FACULTY OF MECHANICAL ENGINEERINGUNIVERSITY OF TECHNOLOGY MARA

SHAH ALAM, SELANGOR

MEC532 MECHANICAL ENGINEERING DESIGN 1FINAL REPORT

PROJECT TITLE: DESIGN & FABRICATE A SINGLE SEATER VEHICLE

(CHASSIS)

TEAM LEADER : AHMAD HASSAN B MUHD MUHAYYIDIN SIGNATURE: (20133411786)

TEAM MEMBER : MOHAMAD HAZIM FAHMI BIN MOHD YAMIN SIGNATURE:

(2012226818)

TEAM MEMBER : MOHAMAD ZAID BIN MOHAMAD ZAILANI SIGNATURE: (2012241394)

TEAM MEMBER : MUHAMAD SHAFIQ BIN SAUFI SIGNATURE: (2012876726)

TEAM MEMBER : MOHAMAD FARIZ AIZAT BIN ABDAIN SIGNATURE: (2012223106)

TEAM MEMBER : KU SITI FATIMAH AZZAHRA’ BT KU MOKHTAR SIGNATURE:

(2012540029)

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PROJECT ADVISORS: Dr. AZIANTI ISMAIL

ABSTRACT

This design project is the requirement for Part 5 students of Faculty of Mechanical

Engineering. Each class were required to design a single seated vehicle which comprises 6

departments from each class which are chassis department, bodywork and safety department,

braking department, steering department, powertrain department and suspension department.

We are from chassis department were required to build a strong and light chassis for our

single seated vehicle. Aspects of ergonomics, safety, ease of manufacture and reliability are

incorporated into the design specifications. Analysis are conducted on all major components to

optimized strength and rigidity, improve vehicle components and to reduce complexity and

manufacturing costs.

3D models have been made for analysis purpose by using CATIA software and analysis

has been made. 3D assembly models of the single seated vehicle are designed for understanding

purpose.

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ACKNOWLEDGEMENT

Apart from the effort of us, this design project was done successfully because of the

encouragement and guidelines from many others. We would like to take this valuable

opportunity to express our gratitude to the people who have been a big help to us during

completion of this project.

First and foremost, We would like to thank our beloved lecturer Dr Azianti Ismail , who

has supported us throughout this project with his patience and knowledge. Guidance by him

physically and mentally is very valuable. He inspired us greatly to work in this project. His

willingness to motivate us contributed tremendously to our project. All these are the vital factors

which drive us till the end.

Secondly, we would like to offer our sincerest gratitude to members from other

department who provide us useful opinions and suggestions along the implementation of this

project. Their support made us able to complete this project. They are always by our side without

tired and fail when they are needed. Beneficial advices are obtained from them.

On the other hand, we would like to take this opportunity to thank our family members

for supporting and encouraging us during the completion of this project. Our deepest gratitude

from the bottom of our heart for the support, encouragement and inspirations we obtained during

this project.

Last but not least, we would like to thank everybody who was important to the successful

realization of this design project as well as expressing our apology that we could not mention

personally one by one.

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1.0 ORGANIZATION CHART

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GROUP LEADER

AHMAD HASSAN

SECRETARY

KU SITI FATIMAH AZZAHRA’

HEAD OF DESIGNERMUHAMMAD SHAFIQ ASSISTANT DESIGNER MOHAMAD ZAID

HEAD OF PRODUCTIONMOHAMAD FARIZ AIZAT ASSISTANT PRODUCTION MUHAMMAD HAZIM FAHMI

1.1 INTRODUCTION

Chassis is the most important part of fabricating of single seated vehicle. Its department

plays a very important role because it is much related to other components of the vehicle. The

change in dimension and design of chassis will affect the designation of other component of the

vehicle. Chassis consists of an internal framework that supports a man-made object in its

construction and use.

Chassis serves as an aero device, both by directing air but also by supporting the

deflection of other aero components. The chassis also act as the driver's center of confidence. If

the driver does not feel safe, either due to weak impact zones or flexi suspension feedback, he

will not go fast. Arguably more importantly, he may be injured by an unsafe chassis. Finally, the

driver must be entirely comfortable.

A good chassis must have following characteristics:

Be structurally sound in every way over the expected life of the vehicle and beyond. This

means nothing will ever break under normal conditions.

Maintain the suspension mounting locations so that handling is safe and consistent under

high cornering and bump loads.

Support the body panels and other passenger components so that everything feels solid

and has a long, reliable life.

Protect the driver from external injuries. For this project, we are going to build a single

seated vehicle based on SAE car formula. All specification will be based on SAE car

formula.

