The Shock Absorber Handbook

Contents

Preface to Second Edition

Acknowledgements

1 Introduction

1.1 History

1.2 Types of Friction

1.3 Damper Configurations

1.4 Ride-Levelling Dampers

1.5 Position-Dependent Dampers

1.6 General Form of the Telescopic Damper

1.7 Mountings

1.8 Operating Speeds and Strokes

1.9 Manufacture

1.10 Literature Review

2 Vibration Theory

2.1 Introduction

2.2 Free Vibration Undamped (1-dof)

2.3 Free Vibration Damped (1-dof)

2.4 Forced Vibration Undamped (1-dof)

2.5 Forced Vibration Damped (1-dof)

2.6 Coulomb Damping

2.7 Quadratic Damping

2.8 Series Stiffness

2.9 Free Vibration Undamped (2-dof)

2.10 Free Vibration Damped (2-dof)

2.11 The Resonant Absorber

2.12 Damper Models in Ride and Handling

2.13 End Frequencies

2.14 Heave and Pitch Undamped 1-dof

2.15 Heave and Pitch Damped 1-dof

2.16 Roll Vibration Undamped

2.17 Roll Vibration Damped

2.18 Heave-and-Pitch Undamped 2-dof

2.19 Heave-and-Pitch Damped 2-dof Simplified

2.20 Heave-and-Pitch Damped 2-dof Full Analysis

3 Ride and Handling

3.1 Introduction

3.2 Modelling the Road

3.3 Ride

3.4 Time-Domain Ride Analysis

3.5 Frequency-Domain Ride Analysis

3.6 Passenger on Seat

3.7 Wheel Hop

3.8 Handling

3.9 Axle Vibrations

3.10 Steering Vibrations

3.11 The Ride–Handling Compromise

3.12 Damper Optimisation

3.13 Damper Asymmetry

4 Installation

4.1 Introduction

4.2 Motion Ratio

4.3 Displacement Method

4.4 Velocity Diagrams

4.5 Computer Evaluation

4.6 Mechanical Displacement

4.7 Effect of Motion Ratio

4.8 Evaluation of Motion Ratio

4.9 The Rocker

4.10 The Rigid Arm

4.11 Double Wishbones

4.12 Struts

4.13 Pushrods and Pullrods

4.14 Motorcycle Front Suspensions

4.15 Motorcycle Rear Suspensions

4.16 Solid Axles

4.17 Dry Scissor Dampers

5 Fluid Mechanics

5.1 Introduction

5.2 Properties of Fluids

5.3 Chemical Properties

5.4 Density

5.5 Thermal Expansion

5.6 Compressibility

5.7 Viscosity

5.8 Thermal Capacity

5.9 Thermal Conductivity

5.10 Vapour Pressure

5.11 Gas Density

5.12 Gas Viscosity

5.13 Gas Compressibility

5.14 Gas Absorbability

5.15 Emulsification

5.16 Continuity

5.17 Bernoulli’s Equation

5.18 Fluid Momentum

5.19 Pipe Flow

5.20 Velocity Profiles

5.21 Other Losses

5.22 The Orifice

5.23 Combined Orifices

5.24 Vortices

5.25 Bingham Flow

5.26 Liquid–Solid Suspensions

5.27 ER and MR Fluids

6 Valve Design

6.1 Introduction

6.2 Valve Types

6.3 Disc Valves

6.4 Rod Valves

6.5 Spool Valves

6.6 Shim Valves

6.7 Valve Characteristics

6.8 Basic Valve Models

6.9 Complete Valve Models

6.10 Solution of Valve Flow

6.11 Temperature Compensation

6.12 Position-Sensitive Valves

6.13 Acceleration-Sensitive Valves

6.14 Pressure-Rate Valves

6.15 Frequency-Sensitive Valves

6.16 Stroke-Sensitive Valves

6.17 Piezoelectric Valves

6.18 Double-Acting Shim Valves

6.19 Rotary Adjustables

6.20 Bellows Valves

6.21 Simple Tube Valves

6.22 Head Valves

6.23 Multi-Stage Valves

7 Damper Characteristics

7.1 Introduction

7.2 Basic Damper Parameters

7.3 Mechanical Friction

7.4 Static Forces

7.5 Piston Free Body Diagram

7.6 Valve Flow Rates

7.7 Pressures and Forces

7.8 Linear Valve Analysis

7.9 Cavitation

7.10 Temperature

7.11 Compressibility

7.12 Cyclical Characteristics, F(X)

7.13 Extreme Cyclic Operation

7.14 Stresses and Strains

7.15 Damper Jacking

7.16 Noise

8 Adjustables

8.1 Introduction

8.2 The Adjustable Valve

8.3 Parallel Hole

8.4 Series Hole

8.5 Maximum Area

8.6 Opening Pressure

8.7 Area Coefficient (Stiffness)

8.8 Automatic Systems

8.9 Fast Adaptive Systems

8.10 Motion Ratio

9 ER and MR Dampers

9.1 Introduction

9.2 ER–MR History

9.3 ER Materials

9.4 ER Dampers

9.5 ER Controlled Valve

9.6 MR Materials

9.7 MR Dampers

10 Specifying a Damper

10.1 Introduction

10.2 End Fittings

10.3 Length Range

10.4 FðVÞ Curve

10.5 Configuration

10.6 Diameter

10.7 Oil Properties

10.8 Life

10.9 Cost

11 Testing

11.1 Introduction

11.2 Transient Testing

11.3 Electromechanical Testers

11.4 Hydraulic Testers

11.5 Instrumentation

11.6 Data Processing

11.7 Sinusoidal Test Theory

11.8 Test Procedure

11.9 Triangular Test

11.10 Other Laboratory Tests

11.11 On-Road Testing

Appendix A Nomenclature

Chapter 1 Introduction

Chapter 2 Vibration Theory

Chapter 3 Ride and Handling

Chapter 4 Installation

Chapter 5 Fluid Mechanics

Chapter 6 Valve Design

Chapter 7 Damper Characteristics

Chapter 8 Adjustables

Chapter 9 ER and MR Dampers

Chapter 10 Specifying a Damper

Chapter 11 Testing

Appendix B Properties of Air

B.1 Standard Properties

B.2 Effect of Temperature

Appendix C

Properties of Water

Appendix D

Test Sheets

Appendix E

Solution of Algebraic Equations

E.0 Introduction

E.1 The Linear Equation

E.2 The Quadratic Equation

E.3 The Cubic Equation

E.4 Quartic Equation

E.5 Fifth Order and Above

Appendix F

Units

Appendix G Bingham Flow

G.1 Bingham Flow

G.2 Bingham Flow Between Plates

G.3 Bingham Flow in a Circular Pipe

References

INDEX