MMSD Sample Proposal 3

7/31/2019 MMSD Sample Proposal 3

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Proposal for The 2003 Formula SAE

Chassis and Analysis Team

SUBMITTED TO

Senior Design Project Committee

Department of Mechanical Engineering and Mechanics

Drexel University

ENTITLED: Land Dragon 2003 Design, Analysis of a Formula SAE Chassis Systemand Fabrication of a Chassis Test Rig.

PROJECT NUMBER:

TEAM MEMBERS MAJOR>>>>>>>>>>>>>>>>>>>>

Submitted in partial fulfillment of the requirements for Senior Project Design

November 26th, 2002


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Abstract

Each year at Drexel University students design and build a car to race in the

Formula SAE design competition, which is held in Pontiac, Michigan. This car must

meet a multitude of design constraints as dictated by the FSAE rules1. Our car, the Land

Dragon, has participated in the competition for the last eleven years. Unfortunately, the

Land Dragon has suffered from many limitations namely excessive weight and structural

design imperfections of the chassis, which have infringed on its performance in the past.

The design and analysis of the chassis for the Drexel Land Dragon is an integral

part of the overall team project. Each year a brand new car is built, from ground up, to

compete against cars from over one hundred other schools in the Formula SAE

competition. Along with the importance of the design comes the analysis; this years

team will be one of the first to complete an in-depth finite element analysis of the chassis.

Unlike in previous years, techniques to improve the weight, torsional rigidity, and the

overall drivability of the car will be implemented. By taking advantage of three-

dimensional modeling we will be able to fully analyze the problem areas of the chassis

and construct an optimal design for future competitions. With the knowledge gained

from the Finite Element Analysis (FEA), a chassis design for the 2004 car will be

completed utilizing the engine as a load-bearing member of the frame. Also by using

state of the art materials and monocoque processes to strengthen and lighten the chassis.

The design will still comply with each of the explicit specifications of the other teams

(engine team, suspension team, etc.) as well as the rules of the competition.

To further enhance future teams success, our team plans to investigate, design

and construct a test rig in order to optimize the structural capabilities of a chassis. The

test rig will deliver numerous forces over a wide range of angles, directions and

magnitudes to a chassis. Along with applying these forces it will have the capability to

measure and output the stress and strain on key structural members in order to calculate

the overall torsional rigidity. To accommodate any future chassis designs, the test rig

will be extremely versatile. After the construction and static testing of the chassis, ourcomputer analysis will be compared with the test rig in order to give real data

comparison. This will be a huge advantage in future chassis design and analysis.

1 Rules can be accessed at http://www.sae.org/students/fsaerules.pdf1] Due to their length (93 pages) theywill not be submitted with this proposal.


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Table of Contents

i. Abstract Page i

I. Introduction

A. Problem Background Page 1

B. Problem Statement Page 2

C. Constraints of the Project Page 2

II. Statement of Work

A. Method of Solution Page 3 - 4

B. Alternative Solutions Page 5

III. Project Management Timeline (Gantt Chart) Page 5

IV. Economic Analysis Page 6

V. Environmental Impact Page 7

VI. References Page 7

Appendices

1. Material Constraints Page 8

2. Project Timeline

a. Gantt Chart Fall Term Page 9

b. Gantt Chart Winter/Spring Term Page 10

3. Three-dimensional Representation Page 11of Chassis and Test Rig

4. Team Background Page 12-16


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I. INTRODUCTION

Problem Background

In order to build a successful car, we must first look at itsmost fundamental

component, the chassis. It is the goal of Drexel Universitys Formula SAE team to

achieve a higher level of accomplishment at the design competition, to accomplish this

the car will require a chassis design that has been computer generated and analyzed; also

it must be fabricated and structurally tested before the competition this spring.

Using the experiences and research of previous teams as a guide, while also

taking into account their shortcomings and advances, we are prepared to confront the task

at hand. To ensure a successful Formula SAE car this year, we intend to do extensive

computer aided modeling, including FEA, as well as a number of physical tests using the

newly constructed test rig to test this years chassis. A chassis test rig has never been

implemented before by any previous team, fabrication of this test rig will give us an

advantage over previous years by being able to dynamically measure the forces acting on

the physical chassis. With this knowledge we will be able to focus our attention to the

critical areas of the chassis, and insure future success through design evolution.