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PROJECT PLANNING

GANTT CHART

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2.0 LITERATURE REVIEW

2.1.1 Studies on Chassis Design

Functions of chassis design

1. To carry load of the passengers or goods carried in the body.

2. To support the load of the body, engine, gear and others system.

3. To withstand the forces caused due to the sudden raking or acceleration.

4. To withstand stresses caused due to the bad road condition.

5. The withstand centrifugal force while cornering.

Types of chassis frames

There are several types of chassis frames that have been studying such as:

1. Conventional frame

2. Integral frame

3. Semi-integral frame

Conventional frame

It has long side members and 5 to 6 cross members joined together with the help of rivets

and bolts. The frame sections used generally have 3 sections. The first section is channel

section which has good resistance to bending. Second is the tabular section which

supposedly has good resistance to torsion. Whereas the box section may has good

resistance to both bending and torsion.

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Figure 1: Conventional frames

Integral frame

This type of frame is used nowadays in most of the cars. There is no frame and all the

assembly units are attached to the body. All the functions of the frame carried out by the

body itself. Due to elimination of long frame it is cheaper and due to less weight and

most economical too. The disadvantage is difficulty in repairing of the chassis.

Figure 2: Integral frame

Semi-integral frame

In some vehicles, half frame is fixed in the front end on which engine gear box and front

suspension is mounted. It has the advantage when the vehicle is met with accident the

front frame can be taken easily to replace the damaged chassis frame. This type of frame

is used in FIAT cars and some of the European and American cars.

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Figure 3: Semi integral frame

Frame Loading

Generally there are various loads acting on the frame which is:

1. Short duration load – acted on frame while crossing a broken patch.

2. Momentary duration load – acted on frame while taking a curve.

3. Impact loads – acted on frame due to collision of the vehicle.

4. Inertia loads – may experience this load while applying brakes.

5. Static inertia – it is the loads due to chassis parts at static condition.

6. Over loads – happened when the load is beyond design capacity.

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2.1.2 Studies on Materials for Chassis

In this material selection part, we have to consider many properties of material before making the

choice. There several type of material that can be compared such as steel, aluminum and

titanium.

Steel

The properties that need to be considered:1. Strength2. Toughness3. Ductility4. Weldability – determined by the chemical content of the alloy, which is governed

by limits in the product standard.5. Durability – depends on the particular alloy type

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Figure 4: Schematic Stress Strain diagram for steel

Figure 5: Stress Strain behavior for steel

Aluminum

Properties Description Weight Very light with a density one third that of steel.Strength Tensile strength: 70 to 700 MPa strength will

decrease high temperature increase.Linear expansion Aluminum has relatively large coefficient of

linear expansionMachining Easy to be operated by machining such as

milling, drilling, cutting, punching, bending and many more. Plus, the force exerted duringmachining is low

Formability Aluminum's superior malleability is essential for extrusion. With the material either hot or cold, this property is also exploited in the rolling of strips and foils, as well as bending and other forming operations

Conductivity Excellent conductor of heat and electricity.Joining Able to join by fusion welding, friction stir

welding, bonding and taping.Reflectivity Good reflectivity of both visible light and

radiated heatScreening EMC Tight aluminum boxes can effectively exclude

or screen off electromagnetic radiation. The

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better the conductivity of a material, the better the shielding qualities.

Corrosion resistance Aluminum reacts with the oxygen in the air to form an extremely thin layer of oxides. This layer is dense and provides excellent corrosion protection. The layer is self-repairing if damaged. Aluminum is extremely durable in neutral and slightly acid environments. In environments characterized by high acidity or high basicity, corrosion is rapid.

Non-magnetic material Able to avoid interference of magnetic fields

Table 1: Properties of aluminum

Titanium

TEMPERATURE

Melting point: 1941 K (1668 oC / 3034 oF)

Boiling point: 3560 K (3287 oC / 5949 oF)

Liquid range: 1619 K

Critical temperature: no data K

Supercondition temperature: 0.40 K (-272.7 oC / -458.9 oF)

EXPANSION AND CONDUCTION PROPERTIES

Thermal conductivity: 21.9 Wm-1 K-1

Coefficient of linear thermal expansion: 8.6×10-6 K-1

BULK PROPERTIES

Density of solid: 4507 kg m-3

Molar volume: 10.64 cm3

Velocity of sound: 4140 ms-1

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ELASTICITY PROPERTIES

Young's modulus: 116 GPa

Rigidity modulus: 44 GPa

Bulk modulus: 110 GPa

Poisson's ratio: 0.32

HARDNESS

Mineral hardness: 6.0

Brinell hardness: 716 MNm-2

Vickers hardness: 9700 MNm-2

2.1.3 Studies on Joining of Chassis

Gas metal arc welding (GMAW) is an arc welding process in which the electrode is a

continuous and consumable bare metal wire, and a shielding gas are fed through a welding gun.

