1、Brake NVH Testing and Measurements James K. Thompson Brake NVH: Testing and MeasurementsBrake NVH: Testing and Measurements Other SAE titles of interest: Brake Tec HNology Ha NdBook By Karlheinz Bill and Bert J. Breuer (Product Code R-3375) Brake desig N aNd safe Ty, THird ediTioN By Rudolf Limpert
2、(Product Code R-398) adVaNced Brake Tec HNology By Bert J. Breuer and Uwe Dausend (Product Code: R-352) disc Brake squeal By Frank Chen, Chin An Tan, and Ronald L. Quaglia (Product Code: R-353) For more information or to order a book, contact SAE International at 400 Commonwealth Drive, Warrendale,
3、PA 15096-0001, USA; phone 877-606-7323 (U.S. and Canada only) or 724-776-4970 (outside U.S. and Canada); fax 724-776- 0790; e-mail CustomerServicesae.org; website http:/books.sae.org. Brake NVH: Testing and Measurements James k. Thompson Copyright 2011 SAE International eISBN: 978-0-7680-5371-5400 C
4、ommonwealth Drive Warrendale, PA 15096-0001 USA E-mail: CustomerServicesae.org Phone: 877-606-7323 (inside USA and Canada)724-776-4970 (outside USA) Fax: 724-776-1615 Copyright 2011 SAE International. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, d
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6、0-3480-6 SAE Order No. R-399 Library of Congress Cataloging-in-Publication Data Thompson, James K., 1951Brake NVH : testing and measurements / James K. Thompson.p. cm.Includes index.ISBN 978-0-7680-3480-61. AutomobilesBrakesTesting. 2. AutomobilesBrakesNoise. I. Title. TL269.T48 2011629.246dc2220100
7、51176 Information contained in this work has been obtained by SAE International from sources believed to be reliable. However, neither SAE International nor its authors guarantee the accuracy or completeness of any information published herein and neither SAE International nor its authors shall be r
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9、equired, the assistance of an appropriate professional should be sought. To purchase bulk quantities, please contact: SAE Customer Service E-mail: CustomerServicesae.org Phone: 877-606-7323 (inside USA and Canada) 724-776-4970 (outside USA) Fax: 724-776-1615 Visit the SAE Bookstore at http:/store.sa
10、e.orgv To my wife Shirley, without whom this book and much else would not be possible.vii Contents List of Figures ix List of Tables xiii Preface . xv Acknowledgments xvii Chapter 1: Basic Noise and Vibration .11.1 Definition of Noise and Vibration .21.2 Basic Terminology .21.3 Single-Degree-of-Free
11、dom Model .61.4 Spectral Analysis 91.5 Acoustics .131.6 Acoustic Environments .191.7 Frequency Analysis 211.8 Types of Sound Signals 251.9 Summary 26 Chapter 2: Brake Noise Characteristics . 272.1 Introduction . 282.2 Why Is Brake NVH Important? . 282.3 What Is Brake NVH? 292.4 Brake Squeal 302.5 Mo
12、an and Groan 332.6 Judder .352.7 Summary .37 Chapter 3: Brake NVH Measurements . 393.1 Introduction . 403.2 Transducers 403.3 Data Acquisition and Analysis 433.4 Coherent Output Power 473.5 Summary .53Chapter 4: Laboratory Testing . 554.1 Introduction . 564.2 Requirements for Brake Noise Testing in
13、the Laboratory 564.3 Brake NVH Dynamometers .574.4 Electric Motor 604.5 Mechanical Inertia and Inertia Simulation614.6 Enclosures .634.7 NVH Dynamometer Special Considerations . 664.8 Brake Noise Measurement Standards .674.9 Examples of Brake Dynamometers .784.10 Summary .85 Chapter 5: On-Road Testi
14、ng 875.1 Introduction . 885.2 Goals for On-Road Brake NVH Testing 885.3 Vehicle Instrumentation 885.4 Vehicle Test Procedures 915.5 On-Road Measurement Systems 1035.6 Summary .108 Chapter 6: Pad Natural Frequency and Damping Testing 1096.1 Introduction 1106.2 Standardization Process 1106.3 Summary 1
15、20 Chapter 7: Future Trends 1217.1 Introduction . 1227.2 Environmental Conditions 1227.3 Low-Frequency Brake Noise Tests 1237.4 Representing Vehicle Effects 1247.5 Judder Measurement . 1247.6 Subjective Correlation 1257.7 New Equipment . 1267.8 Summary .127 References 129 Index 131 About the Author
16、.135ix List of Figures Chapter 1 1. Vehicle noise sources. 2. Simple mass and spring system (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).3. Relationship among acceleration, velocity, and displacement of vibration (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).4. Single-degree-o
17、f-freedom vibration model (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).5. The effect of mass changes on a one-degree-of-freedom system (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).6. One-degree-of-freedom system with damping (Courtesy Brel & Kjr Sound & Vibration Measurements