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Problem Statement

The goal of our project is to design and fabricate a three-quarter-scale formula

style car that would appeal to the weekend autocross racer. The car is built to the

requirements specified by the Society of Automotive Engineers (SAE) and conforms to

the racing regulations set forth by the Sports Car Club of America (SCCA). Specifically,

our intention is to design, analyze and fabricate the chassis, as well as designing and

constructing a chassis test rig for the racecar. We also plan to generate a design for the

2004 Land Dragon chassis, using cutting edge materials and processes. The

specifications dictated by Formula SAE are meant to challenge students knowledge,

imagination, and creativity. Successful completion will require continuous

communication and interaction with the other teams that are working simultaneously on

the car. In the end, we will have designed, analyzed, fabricated, and tested a complete

chassis system that meets our deliverable deadlines and fundamental design goals.

Constraints on the Project

The number of solutions to our project seems almost limitless. However, a

number of restrictions exist that will limit the number of possible designs for the chassis.

The paramount set of constraints comes from the 2003 Formula SAE rules. The Formula

SAE rules regulate the size and wall thickness of the steel tubing for most of the chassis,

leaving little room for originality (Appendix 1). However, upon approval of safety

equivalency calculations, other materials and geometry may be utilized.

One of the more important demands that the power train team has imposed on us is that

the engine must be easily accessible for maintenance, but in our design the engine is

acting as a structural component. The test rig that we are building has a number of

constraints as well, it has to be versatile and still output useful data such as the torsional

rigidity of the chassis.


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II. STATEMENT OF WORK

Method of Solution

The current working chassis design is more evolutionary than revolutionary;

however when the design for the 2004 chassis is set we will have much more freedom

from the current design, and will be able to implement many new ideas. We will still be

using the experience that has been gained from the past years cars as this will give us a

good basis for a new design and will allow us to build past knowledge. We have four

major tasks that need to be completed this year:

1. Model the Current 2003 Chassis Design:

In order to successfully accomplish our overall team goals the team will work

concurrently with the Suspension and the Powertrain teams to support the design criteria.

A Pro-E model has been produced to act as a basis for the design, however the final

design for the 2003 chassis design will be modeled in SDRC I-DEAS Master Series 9

allowing for a seamless integration into the programs FEA package.

2. Conduct a Finite Element Analysis on the Chassis Design:

Since construction on this years chassis has already begun, we hope to validate the

structural design through a detailed FEA analysis to ensure that our geometry and welds

will be adequate. The FSAE team will be performing the majority of the work required

for the chassis fabrication with the exception of the bending of some key geometry; this

should save a considerable amount of money.

3. Design and Construct a Chassis Test Rig:

Once the chassis is assembled static and dynamic testing will commence and our

results will then be compared to the theoretical results given in the FEA analysis. Upon

completion of FEA analysis it will be important to test the actual chassis under real

driving conditions. These conditions will be applied via the test rig. The test rig will

have the ability to apply forces to the chassis members to simulate turns, stops, and

accelerations. Using accurate strain gauges placed in critical points throughout the

chassis structure, we will compare between FEA analysis and actual reactions of the

materials. It is critical that the manner in which the forces are applied as well as the


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magnitude at which they are applied represent actual driving conditions. These force

characteristics must be researched extensively in order to create the most accurate

possible rig for an FSAE car of varying sizes. The basic design will be a modular four

point rig, with three posts to hold the chassis to the fixture, and the fourth post will be the

actuator which will apply the forces directly to the chassis. (See Appendix 3 for

illustration.)

4. Design a New Chassis for the 2004 Competition:

For the basis of the 2004 chassis the engine will be utilized as a load-bearing member

of the chassis. This will involve mating the front section of the chassis to the front of the

engine block and the rear section of the vehicle to the rear of the engine block. The

engine of the car is from a Honda motorcycle; Hondahasbased their chassis design for

motorcycle using the engine block as a stressed member. This adds torsional rigidity

while reducing the overall weight of the motorcycle by eliminating cross bracing and

other structural tubes in the frame. This same reasoning will be utilized on the 2004

design of the chassis. Using these same techniques we will able to effectively reduce

weight and increase the strength of the chassis, both of which are at a high priority.

The suspension team has provided the suspension mounting points that we will

incorporate into this years design; for the 2004 design we will use this years geometry

as a basis and future teams can modify it as they see fit based on their needs. The

mounting points on the engine block are the determining factor for the design of the rear

box, while information from the Powertrain team will implement further design

constraints.


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Alternative Solutions

Material selection is one of the more important factors in our overall design. An

essential goal is to make a lightweight, rigid chassis; thus making material selection

imperative. Possible alternatives would be the selection of titanium or aluminum for use

in either the front of the car which would help to evenly distribute the weight ratio

between the front and rear of the car. Other FSAE teams have, despite the obvious high

cost, attempted to produce an Aluminum or Titanium chassis test rig. Instead of

constraining three sides with no movement, all four points could have actuators placed on

them but this will incur a much larger cost as well as creating design issues. An

alternative to using actuators, a more simplistic method could be used but this will not

produce the accuracy that is required. The dimensions of the chassis are variable as well

as the structural geometry. The length of the wheelbase can be a variable as well, which

could make a significant impact on the overall performance of the car at its completion.