Wire diameters ranging from 0.8 to 6.5 mm are used in GMAW. The size depends on the

thickness of the parts being joined and the desire deposition rate. Gases are used for shielding

include inert gases such as argon and helium, and active gases such as carbon dioxide. Selection

of gases depends on the metal being welded, as well as other factors. Inert gases are used for

welding aluminum alloys and stainless steels, while CO2 are commonly used for welding low

and medium carbon steels.

Gas metal arc welding (GMAW), sometimes referred to by its subtype metal inert gas

(MIG) welding or active gas (MAG) welding. It is a semi-automatic or automatic arc welding

process. The welding process operates by using the direct current power source usually with the

wire electrode positive, is most commonly used with GMAW but constant current system, as

well as alternating current, can be used. This is known as reverse polarity where the straight

polarity is used because of the poor transfer of molten metal from the wire electrode to the

workpiece. There are four primary methods of metal transfer in GMAW, called globular, short-

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circulating, spray, and pulsed-spray, each of which has distinct properties and corresponding

advantages and limitations.

Figure 6: Gas metal arc welding

2.1 Design requirement

1. Only structural space frame chassis type are allowed ( no monocoque type )

2. The chassis must be made from structural steel or structural steel alloy tubing meeting the

ISO 4948 classifications and the ISO 4949 designations. Alloy steel having at least one

alloy element the mass content of which > 5% are forbidden.

3. The vehicle chassis must be equipped with an effective roll bar that extends 50mm

around the driver's helmet and also extends in width beyond the driver's shoulders when

seated in normal driving position.

4. Any roll bar must be capable of withstanding a static load of 700 N (approx.70kg )

applied in vertical, horizontal, or perpendicular direction, without deforming

5. The driver must have adequate visibility to the front and sides of the car. With the driver

seated in a normal driving position he/she must have a minimum field of vision of 200

degrees (a minimum 100 degrees to either side of the driver).

6. The required visibility may be obtained by the driver turning his/her head and/or use of

mirrors.

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7. The side impact structure for tube frame cars must be comprised of at least three (3)

tubular member located on each side of the driver while seated in the normal driving

position.

8. All necessary analysis and calculation (e.g. front and side impact analysis, roll bar

analysis, C.O.G location, structural strength analysis (bending/torsion), material use

analysis, joint method analysis (bolt/welding/other joint method)

3.0 PHASE 1: CONCEPTUAL DESIGN

3.0 Objectives

Striving to achieve the major aims, the chassis department focuses on

1. To perform aesthetic chassis design while fulfilling specification stated by faculty.

2. To perform a successful analysis of chassis of a single seated vehicle while incorporated

with all department.

3. To produce a complete reliable of 3D model chassis design of a single seated vehicle

with assist of CATIA software.

4. To design a chassis that will be easily adaptable and adjustable.

3.1 Problem Statement

1. The chassis must be equipped with an effective roll bar that extends 50mm around the

driver’s helmet.

2. The roll bar must capable to withstand 700N applied in a vertical, horizontal or

perpendicular direction without deforming.

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3. The minimum field of vision of driver must 100 degrees to either side of the driver.

4. The side impact structure must be comprised at least 3 tubular members located on each

side of the driver.

3.2 Product Design Specification

PRODUCT : Chassis for Formula Student Car

MASS : Approximate 40kg

SIZE : Length (2090mm), width (510mm), height (1050mm)

TIMESCALE : 18 weeks from initial phase to manufacturer.

COST : RM 176.70

QUANTITY : 51 pieces

SAFETY : Designed to hold collision impact since the frame not damage badly in case of accident.

COMPETITION : Various chassis from other FKM group

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MAINTAINANCE : Welded joint need to be inspected.

MANUFACTURING FACILITY : TIG Welding machine, grinder, cut off machine, hydraulic bending machine.

INSTALLATION : All of the pieces will be join by spot and TIG welding

MATERIALS : Mild Steel

3.3 Physical Decomposition

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Figure 7: Physical decomposition of chassis

Physically, chassis does not have physical component to dissect. Therefore the chassis is

divided into 4 subcomponents which are front component, central/cockpit component, rear

component, and bodywork component.

The front component will be design to install suspension system, braking system, and

steering system. While at the central of chassis it is where the brake pedal and the throttle pedal

will be located. As for rear component, we will design appropriate section for power train

installation, braking and suspension system. The whole bodywork of the chassis design must

have cooperation with bodywork department in order to achieve the aesthetic design of car body.

3.4 Functional Decomposition

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Figure 8: Functional decomposition of chassis

The chassis carrying few functions such as provide safety and reliability, acquire

ergonomic design, aerodynamic, high durability, high stability. Chassis must have strong and

rigid frame in order to provide safety for driver during impact. It must be reliable to absorb the

impact so that any injury on the driver can be avoided.

It is important for the chassis to be in ergonomic shape so that the chassis can have high

aesthetic value to attract people plus providing comfort and user friendly in which the driver

should be able to easily get into and out of the car. There also must not have any sharp edges

from the internal space to ensure the driver safety. The aerodynamic of the chassis will play an

important role for bodywork to design the car body; a good design of chassis will help in

increase velocity of the car.

