1st Edition

Analyzing Friction in the Design of Rubber Products and Their Paired Surfaces

By Robert Horigan Smith Copyright 2008
    424 Pages 191 B/W Illustrations
    by CRC Press

    Taking a mechanistic approach that emphasizes the physical behavior of rubber as it slides, Analyzing Friction in the Design of Rubber Products and Their Paired Surfaces integrates the engineering and scientific evidence demonstrating that the laws of metallic friction do not apply to rubber. The book also presents a newly developed, scientifically based unified theory of rubber friction that incorporates a fourth basic rubber friction force: surface deformation hysteresis.

    With applications that phenomenologically treat both static and dynamic rubber friction, the book offers practical guidance for implementing the unified theory in the analysis and design processes. The use of this theory enables comprehensive calculations of rubber friction, thereby offering opportunities to enhance public safety. While the theory applies to all elastomeric products where friction is an issue, the author primarily focuses on:

    •          Analyzing friction in the design of rubber tires and their contacted pavements

    •          The geometric design of roadways

    •          Motor vehicle accident reconstruction

    •          Analyzing slip resistance in the design of footwear and their contacted walking surfaces

    Supported by extensive analytical evidence, this book details what rubber friction is and why it behaves the way it does.

    Preface
    Introduction
    Historical Background
    Purposes of the Book
    The Unified Theory of Rubber Friction
    Surface Deformation Hysteresis in Rubber
    Differences between Metallic and Rubber Friction Mechanisms
    Consequences Stemming from Use of the Traditional Metallic Friction Approach to Rubber Friction Analysis
    Approach to the Subject
    Organization of the Book
    Metallic Coefficient of Friction
    Introduction
    Smooth Metal Friction
    Adhesion Theory of Smooth Metal Friction
    Origin of the Friction Force between Smooth Metals
    Rough Metal Friction
    Laws of Metallic Friction
    Rubber Friction Mechanisms
    Introduction
    Rubber Friction Coefficient Decreases with Increasing Load
    Adhesion as a Rubber Friction Mechanism
    Linking Rubber Friction to the Real Area of Contact
    Hertz Equation
    Bulk Deformation Hysteresis in Rubber
    Concurrently Acting Rubber Friction Mechanisms
    Van der Waals’ Adhesion and Surface Deformation Hysteresis in Rubber
    Adhesion, Bulk Deformation Hysteresis, and Wear in Sliding Rubber
    Expressions for Bulk Deformation Hysteresis in Rubber
    Modified Hertz Equation
    Schallamach Waves
    Elastomeric Friction
    Microhysteretic Contributions to Wet Rubber Friction
    Metallic Coefficient-of-Friction Equation Does Not Apply to Rubber
    Introduction
    Coefficient of Rubber Friction on Dry, Smooth Surfaces
    Coefficient of Rubber Friction on Dry, Textured Surfaces
    Coefficient of Rubber Friction on Wet, Smooth Surfaces
    Coefficient of Rubber Friction on Wet, Textured Surfaces
    Constant (Metallic) Coefficient-of-Friction Equation Not Applicable to Rubber
    A Unified Theory of Rubber Friction
    Introduction
    Rubber Microhysteresis Development on Macroscopically Smooth Surfaces
    Rubber Microhysteresis Development on Macroscopically Rough Surfaces
    Characteristics of the Rubber Microhysteresis Mechanism
    No-Load Adhesion Hypothesis
    Rubber Surface Deformation Hysteresis Testing
    A Unified Theory of Rubber Friction
    The Rubber Adhesion-Transition Phenomenon
    Introduction
    Further Aspects of the Rubber Adhesive Friction Mechanism
    Adhesive Friction of Metal and Nonelastomeric Plastics in the Elastic Loading Range
    Determinants Controlling the Value of PNt
    Controlling Adhesion-Transition Pressure to Optimize Friction Development
    “Low” μA Values in the Low Loading Range