18、 A/S).7. Multi-degree-of-freedom system model (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).8. Real-world vibrating system (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).9. Potential sources of vibration (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 10. Different typ
19、es of sources of vibration (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 11. Sound as a vibration in air (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 12. Terminology of sound (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 13. Sound measurement parameters (Courtesy
20、 Brel & Kjr Sound & Vibration Measurements A/S). 14. Sound pressure versus sound power (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 15. The range of sound pressure amplitudes (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 16. Computing sound pressure levels (Courtesy Brel & K
21、jr Sound & Vibration Measurements A/S). 17. The A-weighting frequency correction. 18. Ideal sound fields (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 19. Moving from the time to the frequency domain (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).x 20. Example of a real-world f
22、requency spectrum (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 21. Example of a real-world time signal (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 22. A frequency spectrum analyzer (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 23. Common frequency analysis form
23、ats (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). 24. Types of sound signals (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). Chapter 21. The frequency range of common brake noises. 2. Example of typical brake rotor resonant frequencies. 3. An Example of a brake rotor bending mo
24、de shape. 4. Example of squeal during a test stop (Courtesy Link Engineering Company).5. Time waveform of a moan noise (Courtesy Link Engineering Company).6. Frequency spectrum of the example moan vibration (Courtesy Link Engineering Company). Chapter 31. Schematic of data Acquisition and analysis f
25、or brake NVH testing (Slide 4-16).2. Brel & Kjaer type 4189 microphone (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).3. Microphone directivity pattern (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).4. Brel & Kjaer type 4393 accelerometer (Courtesy Brel & Kjr Sound & Vibration Me
26、asurements A/S).5. The Brel & Kjaer data acquisition and analysis system (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).6. Demonstration of the effects of averaging. 7. Example of a brake squeal spectrum (Courtesy Link Engineering Co.).8. Typical city traffic summary report (Courtesy Link
27、Engineering Co.).9. Typical example of frequency data for brake NVH measurements. 10. Brake torque order plot. 11. Basic system diagram. 12. Coherence to example case (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).xi 13. Coherent power for example case (Courtesy Brel & Kjr Sound & Vibratio
28、n Measurements A/S). 14. Comparison between sound pressure level spectrum and coherent output power for example case (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). Chapter 41. Brake NVH dynamometer drawing (Courtesy Link Engineering Co.).2. Brake NVH dynamometer photo layout (Courtesy Lin
29、k Engineering Co.).3. Chassis dynamometer drawing (Courtesy Link Engineering Co.).4. Chassis dynamometer designed for Brake NVH testing (Slide 4-8).5. Example of the performance capabilities of a dynamometer using inertia simulation (Courtesy Link Engineering Co.).6. Typical brake NVH dynamometer en
30、closure (Courtesy Link Engineering Co.).7. Example test enclosure background noise levels. 8. SAE J2521 Pressure Apply Ramp Specification. 9. SAE J2521 Microphone Placement Specification. 10. Examples of different types of test fixtures (Courtesy Link Engineering Co.). 11. First page of Standard SAE
31、 J2521 report (Courtesy Link Engineering Co.). 12. Second page of Standard SAE J2521 report (Courtesy Link Engineering Co.). 13. Cumulative noise occurrence plot from SAE J2521 test (Courtesy Link Engineering Co.). 14. Example of SAE J2521 test results: Noise after fade section (Courtesy Link Engine
32、ering Co.). 15. Example of SAE J2521 test results: High noise occurrences (Courtesy Link Engineering Co.). 16. Example of SAE J2521 test results: Strong noise suppressed after fade (Courtesy Link Engineering Co.). 17. Example of SAE J2521 test resultsVery noisy brake (Courtesy Link Engineering Co.).
33、 18. Link model 3900 and 4900 brake dynamometers (Courtesy Link Engineering Co.). 19. Variations in test enclosures (Courtesy Link Engineering Co.). 20. Link model 4900 two-roll chassis dynamometer (Courtesy Link Engineering Co.). 21. Link four-roll chassis dynamometer (Courtesy Link Engineering Co.
