Vibration Analysis vs. Vibration Control

Car manufacturing companies and their suppliers allocate significant human and financial resources to NVH-related R&D. While the most advanced instrumentation and analytical techniques are used for these activities, the incremental improvements of NVH are rather small due to extreme complexity of the vehicle systems, to accumulating manufacturing uncertainties, and to many contradictory constraints for design and modifications of the vehicle components and subsystems. NVH improvement by using conceptual approaches for vibration and noise control without in-depth study of mechanisms generating objectionable noise and vibration effects in a particular component or subsystem is often considered as an inferior approach and is used only in critical launch and warranty situations. Development of such vibration and/or noise control “patches” is often relegated to suppliers. The paper illustrates, using case stories, high effectiveness of robust vibration and noise control devices, especially by using system resources and by using TRIZ methodology. Very radical improvements of noise and vibration characteristics have been achieved without extensive analytical efforts and without significant hardware modifications. One section of the paper relates to radical reduction of steering column shake, another to reduction of pass-by noise, the third to vibration isolation, and the forth to enhancing tire damping.