    Microhysteretic Friction in Dry Rubber Products
    Introduction
    Microhysteresis in Automotive Tire Rubber in Dry Conditions
    Microhysteresis in Dry Aircraft Tires
    Rubber Microhysteresis in Dry Footwear Materials
    Microhysteresis in Dry Rubber Belting
    Rubber Adhesion-Transition Pressure Phenomenon on Macroscopically Rough Surfaces
    Microhysteresis in Wet Rubber Products
    Introduction
    Effects of Wet Lubricants on the Rubber Adhesion Mechanism
    Microhysteresis in Automotive Tire Rubber under Wet Conditions
    Microhysteresis in Wet Aircraft Tires
    Rubber Microhysteresis in Wet Footwear Outsoles
    Ramifications of the Presence of Microhysteresis in Wet Rubber Products
    Rubber Adhesion-Transition Phenomenon on Wet Surfaces
    Rubber Microhysteresis in Static Friction Testing
    Introduction
    Does Static Friction in Rubber Exist?
    Two Portable Static Friction Testing Devices
    Definition of Static Friction
    Rubber Microhysteresis in Static Friction Testing
    Independence of the Rubber Microhysteresis Force in Static Friction Testing
    Adhesion and Rubber Microhysteresis in VIT Testing
    Bias in Portable Walking-Surface Slip-Resistance Testers
    Introduction
    Remediable Inertial Bias in Portable Walking-Surface Slip-Resistance Testers
    Irremediable Inertial Bias in Portable Walking-Surface Slip-Resistance Testers
    Remediable Residence-Time Bias in Static Friction Testing
    Irremediable Adhesion-Transition Bias in Portable Walking-Surface Slip-Resistance Testers
    Contact-Time Bias for Tribometer Comparability
    Nonscientific Application of the Laws of Metallic Friction to Rubber Tires Operated on Pavements
    Introduction
    Comparing the Characteristics of Rubber Friction to Metallic Friction
    Effects of the Development of Microhysteretic Forces on Tire Friction Analysis
    Comparability of Rubber Friction Testing Data
    Inadvertent Misapplication of the Laws of Metallic Friction to Rubber Tires in ASTM Test Standards
    Inadvertent Misapplication of the Laws of Metallic Friction to Rubber Tires in Motor Vehicle Accident Reconstruction
    Inadvertent Misapplication of the Laws of Metallic Friction to Rubber Tires in the Geometric Design of Roadways
    Friction Analysis in the Design of Rubber Tires and Their Contacted Pavements
    Introduction
    Importance of Tire Microhysteresis on Wet Pavements
    Reformulation of the Traditional Friction Force vs. Tire Slip Relationship
    Measuring Tire Microhysteresis on Wet Pavements in the Design Process
    Application of the Unified Theory to Analysis of Friction in the Design of Tire-Pavement Systems
    Nonscientific Application of the Laws of Metallic Friction to Footwear Outsole Walking-Surface Pairings
    Introduction
    Comparing the Characteristics of Rubber Friction to Metallic Friction
    Effects of the Development of Microhysteretic Slip-Resistance Forces on Rubber Friction Analysis
    Comparability of Slip-Resistance Testing Data
    Inadvertent Misapplication of the Laws of Metallic Friction in ASTM Slip-Resistance Testing Methods
    Inadvertent Misapplication of the Laws of Metallic Friction by Slip-Resistance Testing Devices That Are Not the Subject of Active ASTM Standards
    Irremediable Inertial and Residence-Time Bias in Slip-Resistance Testing Devices That Are Not the Subject of ASTM Standards
    Slip-Resistance Analysis in the Design of Footwear Outsoles and Their Paired Walking Surfaces
    Introduction
    Importance of Footwear Outsole Microhysteresis in Wet Conditions
    Reformulating the Traditional Approach to Walking-Surface Slip-Resistance Testing
    Measuring Footwear Outsole Microhysteresis on Wet Walking Surfaces in the Design Process
    Application of the Unified Theory to Analysis of Slip-Resistance in the Design of Footwear Outsole Walking-Surface Pairings
    Index
    A Chapter Review and References appear at the end of each chapter.

    Biography

    Robert Horigan Smith