CAR CHASSIS DESIGN

Car Chassis Design



Table of Contents

1.0 introduction3

1.1 background research3

1.2 brief4

2.0 market research4

2.1 costumer survey4

3.0 design specification5

3.1 function1 (performance) (look at design specification)5

3.2 function2 (environment) (look at design specification)6

4.1 concept generation6

4.1.1 features (see ''analysis for the design features'' attached)7

4.1.2 analysis (see ''analysis for the design features'' attached)7

4.2 concept evaluation (see ''best concept selection'' attached)8

4.2.1 need and suitability (see ''best concept selection'' attached)9

4.2.2 design selection (see ''best concept selection'' attached)10

4.3 result and reflection (see ''best concept selection'' attached)11

4.4. Comparison12

Car Chassis Design

1.0 introduction

The automotive chassis is tasked with holding all the components together while driving,and transfering vertical and lateral loads, caused by accelerations, on the chassis through the suspension and two the wheels. Most engineering students will have an understanding of forces and torques long before they read this. It is suggested that the reader has a good understanding of the concepts of axial forces, shear forces, bending, torsion, angular and normal deflections, and finally mass moment of inertia (Fahrner, 1998, 48-53). The key to good chassis design is that the further mass is away from the neutral axis the more ridgid it will be.

1.1 background research

The perfect chassis is a large diameter thin walled tube.

In order to understand this you should have a solid grasp of statics and deflection. The Automotive chassis has two main goals.

Hold the weight of the components

To ridgidly fix the suspension components together when moving

The first item is an easy design solution and is also the basis of the original chassis designs that were taken from horse drawn carriages (Fahrner, 1998, 48-53). One of the most effective shapes for supporting point loads fixed at two ends is an I-Beam, a box tube, or a C-Beam.

1.2 brief

When cornering torques are applied to the chassis it causes it to twist. The engineernig solution for this torsion problem is simply a tube. Understanding of basic mechanics, the further the material is away from the center of application of the torque, the more resistive it is to deflections to the power of four (Grenzeback, 2005, 33-55). One thing that competition designs normally quote is torsional ridgity in Netwon Meters/Degree of twist. Not all chassis torsion tests are the same but all give a general idea of how stiff the chassis is. The stiffer the chassis the more cornering torque it can handle with less effect on suspension geometry.

2.0 market research

Low Cost Chassis Systems Market: Estimated Market Share of Low-cost car Manufacturers (World), 2015

Fig 1: market research

2.1 costumer survey

Writing solid and unbiased surveys may seem like a daunting and unapproachable task. However, it is not as overwhelming as one may think! Creating well structured, simply written questions will help in collecting valid survey responses (Grenzeback, 2005, 33-55). An important goal as a survey author is to construct clear, direct questions and answers using the language that survey participants will understand. While there are no set rules on the wording of these survey questions, there are some basic principles that do work to improve the overall ...