The chassis frame must be durable as it is the main component where other systems will

be attached. It must able to withstand normal stress and shear stress. Other than that, the chassis

is design to be stable at all driving condition for example during static, cornering, high speed

condition, and braking condition. It must also able to withstand the vibration of the car to protect

internal system breakdown.

3.5 Morphological Chart

MATERIAL BAR SHAPE FRONT COCKPIT REARSTEEL

RECTANGLE

ALUMINIUM

ROUND

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Design 2

Design 3

Design 1

TITANIUM

OVAL

ALLOY

Figure 9: Morphological chart

Morphological chart is a pictorial approach to illustrate a designer’s ideas and help to

choose the best design to meet with the function requirement. Multiple designs for each of the

function are first listed in form of the table. Basic approach to create the chart is by listing the

function requirement on the left side of the table, while on the right side, different mechanisms

which can be used to perform the functions listed are drawn. A morphological chart can be a big

and complex chart based on the designer’s idea, function decomposition of each part and also

different mechanisms gathered from their literature review itself. The idea generation is finally

accomplished by creating single systems from different mechanisms illustrated in the

morphological chart.

Our chassis department had conducted a lot of research and review from various

resources including the chassis designed by the student before. Throughout brainstorming, we

learn that chassis design is basically can be decomposes to three major function which is cockpit,

front and rear frame. We understood that cockpit is the most crucial area as it is where the driver

is placed. So, it has to be built with the sense that it can bear the impact front all side of the

driver however it is also important to make sure the cockpit area is effective enough that it does

not significantly affect the overall weight and size of the car. The chart above shows 4 ideas of

cockpit design.

The front skeleton of the car is where the other part of the car is mounted. It is

interconnected with the suspension, braking and steering system. Front frame is also where the

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Design 4

braking and gas pedals are located. Based on this fact, it is necessary for the framework to be

well concomitant with the part’s joining point without neglecting the driver’s space to freely

handle the pedals. It is also important to guarantee that the driver is fully protected from the front

impact and absorb the impact at particular speed. However the attenuator design is charged under

bodywork department and is not being included here. The very last part is the rear frame which

can be considered as engine compartment.

3.6 Pugh Concept Selection Method

Criteria Weight Concept1 Concept2 Concept3 Concept4

Weight Of Chassis 6 - + + +

Durability 8 + + + -Cost 9 + - - -

Ergonomics 5 + + - -

Stability 8 + - - +

Safety 9 + + + -

Aesthetic value 3 + + + -

Aerodynamic 6 + + - -

Sum of +’s 7 6 4 2

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Sum of –‘s 1 2 4 6Total Weighted 42 20 -2 -26

Figure 10: Pugh Concept Selection Method

Pugh concept selection method is a method for concept selection using a scoring matrix

called the Pugh Matrix. It is implemented by establishing an evaluation team, and setting up a

matrix of evaluation criteria versus alternative embodiments. The scoring matrix usually

associated with the QFD method and is a form of prioritization matrix. These get converted into

scores and combined in the matrix to yield scores for each option.

Effective for comparing alternative concepts

Scores concepts relative to one another

Iterative evaluation method

Comparison of the scores generated gives insight into the best alternatives.

Based on the figure above, the concept 1 which is the design 1 attains the highest score

with weighted of 42. This is because in the design 1, the bar shape selected is rectangle cross

section shape. This shape can be easily found in the market in cheaper price. The front skeleton

chosen is the most practical shape for the chassis with enough support beam and easy to

assemble. The cockpit of design 1 has 3 tubular members as required from specification and the

roll bar is high, and easy to fabricate. Whereas at the rear skeleton, the design 1 compartment

engine is better compare to other type in the morphological chart. The 3rd design of rear skeleton

have smaller base. This will effect in terms of stability of the chassis. It provides large space yet

less complexity of geometry shape. In terms of scoring in the Pugh method the design 1 may fit

all others criteria except for the weight is the minus point due to few support that need to be

added to withstand load. Therefore, design 1 is chosen based on the high value in criteria of

durability, ergonomic shape, stability, safety, aesthetic value, aerodynamics but still in the lowest

cost.

For concept 2 there are two minus point on two criteria which is cost and stability. This

result in total weighted of 20. As for concept 3, it obtains the least total weighted of -2 due to

many minus point in four criteria which is the cost, stability, ergonomic and aerodynamic. The

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cost is high due to the using of I-bar cross section. This I-bar is very expensive same as in

concept 2. The cockpit skeleton is wider thus not good in terms of aerodynamic.

4.0 PHASE 2: EMBODIMENT DESIGN

4.1 Product Architecture

All structures are made from rectangular cross-sectional shape.

