read Results> First Set

Plot result>Deformed Shape>Def+ Undeform > Click> OK

Figure 14: Def+ Undeform

MATERIAL E-GLASS EPOXY EPOXY

Structural Analysis of Present Model

Solution

Solution Solve Current LS ok

Post Processor

General Post Processor Plot Results Contour Plot - Nodal Solution DOF

Solution Displacement Vector Sum

Figure 15: Displacement Vector Sum

Element Type : Solid 20 node 95

Material Properties: EX = 50000N/mm2

PRXY = 0.33

Density = 0.000002kg/mm3


General Post Processor Plot Results Contour Plot Nodal Solutio n Stress Von Mises Stress

Figure 16: Von Mises Stress

Modal Analysis


New Analysis> Select Modal>Click> OK


Analysis Options>No. Of Modes to Extract: 5 Click> OK

Main menu>Solution>Solve>Current Ls>Ok

RESULTS

Main menu>General Postproc>Read Results> First Set

Plot result>Deformed Shape>Def+ Undeform > Click> OK

Figure 17: Def+ Undeform


RESULTS

Structural Analysis Results

Table 1: Present Model of Rigid Axle

Material Displacement (mm) Von Mises Stress (n/mm2) Permissible Stress (n/mm

2)

Steel 0.126539 17.257 620

E Glass Epoxy 0.051682 16.998 1000

Modal Analysis Results

Table 2: Present Model of Rigid Axle

Modes

Steel E Glass Epoxy

HZ mm HZ Mm

MODE 1 3.105 0.12 9.528 0.24

MODE 2 3.521 0.11 11.2 0.216

MODE 3 5.165 0.11 19.12 0.209

MODE 4 9.609 0.11 29.55 0.216

MODE 5 11.02 0.22 33.72 0.445

CONCLUSIONS

In our project we have modeled a front axle used in heavy vehicles in the 3D modeling software Pro/Engineer.

The present model is of I section and we have modeled another front axle. The weight of the actual model is

about 214kgs and that of modified model is about 181kgs. The weight of the front axle is reduced almost by

30kgs.

Present used material for front axle is steel. We are replacing with E-Glass Epoxy. The density of E-Glass Epoxy

is less than that of Steel. Thereby the weight of the front axle reduces when E-Glass Epoxy.

We have done structural analysis and modal analysis for model using Steel, E-Glass Epoxy to verify the strength

and determine the frequencies.

By observing the analysis results, the stress values obtained are less than their permissible stress values for the

two materials. So, E-Glass Epox is safe for front axle. The stress values are also within the limit.

By considering weight and analysis results, we conclude that S2 Glass Epoxy is better.

REFERENCES

1. Manufacturing of parts using composites from wikipedia

2. Mechanics of composite materials by authar. K. Kaw

3. Mechanics of laminated composite plates and shells- j. N. Reddy

4. Engineering mechanics of composite materials- issac m . Daniel

5. A text book of automobile engineering by r.k. Rajput, lp publications

6. Fundamentals of motor vehicle technology by v.a.w. Hillier,

howmesh

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Reducing Effect.full