Structural-Acoustic Coupling Analysis of the Vehicle Passenger Compartment with the Roof, Air-Gap, and Trim Boundary

A theoretical model is made to investigate the coupling effects of the trim and air gap on the frequency response characteristics of a passenger compartment. With the model, a parametric study is carried out to understand the relation between the acoustic response of the cavity and the design variables associated with the roof, trim, and air gap between the two. The validity of theoretical formulations is verified through a comparison between the theoretical results and the finite element analysis results. Finally, an experiment for a simplified compartment cavity model is performed to confirm the theoretical results. This study reveals that the resonance peak level of an acoustic mode, which has a nodal surface parallel to the trim, can be significantly reduced by properly designing the trim mass and the gap thickness of the trim-air gap system. [S0739-3717(00)00303-2]