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Steering system

Suspension system

The product architecture is the arrangement of physical elements to carry out its required

function. Chassis play an important role to all others department function. Chassis will provide

space to assemble systems. The front skeleton is the position where the suspension system will

be installing. From the suspension system the braking system will attach its brake disc and others

component. In the same time, the steering department will attach its knuckles, and steering

system of rack and pinion.

On the rear skeleton, the chassis is design to fit the size of engine used that had been

decided by power train department and also for the back tires from suspension department and

braking department since brake system is on the all four tires. For the overall chassis, the

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Suspension system

Braking system

Power train

Bodywork and safety

Braking system

Front skeleton

Overall skeleton

Rear skeleton

bodywork and safety will design the skin of the body and also the attenuator, driver seat and

others important safety component of the car.

The chassis is Design for Human Factor in which the determination of the size of the

cockpit is by measuring the actual driver size. Besides, we also added up some tolerances to the

dimension of the driver size so that the driver can easily get into or out from the car. In the inside

of the framework, the bodywork department may also attach safety padding at the side to prevent

injury in case of high impact and provide comfort for driver.

4.2 Configuration Design

The designation of chassis is based on Human Factor thus measuring the driver size is at follows.

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Figure 11: Driver dimension

Our driver will be seated at that particular position and his shoulder width are also

measured. After added few tolerances and discussing with other department of system, the final

dimension is decided.

Figure 12: Base dimension of chassis

4.3 Product Development

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Figure 13: Flow chart of the product development

DESIGN 1

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Figure 14: Isometric view of design 1

The diagram shows the first design that we made. The first design does not have enough

support therefore some beam need to be added. All the blue highlighted lines are the beams that

need to be improved. Here, we improve on the back roll bar, the base of driver seat, the side

impact tubular member, and the support between the roll bar and the engine cage.

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DESIGN 2

Figure 15: Isometric view of design 2

From the figure above, all the modification in design 1 has been done. However, on the

front roll bar the height need to be increase to provide space for steering department to place

their steering, and the shaft needed for the system. As the front roll bar is increase the back roll

bar must also increase in order to fulfill requirement by faculty that the effective roll bar must

extend 50mm around the driver helmet.

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DESIGN 3

Figure 16: Isometric view of Design 3

As seen in the figure above for the 3rd design, the improvement is less. The blue lines are

only on the base of the driver seat. We decided to change the driver seat support to ease the

fabrication process by according to Design for Assembly (DFA). Before the modification, the

inclined bar will be welded on the sharp corner in which, precision to cut the bar according to the

angle is difficult due to limited of machinery in the workshop. If the angle of the bar is not

precise the weld of the joint will not enough to withstand load thus the structure will fail.

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DESIGN 4

Figure 17: Isometric view of design 4

The figure above shows the final improvement that we made. Two long beam is added on

the base of the chassis to support the power engine at the rear. Front chassis will support the

steering, braking and suspension system. On the front side, few vertical beams is added to enable

shaft placement of suspension and the same time avoid force deformation acting from vertical.

Supports are also added at the rear to help in supporting the back roll bar and the engine cage.

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FINAL DESIGN

Figure 18: Final Design

The figure shows our complete of final design. After went through a number of

revolution, modification of support and cooperation with other department, we believe this is the

most reliable, stable and fulfill others functional department.

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4.4 Parametric Design

Figure 19: Parametric Design 1

Top view Front view

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Side view

Isometric view

Figure 20: Parametric Design 2

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Top view Side view

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Front view Isometric view

Figure 21: Parametric Design 3

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Top view Side view

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Front view Isometric view

Figure 22: Parametric Design 4

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Top view Side view

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Front view Isometric view

4.5 Analysis of Chassis

Analysis on the chassis must be done in order to identify the strength of the structure in

various conditions such as during static condition, moving at particular velocity, impact

condition and many more. During each condition, the strength of material is differing from each

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other. The strength of the structure can be determined by using CATIA or ANSYS. By using

CATIA, the analysis is carried out through numerical technique of finite element method (FEM).

FEM encompasses methods for connecting many simple element equations over many small

subdomains, named finite elements. In order to approximate a more complex equation over a

larger domain where using the manual calculation is impossible, these finite element method is

applied. Therefore to ease the determination of stress acting on chassis frame, this method can be

used such that Von Misses stress will be induced in the structure is determined and next can be

compared with the yield strength of materials. Besides that, we can also obtain the translational

displacement vector.

