High speed off-road vehicles : suspensions, tracks, wheels and dynamics / Bruce Maclaurin.

Format:

Book

Author/Creator:

Maclaurin, Bruce, author.

Series:

Automotive series (Wiley)

Automotive series

Language:

English

Subjects (All):

Off-road vehicles.

Physical Description:

1 online resource (336 pages).

Edition:

1st ed.

Place of Publication:

Hoboken, NJ : John Wiley & Sons, [2018]

Summary:

A concise reference that provides an overview of the design of high speed off-road vehicles High Speed Off-Road Vehicles is an excellent, in-depth review of vehicle performance in off-road conditions with a focus on key elements of the running gear systems of vehicles. In particular, elements such as suspension systems, wheels, tyres, and tracks are addressed in-depth. It is a well-written text that provides a pragmatic discussion of off-road vehicles from both a historical and analytical perspective. Some of the unique topics addressed in this book include link and flexible tracks, ride performance of tracked vehicles, and active and semi-active suspension systems for both armoured and unarmoured vehicles. The book provides spreadsheet-based analytic approaches to model these topic areas giving insight into steering, handling, and overall performance of both tracked and wheeled systems. The author further extends these analyses to soft soil scenarios and thoroughly addresses rollover situations. The text also provides some insight into more advanced articulated systems. High Speed Off-Road Vehicles: Suspensions, Tracks, Wheels and Dynamics provides valuable coverage of: * Tracked and wheeled vehicles * Suspension component design and characteristics, vehicle ride performance, link track component design and characteristics, flexible track, and testing of active suspension test vehicles * General vehicle configurations for combat and logistic vehicles, suspension performance modelling and measurement, steering performance, and the effects of limited slip differentials on the soft soil traction and steering behavior of vehicles Written from a very practical perspective, and based on the author's extensive experience, High Speed Off-Road Vehicles provides an excellent introduction to off-road vehicles and will be a helpful reference text for those practicing design and analysis of such systems.

Contents:

