Damping Specification of Automotive Structural Components via Modal Projection

In the automotive industry damping has become an important and highly effective design parameter for reducing low-frequency vibroacoustic noise in the vehicle compartment. It is a fairly straightforward procedure to compute vibroacoustic frequency responses of a damped car body for a given excitation and to compare the resulting response levels to a prescribed specification over a frequency range. However, when specification levels are exceeded at particular frequencies, the engineer must be able to localize the relevant structural components to be damped and subsequently define the appropriate damping at the component level in order to satisfy the specifications at the vehicle level. This problem of damping specification has been under study at PSA Peugeot Citroën over the past several years and has recently resulted in a new methodology and corresponding software tool which are presented in this article.