There are numbers of test that we perform on our chassis frame such as:

1. Side impact test

2. Front impact test

3. Clash torsion test

4. Clash torsion frontal moment test

5. Chassis acceleration test

6. Mass and center of gravity test

7. Mounting test

8. Complete test

1. Side Impact Test

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Figure 23: Von Mises stress side impact

Figure 24: Translational displacement vector side impact

The figure 23 above shows how the load acted on particular point on the structure and

amount of stress induced. In this analysis we let 700N loads acted on the side of the tubular

member of the chassis. The yellow arrow on the diagram shows the point where the load is acted

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on. As the force is applied, the Von Mises stress will be induced accordingly to the loads acted

on. The scale on the side of the figure with colour palettes shows the amount of Von Mises stress

that had been induced in the structure. In the same time, on the chassis skeleton the effect of

deformation can be seen clearly and visualization of colour palettes as same as on the scale

appear. To achieve a successful test analysis the maximum Von Mises stress located at bright red

scale must lower than the yield strength of material.

From the scale, the red colour which is the top scale is 3.22× 106 N/m2. This is the

maximum amount of the stress induced in the structure when 700N. Comparing this value to the

yield strength of the material which is 5.0×108 N/m2, the maximum Von Mises stress induced is

very low compare to the yield strength of materials. This shows that the chassis are strong

enough and will not fail when force acting on the side of the frame is as required in the

specification which is 700N.

Figure 24 shows the translational displacement vector when loading is acting on the side

of the chassis. This figure will visualize the field pattern which represents a vector field quantity

equal to the variation of position vectors of material particles of the system as a result of loading.

As the force of 700N is acted on the point in the figure, the red visualization shown at the chassis

will translated about 3.62mm from its original position. This is the maximum value of

translational displacement of the chassis. The further the area from the point loading, less

translational will occur on that particular area of tubular member. The least translational occur on

the structure is 0.362mm according to the blue colour variation on the figure. The colour field

pattern on the chassis is translated accordingly to the value on the scale of the colour variation on

the side of the figure.

As a conclusion, the side impact test is successfully done due to low value of maximum

Von Mises stress acting on the side of the chassis is achieved and the translational displacement

vector is too small.

2. Front Clash Test

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Figure 25: Von Mises stress front clash

Figure 26: Translational displacement vector front clash

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Figure 25 shows the Von Mises stress acted upon clash happen at the front skeleton of the

chassis. The condition of the chassis is static. In this test we let 700N of load acted on the point

shown by yellow arrow in the figure. Therefore the maximum Von Mises stress obtained from

this test is the 4.085×106N/m2. Comparing with the yield strength of the material which is 5.0×

108N/m2, the Von Mises stress that induced in the structure are much lower than the yield

strength of material. According to the analysis figure, the stress will occur on the frontal area

with at with the bright red colour. But, however we can see clearly that the colour variation is not

obvious. The minimum Von Mises stress is induced in the structure is only 707.56N/m2.

The figure 26 shows the translational displacement vector of front clash. As we can see in the

figure when we let 700N force act on front, at front edge of the chassis the colour turns red, at

this area the translational displacement is at maximum which is 4.21mm from its original point.

On the orange area the translation displacement is 3.79mm from its original point. The colour

field pattern changing as the area gets further from point loading and the translational

displacement also reducing. There is some area with no translational displacement in when the

colour is same as the bottom scale of blue. This show that these areas are not affected at all when

the force is applied.

As a conclusion, the front clash analysis successfully achieve a good result in which the

structure will not fail when the required force is applied and only little movement will occur on

beam at edge of front chassis.

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3. Clash Torsion Test

Figure 27: Von Mises torsion

Figure 28: Translational displacement torsion

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Figure 27 shows torsional force acted on the front of the chassis. The point loading is placed

at the edge of front chassis to determine the stress induced in the structure. The loading is a

torsion load of 700N acting in static condition. As we run the analysis, the Von Mises stress is

induced and it starts to show the colour pattern thus comparison can be made. The highest stress

that induced is 6.44×106N/m2. Comparing with yield strength of material which equal to 5.0×

108N/m2, the Von Mises stress is lower. The structure will twisted in the direction of force acting.

No deformation will occur. The minimum Von Mises stress is 1.91×103.

Figure 28 give the value of translational displacement on the point loading. On the red area

which displacement is at maximum, the displacement is 6.06mm from the original position. The

orange area, the displacement occur is 5.46mm. Wheareas on the yellow area, the displacement

is 4.85mm from its original position. If we can see the displacement of is happen on the other

side of the point loading, it is not impossible because the drawing might have some error in

which the length is not perfectly same on both side.

As a conclusion, the test is successful since the induced stress is less than the yield strength

of material plus very small displacement occurs on the chassis structure. The structure is safe

enough and suitable for installation of suspension, braking, and steering system at the front

skeleton due to stability of the front chassis from torsional moment acted upon it.