Cover

Title Page

Copyright

Contents

Series Preface

Acknowledgements

Introduction

Chapter 1 Tracked Vehicle Running Gear and Suspension Systems

1.1 General Arrangement

1.2 Transverse Torsion Bars

1.3 Coil Springs

1.4 Hydrogas Suspensions

1.4.1 Challenger MBT Hydrogas Unit

1.4.2 Measured Characteristics of a Challenger Unit

1.4.2.1 Spring Characteristics

1.4.2.2 Damper Characteristic

1.4.2.3 Differential Pressure Across the Damper Valve

1.4.2.4 Force/Displacement Loop

1.4.2.5 Flow Rig

1.4.2.6 Suspension Damping of a Multi‐Wheeled Vehicle

1.4.3 Temperature Effects

1.4.3.1 Two‐Stage Units

1.4.3.2 Counter‐Spring Units

1.4.4 Other Types of Hydrogas Suspension

1.4.4.1 Twin‐Cylinder Units

1.4.4.2 In‐Arm Units

1.5 Dampers

1.5.1 Hydraulic Dampers

1.5.2 Friction Dampers

References

Chapter 2 Vehicle Track Systems

2.1 Link Tracks

2.1.1 Single‐Pin Tracks

2.1.1.1 Dry‐Pin Tracks

2.1.1.2 Rubber‐Bushed Tracks

2.1.2 Double‐Pin Tracks

2.1.3 Rubber Track Pads, Road Wheels and Track Tensioners

2.1.3.1 Rubber Track Pads

2.1.3.2 Road Wheels

2.1.3.3 Track Tensioners

2.1.4 Track Loadings

2.1.4.1 Centrifugal Tension

2.1.4.2 Final‐Drive Torque Measurements

2.1.4.3 Lateral Horn Load

2.1.5 Rolling Resistance: Analytical Methods

2.1.5.1 On a Metal Wheel Path

2.1.5.2 On a Rubber Wheel Path

2.1.6 Rolling Resistance: Experimental Measurements

2.1.6.1 Chieftain

2.1.6.2 FV 432

2.1.6.3 Scorpion and Spartan

2.1.6.4 Summary

2.1.7 Noise and Vibration

2.1.8 Approaches for Reducing Noise and Vibration

2.1.8.1 Finite Element Analysis and Experimental Sprockets

2.1.8.2 Fully Decoupled Running Gear

2.1.8.3 Flexible Rubber Tracks

2.1.9 Reducing Noise and Vibration.

2.1.9.1 Stage (a): Establishing the Principal Noise Sources

2.1.9.2 Stage (b): Design and Production of the Resilient Mountings

2.1.9.3 Stage (c): Test Results with the Resilient Mountings

2.2 Flexible Tracks

2.2.1 Earlier Flexible Tracks

2.2.2 Contemporary Flexible Tracks

2.2.3 'Proof‐of‐Principle' Flexible Tracks for a Spartan APC

2.2.3.1 Mark 1 Tracks

2.2.3.2 Mark 2 Tracks

2.2.3.3 Mark 3 Tracks

2.2.3.4 Durability Trials

2.2.4 Later Developments

Chapter 3 Tracked Vehicle Suspension Performance: Modelling and Testing

3.1 Human Response to Whole‐Body Vibration (WBV) and Shock

3.1.1 BS 6841:1987 and ISO 2631‐1 (1997)

3.1.2 Further Standards Relating to WBV

3.1.2.1 Absorbed Power

3.1.2.2 The European Physical Agents (Vibration) Directive 2002/44/EC

3.1.2.3 ISO 2631‐5 (2004)

3.2 Terrain Profiles

3.2.1 Characterisation

3.2.2 DERA Suspension Performance Test Courses

3.2.3 Response of Multi‐Wheel Vehicles

3.2.4 Quarter‐Car Model

3.2.5 Computer Modelling

3.2.5.1 Parameter Specification

3.2.5.2 Assumptions

3.5.2.3 Examples of Use of the Model

3.5.2.4 Comparison with Trials Data

3.5.2.5 Upgrading the Suspension Performance of the Scorpion Family of Vehicles

3.2.6 Ride Performance Trials of a Challenger Suspension Test Vehicle

3.2.7 Pitch Response to Braking and Accelerating

3.2.7.1 Compensating Idler

3.2.8 Sprung Idler Test Vehicle (SITV)

Chapter 4 Controllable Suspensions

4.1 Height and Attitude Control

4.1.1 Tracked Vehicles

4.1.2 Wheeled Vehicles

4.2 Actively Controlled Damping (Semi‐Active Suspensions)

4.2.1 Adaptive Damping

4.3 Active Suspension Systems

4.4 DERA Active Suspension Test Vehicles

4.4.1 Narrow‐Bandwidth Systems

4.4.1.1 Wheeled Vehicle

4.4.1.2 Tracked Vehicle.

4.4.1.3 Laboratory Test Rig

4.4.2 Broad‐Bandwidth System

4.5 Conclusions

Chapter 5 Wheeled Vehicle Drivelines and Suspensions

5.1 Unarmoured Vehicles

5.1.1 Leyland DAF DROPS 8×6 Logistic Load Carrier

5.1.2 MAN SX 8×8 High‐Mobility Load Carrier

5.1.3 Pinzgauer 4×4 and 6×6 Light Trucks

5.1.4 Range Rover

5.1.5 Alvis Stalwart

5.1.6 Caterpillar Mining/Dump Truck

5.1.7 Euclid (Later Hitachi) Mining/Dump Trucks

5.2 Armoured Vehicles

5.2.1 H‐Drive

5.2.2 I‐Drive

5.3 Interconnected Suspensions

5.3.1 Methods of Interconnection