34、). 22. Drawing of four-roll chassis dynamometer installation (Courtesy Link Engineering Co.).xii Chapter 51. Head and torso simulator for binaural sound measurements.2. Two on-road brake NVH measurement systems (Courtesy Link Engineering Co.).3. Instrumented vehicle (Courtesy Link Engineering Co.).4
35、. SAE J2625 Example Results Report (Courtesy Link Engineering Co.).5. Los Angeles City Traffic Route (Courtesy Link Engineering Co.).6. Los Angeles City Traffic Route instrumentation (Courtesy Link Engineering Co.)7. Typical LACT Daily Summary Report page 1 (Courtesy Link Engineering Co.).8. Typical
36、 LACT Daily Summary Report page 2 (Courtesy Link Engineering Co.).9. Typical LACT Daily Summary Report page 3 (Courtesy Link Engineering Co.). 10. Problem squeal testing vehicle corner instrumentation (Courtesy Link Engineering Co.). 11. Problem squeal test results (Courtesy Link Engineering Co.). 1
37、2. Link model 3801 data acquisition system (Courtesy Link Engineering Co.). 13. Link model 3501 data acquisition and analysis system (Courtesy Link Engineering Co.). 14. Link model 3501 configuration (Courtesy Link Engineering Co.). 15. Brel & Kjaer NVH data acquisition and analysis module (Courtesy
38、 Brel & Kjr Sound & Vibration Measurements A/S). Chapter 61. First round robin natural frequency results for a single brake pad. 2. First round robin damping results for a single brake pad. 3. Basic measurement arrangement for pad damping and natural frequency test. 4. Instrumentation configuration
39、for pad test.5. Excerpt from SAE J2598 description of excitation and response measurement locations. 6. Effect of foam on damping measurement. 7. Analyzer display for proper SAE J2598 measurement. 8. Improvement in natural frequency measurement with SAE J2598. 9. Improvement in damping measurement w
40、ith SAE J2598.xiii List of Tables Chapter 11. Units of vibration amplitude (Courtesy Brel & Kjr Sound & Vibration Measurements A/S).2. Human perception of sound (Courtesy Brel & Kjr Sound & Vibration Measurements A/S). Chapter 2 None Chapter 3 None Chapter 41. SAE J2521 Test Matrix summary. 2. Class
41、ification of brake NVH test fixtures (Courtesy Link Engineering Co.). Chapter 51. Summary of SAE J2625 Test Matrix. Chapter 61. SAE J2598 Gage R&R results with manual hammer. 2. SAE J2598 Gage R&R results with automated hammer. xv Preface This book is intended to serve as an introduction to brake no
42、ise and vibration testing and measurement for those new to the field. It should be useful to both those familiar with vibration and acoustics and those who are just entering the field. Those familiar with noise and vibration may want to skip or quickly scan the first chapter to go directly into the
43、discussion of brake-related noise and vibration issues. Despite many decades of work on the measurement of brake noise and vibration, the field has only become mature in the last eight to 10 years. During this period, standard test procedures have been established and some of the key issues to gener
44、ating consistent results have been documented. This text summarizes the recent standards and practices that have led to successful measurements among investigators worldwide. In Chapter 1, a brief review of noise and vibration is provided for those not familiar with the field. While this discussion
45、is not a comprehensive course in noise and vibration, it does review the basic concepts and much of the terminology to be used throughout the text. Where possible concepts discussed are related to brake noise and vibration issues to make the material as relevant as possible. A summary of common brak
46、e noise and vibration issues is provided in Chapter 2. The broad scope of brake noise issues is defined in terms of the frequency range and conditions leading to various kinds of brake noise. Several specific common brake noise and vibration issues are defined in detail. These detailed descriptions
47、also serve to highlight the approach to be used throughout the text in defining measurements and the critical issues in consistent and reliable brake noise and vibration tests. The instrumentation, transducers, and other technical details of brake measurement are described in Chapter 3. The critical
48、 considerations in selecting, configuring, and validating measurement systems and transducers are described in this section. In addition, background material is provide to explain why some of the common transducer types and analyzer settings are not appropriate for brake noise and vibration measurem
49、ents. Chapters 4 and 5 describe measurement practice in detail for laboratory and on- road measurements, respectively. In each chapter, measurement standards and examples of measurement results are used to illustrate best practices. Example results are used to highlight the common characteristics and how to analyze the results obtained. These chapters also contain extensive discussions of the available and commonly used test equipment and measurement systems to xvi Brake NVH: Testing and Measurements illustra