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4. Clash Torsion Frontal Moment Test

Figure 29: Von Mises clash torsion frontal moment

Figure 30: Translational displacement clash torsion frontal moment

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Figure 29 shows when the clash happens in the form of twisting the chassis in the

direction of the yellow round arrow in the figure. In this we let the arrow carry 700N acting

while the side of the chassis is clamp so that it can resemble the attachment of suspension and

other component. These clamps also have loading acting. It is in the static condition As we run

the analysis, the maximum Von Misses induced is 1.36×107N/m2. Even though it is the

maximum value of stress induced it is much lower compared to yield strength of steel which is

5.0×108N/m2. The minimum stress induced is 9443.76N/m2.

Figure 30 shows the translational displacement of the chassis skeleton when the followed

condition is occur. The maximum translational displacement is happens only on one side of the

chassis in which the red area is shown the figure. The value of the translational displacement is

quite high compared to other test; it is around 40.7mm from original position. The minimum

translational displacement is 4.07mm and there are some areas which are not affected or move

from original position.

From the result of analysis obtain, we can conclude that the moment acted upon structure

may not cause the chassis to fail. This is due to the amount of stress induced when the desired

force acting on the particular position is not exceed the yield strength of the material and

consequently only small translational displacement occur. The factor of safety secured.

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5. Chassis Acceleration Test

Figure 31: Von Mises acceleration

Figure 32: Translational displacement acceleration

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Figure 31 shows the Von Mises acting on the chassis during acceleration at 30m/s2. The point

loading can be clearly seen by the four arrow acted on the back roll bar. Each arrow gives 30m/s2

on the point shown. By finite element method, it helps us to determine the result of the analysis

which is also in terms of the Von Mises stress. Therefore, the maximum stress achieve is 4.22×

106N/m2 in which this value can be obtain from colour field pattern at the right side of the figure.

As usual it is still less than the yield strength of the material used thus we can say that it is not

deformed under the stated acceleration condition.

In order to identify the translational displacement occur at this condition, we may observe the

figure 32 above. The maximum translational displacement occurs on the top of the roll bar with

the value of 9.72mm. The region is shown clearly on the figure where the red field pattern is

seen. Whereas, the minimum displacement is 0.972mm .

Here, we can conclude that the structure is stable and be able to withstand the moving

condition at stated acceleration without fail. Once again, the safety factor is secured. The back

support that had been modified through 4 design shows it function. The analysis is success.

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6. Mass and Center of Gravity Test

Figure 33: Mass and center of gravity.

Center of Gravity (COG), is the point at which all of the weight of an object appears to be

concentrated. If an object rotates when thrown, the center of gravity is also the center of rotation.

When an object is suspended so that it can move freely, its center of gravity is always directly

below the point of suspension. An object can be balanced on a sharp point placed directly

beneath its center of gravity. It is important for automobiles and trucks to have their centers of

gravity located close to the road, because a low center of gravity gives them stability. Our center

of gravity is located 239.025mm from the ground. At the center of viewed from front and center

if view from the side view.

Mass is needed to calculate the inertia of the chassis and the force needed to stop the

moving car, therefore the mass of chassis must be included in the calculation for other

department to determine their parts of research.

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7. Mounting Test

Figure 34: Von Mises mounting

Figure 35: Translational displacement mounting

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Figure 34 is the Von Mises induced in the structure at static condition while all bracket

for suspension is mounted. The chassis will be held by the shaft, therefore it is important to

identify stress that can be withstand by the chassis frame when all component is mounted on it.

We using the Von Mises stress to compare with the yield strength of material. By applying 100N

of each clamp, the analysis can be run and automatically the visualization of colour field pattern

is achieved. The maximum Von Mises achieve is 1.047×108N/m2 and the minimum of 9.68N/m2.

The maximum Von Mises is lower than 5.0×108N/m2 (yield strength of steel). The chassis pass

the mounting analysis. It able to withstand all forces from systems acted on it.

The maximum translational displacement in the figure 35 is 96.8mm from its original

position. It is decreases gradually downward the scale of the colour field pattern until the

displacement is zero and the most bottom of blue. The red area is not as much as previous test

therefore it unable to be seen clearly.

However the analysis pass successfully due to Von Mises stress lower than yield strength

and also the maximum translational displacement value is still consider as small.

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8. Complete Test

Figure 36: Von Mises complete test

Figure 37: Translational displacement of complete test

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Figure 36 shows the complete test of the chassis at the static condition. Here the driver

weight is also included together with the mounting of all system required and the test that had

been done for all condition before. The chassis have many forces acted on various positions. By

considering the maximum value of Von Mises stress we can easily compare with the yield

strength such that the maximum Von Mises stress is 2.07×107N/m2. The yield strength is

relatively higher than Von Mises stress thus the structure is reliable to be used. The red area is

too small on the edge of the chassis as shown in the above figure.

The figure 37 shows the complete translational displacement of the chassis in which the

maximum value is 13.1mm from the original position. This displacement occurs on back the roll

bar. All the forces acting can be seen in this figure as it indicated by the yellow arrow. The

visualization of colour field changes unevenly throughout the chassis frame. But however the

colour can be matched to the scale thus obtaining all point of translational displacement.