Alternative materials will be incorporated into the design of the 2004 chassis,

such as materials with equivalent ultimate strength and bending modulus as the specified

steel from the FSAE rules. The selection of these alternative materials will be

determined by evaluations of their material properties. Reducing the overall weight of

the vehicle will bring the front to rear weight ratio closer to an ideal value of 50/50.

III. Project Management Timeline

Appendix 2 are Gantt charts illustrating the time frame in which we plan on finishing the

modeling analyzing and fabrication of the chassis for the Land Dragon 2003. Appendix

2a is the Gantt chart for the Fall Term. The completion date for the chassis is January

12th 2003. Soon after the chassis is complete we plan to have the test rig designed and

fabricated, in order to perform the necessary testing. Our timeline will coincide with the

other groups working on the FSAE project, which should enable the team to have a

rolling chassis for testing in January.


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IV. Economic Analysis

The concept of the cost and manufacturing analysis in the FSAE competition is to have

each team obtain an accurate estimate of the manufacturing cost of the car in limited

production, utilizing lean manufacturing concepts where applicable. A detailed cost

report with an itemized list of all expenses will be performed at the end of the

competition. As stated in the rules, the entire prototype is not to exceed $25,0002.

Using money raised through various sources including outside sponsorship, Student

Activities Fund (SAFAC) and the College of Engineering. The chassis and body system

of the car has been relatively inexpensive in the past. Many of the services that we use,

such as welding and tube bending, have been donated or provided to us at a minimal cost.

Utilizing the composites may drive the price of the systems higher, but it could lead

Drexel to have greater success. We will have to continue to rely on generous donations

of materials and services to keep the cost of the chassis low. The test rig was not

originally in this years budget, but we feel that it is a worth while investment for this

year and for the future teams. Depending on the material type used in the design, the test

rig could turn out to be relatively expensive; however we are hoping for some helpful

companies to come to our aid. (Tentative budget not including the test rig, we are waiting

on certain catalogs to arrive.)

Budget

Chassis Test RigTube Dimensions Cost Tube Dimensions Cost

1 X .049 $45.12 3 X 6(Bosch Tube) $1,240.00

1 X .035 $79.20 2 X 4(Bosch Tube) $415.00

1 X .035 (Square) $74.88 Steel Tube $200.00

5/8 X .058 $59.57 Miscellaneous Parts $100.00

5/8 X .049 $29.04 Actuator $560.00

1 X .065 $56.24 Sensors $345.00

1 X .095(Chromoly) $46.80 DAQ Software $200.00

Steering Rack Tube $24.02

Miscellaneous Parts $40.00

Total $454.87 $3,060.00Overall Project Cost $3,514.87

2 Rules can be accessed at http://www.sae.org/students/fsaerules.pdf [1] Due to their length (93 pages) theywill not be submitted with this proposal.


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V. Environmental Impact

The major environmental issue is the disposal of scrap metal tubing. When cutting tubes

for the chassis we produce small lengths of tubing. Tubing that is too small to be used in

future construction is collected and recycled. There is no other substantial environmental

impact foreseen as a result of our project.

VI. References

[1] Formula SAE, 2001 FSAE Competition Rules,

http://www.sae.org/students/fsaerules.pdf


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Appendix 1: Material Constraints

Front and Main Roll Hoops

Material Outside Diameter x Wall Thickness

Round Mild Steel Tube (SAE

1010, 1015, 1020, 1025)

25.4 mm (1 inch) x 2.4 mm (0.095 inch)

Side Impact, Roll Hoops Bracing, Front BulkheadMaterial Outside Diameter x Wall Thickness

Round Steel Tube 25.4 mm (1 inch) x 1.65 mm (0.065 inch)

Alternative Tubing - Requirements

Material Minimum Wall Thickness

Round Steel Tubing (Front

and Main Roll Hoo s

2.1 mm (0.083 inch)

Steel Tubing (Roll Hoop

Bracing, Bulkhead)

1.65 mm (0.065 inch)

Steel Tubing (Side Impact) 1.25 mm (0.049 inch)

Aluminum Tubin 3.175 mm 0.125 inch


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Appendix 2a: Project Timeline (Fall Term)


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Appendix 2b: Project Timeline (Winter/Spring Term)


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Appendix 3: Three-dimensional Representation

of Chassis and Test Rig

Documents

MMSD Sample Proposal 3