Chapter 6 Wheeled Vehicle Suspension Performance

6.1 Quarter‐Car Model

6.2 Wheelbase Filter

6.3 DROPS Truck Ride Measurements

Reference

Chapter 7 Steering Performance of Tracked and Wheeled Vehicles

7.1 Tracked Vehicles

7.1.1 Skid Steering Mechanisms

7.1.2 Skid Steering Models

7.1.3 The Magic Formula

7.1.4 Deriving the Magic Formula Parameters for the Track

7.1.5 Steering Performance Model

7.1.6 Results from the Model

7.1.6.1 Driver Control Arrangements

7.1.6.2 Pivot Turn

7.1.6.3 Effect of Radius of Turn on Slewing Moment

7.1.6.4 Driving on a 15 m Radius Turn at Varying Speed to Show the Effects of Track Tension and a Suspension System

7.1.6.5 Driving on a 15 m Radius Turn at Varying Speeds with New and Worn Pads and on a Low‐Friction Surface

7.1.6.6 Driving at 15 m s-1 on Turns of Varying Radii

7.1.6.7 Effect of the Centre of Gravity (CG) Position

7.1.6.8 Model Validation

7.2 Comparing Skid and Ackermann Steered Wheeled Vehicles

7.2.1 Tyre Force-Slip Data

7.2.2 Choice of Tyre Model

7.2.2.1 The Skid Steered Vehicle: Vehicle Model

7.2.3 Results from the Model

7.2.3.1 Neutral Turn

7.2.3.2 Variation of Slewing Moment with Radius of Turn.

7.2.3.3 Cornering on 15 m and 30 m Radius Turns at Different Speeds

7.2.4 Ackermann Steered Vehicle Model

7.2.5 Model Results

7.2.5.1 Steering Performance

7.2.5.2 Power Requirements

7.2.5.3 Tyre Wear

7.2.6 Torque Vectoring

7.2.6.1 Individual Wheel Motor Control

7.2.6.2 Articulated Vehicles

Appendix A: Equations of Motion

Appendix B: Power Flow Equations

Chapter 8 Soft‐Soil Performance of Wheeled and Tracked Vehicles

8.1 Basic Requirements

8.1.1 Soil

8.1.2 Basic Definitions

8.1.3 Soil-Vehicle Models

8.2 Models for Soft Cohesive Soils

8.2.1 Vehicle Cone Index (VCI) Model

8.2.1.1 Mobility Index for Tracked Vehicles

8.2.1.2 Mobility Index for Wheeled Vehicles

8.2.2 WES Mobility Number Model

8.2.3 Mean Maximum Pressure (MMP)

8.2.4 Vehicle Limiting Cone Index (VLCI)

8.2.4.1 Tyres

8.2.4.2 Tracks

8.3 Models for Dry Frictional Soils

8.3.1 WES Mobility Number for Wheeled Vehicles

8.3.2 DERA Trials

8.3.3 Tracked Vehicles

8.4 Space Efficiency of Running Gear Systems for Armoured Vehicles

8.5 Tractive Force-Slip Relationship for Tyres in Soft Cohesive Soils

8.5.1 Describing Force-Slip Characteristics

8.5.1.1 Rectangular Hyperbolae

8.5.1.2 Exponentials

8.5.2 The Magic Formula

8.5.3 Development of the Modified Magic Formula

Chapter 9 Effect of Free, Locked and Limited‐Slip Differentials on Traction and Steering Performance

9.1 Types of Lockable and Limited‐Slip Differentials

9.1.1 Lockable Differentials

9.1.2 Using the Braking System

9.1.3 Velocity‐Dependent Limited‐Slip Differentials

9.1.4 Frictional Limited‐Slip Differentials

9.2 Relationships for Frictional Limited‐Slip Differentials

9.3 Traction Performance

9.3.1 Traction Model

9.3.2 Model Results

9.3.2.1 Effect of Weight Transfer Across an Axle.

9.3.2.2 Different Soil Strengths Under the Tyres

9.3.2.3 On a Split μ Surface

9.4 Steering Performance on a Road Surface

9.4.1 Steering Performance Model

9.4.2 Model Results

Chapter 10 Articulated Vehicles

10.1 Articulated Tracked Vehicles

10.1.1 Traction Forces with Skid and Articulated Steering

10.2 Articulated Wheeled Vehicles

10.2.1 Steering Behaviour with Ackermann, Skid and Articulated Steering

10.2.1.1 Hard Surfaces

10.2.1.2 Soft Soils

Chapter 11 Vehicle Rollover Behaviour

11.1 Basic Considerations

11.2 Methods to Reduce the Likelihood of Rollover

11.2.1 Warning Systems

11.2.2 Electronic Stability Programmes

11.2.3 Active Anti‐Roll Bars

11.2.4 Driver Training

11.3 Truck Rollover: A Case Study

11.3.1 Calculating the Rollover Angle

Notation

Abbreviations

Bibliography

Index

EULA.

Notes:

Includes bibliographical references and index.

Description based on print version record.

ISBN:

9781523123599

1523123591

9781119258810

1119258812

9781119258803

1119258804

9781119258827

1119258820

OCLC:

1028581833