The conclusion is the complete analysis test is the most practical as it consider all the

forces acted on the chassis including the drivers weight but yet it is still a successful analysis

because the maximum Von Mises is less than the yield strength material and the translational

displacement is not large.

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5.0 DETAIL DESIGN

Figure 39: Detail Dimension of Final Design

Top viewSide view

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Isometric view

Front view

5.1 EXPLODED VIEW

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Figure 40: Exploded view

5.2 BILL OF MATERIAL

No Component Quantity Sources Material Price per unit (RM)

Total price

01 Base length side bar

2090

2 Buy Steel 10.40 20.80

02 Base length center bar

2040

2 Buy Steel 10.10 20.20

03 Base width side bar 130

12 Buy Steel 0.70 8.40

04 Base width center bar

150

6 Buy Steel 0.80 4.80

05 Front roll bar 1080

1 Buy Steel 5.40 5.40

06 Back roll bar2500

1 Buy steel 12.40 12.40

07 Back roll bar support

1000

2 Buy Steel 5.00 10.00

08 Back roll bar engine

support 805

2 Buy Steel 4.00 8.00

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09 Front roll bar support

666

2 Buy Steel 3.30 6.60

10 Upper front Side 682

2 Buy Steel 3.40 6.80

11 Upper back side 662

2 Buy Steel 3.30 6.60

12 Front & back central 460

5 Buy Steel 2.30 11.50

13 Vertical short bar

270

12 Buy Steel 1.40 16.80

14 Mounting bracket upper

16 Buy Steel 1.20 19.20

15 Mounting bracket lower

16 Buy Steel 1.20 19.20

TOTAL: RM 176.70

6.0 DISCUSSION

From our progress in designing the chassis, we have certain limitation

in developing the chassis frame. This clogged our designing from what idea

that we already have because of limitation. Firstly, we lack of exposure in

designing component by using software. In designing we use CATIA software

but it is still new for us. Therefore, we are unable to perform any complex

parts in the chassis frame. Plus, we having hard time to study about this

CATIA software with ourselves without further guide from expert. We have to

explore functional of all methods in software that works with experiment

samples and that take long time to master the CATIA software skill. Besides,

we also lack of handcraft skill, specifically in welding so we have to develop

the chassis frame based on our ability. We lack of workshop practice which

result in lacking in the knowledge to develop and built the chassis.

We also consider the cost because we have limited budget which we

cannot afford to exceed the budget and have to create our chassis which our

very own skills and the tools that are provided by the faculty. Even though,

we lack of skill, we cannot afford to hire someone to craft our chassis.

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Therefore we have to be a quick learner and craft our very own chassis.

Since we are limiting the cost, we cannot afford to buy fine material such as

titanium. Hence, we have to use the alternative ways by using the materials

provided that is hollow rectangular mild steel.

Next is limitation due to technical specification, we are only limited to

structural space frame chassis type only. Therefore we cannot create

monocoque type chassis. From the technical specification, we are not

allowed to use any alloy steel having at least one alloy element the mass

contain of more or equal to 5%. Due to safety regulation, our chassis must

also equipped with an effective roll bar that extend 50mm around the drive’s

helmet and must be capable of withstanding a static load of 700N which

applied in a vertical, horizontal or perpendicular direction without deforming

and also extend in width beyond the drive’s shoulders when seated in normal

driving position. The technical specification also limiting us from exceeding

the minimum wheel base of 1000mm and 1500mm maximum. Our vehicle

also limited by length and width of 2500mm and 1400mm respectively.

Hence, because of this specification, our department must also provide

space for other department to install their component without exceeding the

technical specification.

We also have limited time in developing the chassis because to draw

the particular design by using computer-aided drawing in CATIA is time

consuming with our current skills. We also had a limited time to discuss

which is only two hour a week. It is also time consuming to make adjustment

on our chassis base on modification demand from other department which

keep on changing.

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7.0 CONCLUSION

The objectives of this project had been successfully obtained. All

the design and analysis for chassis component had been conducted

properly in order to maintain chassis reliability and fulfill demand of

other department. The designated chassis also has followed the

requirement as stated by faculty. Besides, this project also allow

student to explore the using of CAD software (Computer-Aided

drawing). The most important thing is all students will develop their

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soft skills such as leadership, teamwork, and passion during

accomplishment of this project.

8.0 REFERENCES

1. http://www.mechanicalengineeringblog.com/tag/conventional-

frame/

2. http://bieap.gov.in/Pdf/automobilechasis.pdf

3. http://www.colorado.edu/MCEN/MCEN4173/chap_01.pdf

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4. http://catiadoc.free.fr/online/estug_C2/estugbt0503.htm

5. http://www.learnengineering.org/2012/12/what-is-von-mises-

stress.html

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

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