Graduation Design (Dissertation) of Wuhan University of Technology

Design and kinematic analysis of the suspension of a compact SUV

School: International Education College

Specialty amp; Class: Automobile Engineering gj1304

Student name: Yu Fan

Tutor: Yu Chenguang

Statement of Originality

I solemnly declare that the thesis I submit is a piece of writing I completed independently based on my own research under the guidance of my supervisor. Except for the quotations, this paper does not include any writings published or completed by other individuals or groups. I am fully aware that the legal consequences of this statement are borne by me.

Signature of the author:Yu Fan

Date:2017.5.30

Copyright Letter of Authorization to The Dissertation

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Signature of the author: Yu Fan Date:2017.5.30

Signature of the tutor: Date

Abstract

In this paper ,according to the actual, the suspension structure of the compact SUV is designed, and its kinematics analysis is carried out by using the ADAMS/CAR software. Then, the two-degree-of-freedom vehicle vibration system dynamics model is established to analyze the ride comfort. This paper first introduces the development of the suspension system at home and abroad. Then, based on the structure and arrangement requirements of the suspension of the compact SUV, the suspension type is selected according to the advantages and disadvantages of various suspension forms, and the suspension system is designed. According to the preliminary design results, the suspension system is modeled in ADAMS/CAR and the kinematics simulation of the suspension is carried out. According to the simulation results,the wheel positioning parameters and track parameters are within a reasonable range of changes with the wheel up and down. Finally, the car's ride comfort is analyzed,and the results meet the requirements.In this paper, the basic idea of the matching of the front McPherson suspension and the rear multi-link suspension is proposed, and the basic direction of the design of the compact SUV suspension is determined. The kinematics analysis and ride comfort analysis has certain practical significance for improving the overall performance of compact SUV, and has certain reference value for the suspension design of automobile enterprise.

Key Words: Compact SUV;Suspension;Structural design;ADAMS/CAR; Kinematics analysis

Contents

Chapter 1 Introduction 1

1.1 Research background and significance 1

1.3 Content of the study 3

1.4 Expected target 3

1.5 Brief summary of this chapter 4

Chapter 2 Structural analysis and design of suspension 5

2.1 Suspension system overview 5

2.1.1 The composition of the suspension 5

2.1.2 Suspension function 5

2.2 Suspension classification 5

2.2.1 Characteristics of non-independent suspension 6

2.2.2 Features of independent suspension 6

2.3 Selection of front and rear suspension structure 7

2.4 Suspension design requirements 10

2.5 Determination of main parameters of front and rear suspension 11

2.5.1 The main technical parameters 11

2.5.2 Selection of wheel alignment parameters 11

2.5.3 The frequency of the suspension 14

2.5.4 Static deflection of suspension 14

2.5.4 Dynamic deflection 15

2.5.5 Stiffness of suspension 16

2.5.6 Elastic characteristics of suspension 16

2.5.7 Roll angle stiffness of suspension 17

2.6 The design of damper 18

2.6.1 Selection of damper 18

2.6.2 The design of damper of the front suspension 18

2.6.3 The design of damper of the rear suspension 22

2.7 The design of elastic elements 23

2.7.1 Design of coil spring of front suspension 23

2.7.2 Design of coil spring of rear suspension 25

2.8 Design of guiding mechanism 27

2.9 The design of horizontal stabilizer bar 29

2.10 Summary of this chapter 30

Chapter 3 The establishment of suspension model 31

3.1 ADAMS analysis software and its characteristics 31

3.2 The establishment of the model of the front suspension 31

3.2.1 Analysis of front suspension model 31

3.2.2 The establishment of the model of the front suspension 33

3.3 The establishment of the model of the rear suspension 35

3.3.1 Analysis of rear suspension model 35

3.3.2 The establishment of the model of the rear suspension 35

3.4 Summary of this chapter 37

Chapter 4 Suspension kinematics simulation test 38