Vehicle Noise, Vibration, and Sound Quality By Gang Sheng (Gang Sheng Chen) SASInternational Warrendale, Pennsylvania USA
Table of Contents Preface ix Chapter 1 Introduction to Vehicle Vibrations and Sound 1 11 Vehicle vibrations and sound 2 111 Vehicle systems, subsystems, and components 2 112 Sources, paths, and receivers of vibrations and sound 3 12 Characteristics of vehicle vibrations and sound 3 13 Significance of vehicle vibrations and sound 7 Chapter 2 Fundamentals of Vehicle Vibrations and Sound 11 21 Introduction 12 22 Fundamentals of vibration 12 221 Vibration of linear discrete and continuous systems 12 222 Random vibrations 34 23 Fundamentals of sound 49 231 Airborne sound and measures 50 232 Sound perception and weighting curves 51 233 Sound wave equation 55 234 Sound radiation of structures 58 235 Acoustic wave transmission, adsorption, and reflection 59 24 Analysis and testing approaches 62 241 Finite element and boundary element methods 62 242 Modal analysis and modal synthesis methods 73 243 Transfer path analysis 83 244 Statistical energy analysis 98 245 Testing techniques 777 V
25 Control of vehicle vibrations and sound 126 251 Basic features of vehicle vibrations and noise 126 131 252 Mode mapping and frequency separation of subsystems/components 130 253 Vibration reduction using isolator and absorber 254 Damping treatment 133 255 Noise control through insulation 133 256 Noise control through absorption material or structure 134 257 Active and semi-active control of noise and vibrations 136 258 Fundamentals of sound quality 150 Chapter 3 Powertrain Vibrations and Sound 169 31 Introduction 170 32 Engine vibrations 170 321 Engine vibration sources 171 322 Torsional vibrations 178 323 Bending vibrations of engine crankshaft 203 33 Engine noise 204 337 Introduction 204 332 Engine noise sources 206 333 Combustion noise 209 334 Engine mechanical noise 218 34 Transmission vibrations and noise 238 341 Transmission whine 238 342 Transmission rattle 241 343 Clutch system vibrations and noise 243 35 Sound in air intake and exhaust systems 247 351 Noise in air intake system 247 352 Sound in air exhaust systems 268 36 Drivetrain vibrations and noise 292 361 Driveline system and vibration and noise 292 362 Run-out, second-order excitation, unbalance, and critical speed of shaft 294 363 Vibrations and noise in driveline systems 300 37 Powertrain system vibration isolation 302 377 Vibration isolation 302 vi
372 Isolation evaluation using six-degree-of-freedom model 304 373 Engine mounts 312 374 Optimization of powertrain vibration isolation 316 Chapter 4 Vibrations and Sounds of Body and Chassis Systems 327 41 Introduction 328 42 Vehicle interior noise: structure-borne noise 329 421 Vehicle body structural vibration mode and sensitivity, acoustic modes of vehicle compartment 329 422 Structural vibration, noise, and damping treatment 337 423 Excitation transmissions of body structure connection points 343 424 Sources of structure-borne interior noise 347 43 Vehicle interior noise: airborne noise 355 431 Sources of airborne noise 355 432 Powertrain airborne noise 356 433 Road and tire noise mechanisms 357 434 Sound treatment of vehicle 362 44 Wind noise 375 441 Introduction 375 442 Wind noise mechanism and testing 376 443 The analysis of wind noise 381 444 Wind noise abatement 385 45 Squeak and rattle 387 451 Friction- and impact-induced vibrations and noise 388 452 Squeak and rattle control 390 46 Brake system vibration and noise 393 461 Introduction 393 462 Low-frequency vibration and noise 399 463 Low-frequency squeal 402 464 High-frequency squeal 403 47 Vehicle low-frequency vibrations 405 471 Introduction 405 vii
472 Whole vehicle vibrations at low frequency and ride dynamics 406 473 Vehicle structure vibrations of low frequency 424 474 Seat vibrations 432 475 Steering wheel system vibrations 435 Chapter 5 Evaluation of Vehicle Vibrations and Sound 447 51 Introduction 448 52 Noise and sound quality evaluation 448 521 Pass-by noise: Regulatory requirement 448 522 Interior noise: customer requirement 454 523 Sound quality: customer perception 461 53 Vibration evaluation 469 531 Body characteristics under vibration environment 469 532 Discomfort and subjective evaluation 469 533 Objective evaluation of ride discomfort 472 534 Linear human body modeling 474 535 Objective evaluation of seats 476 536 Vehicle vibration evaluation 479 Index 485 About the Author 493 viii