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Non-contacting test methodology studies of automotive body components have become a very useful, high resolution and sensitive test technique to engineering personnel. Continuous wave laser holometry, computer aided holometry (CAH), pulsed laser holometry and a scanning laser system were used to image vibration patterns. These methods were selected because of improved data turn-around time in the test development process while having no mass-loading effects on the sheet metal panels. An analysis of the vehicle body structure was conducted to improve the interior body structure sound quality and to reduce road noise presence. An interrogation of the interior noise spectrum identified critical frequencies affecting vehicle NVH. This paper addresses the results of using the aforementioned non-contacting test methods to reduce panel responses by developing an optimum rib section and pattern, and the addition of adhered stiffening materials.

Work has been performed to study side glass vibrations of a typical automobile using a scanning laser vibrometer. The objective of this work was to achieve better understanding of the source and path mechanisms for aeroacoustically generated wind noise. As a tool for measuring aeroacoustically generated vibrations, the laser vibrometer presents many advantages over traditional methods. These advantages, discussed in this paper, include rapid setup, full field imaging, high spacial resolution, non-contact operation, and wide dynamic and frequency ranges.