Reducing noise levels in vehicles by padding rubber layers at structural interfaces

This paper deals with the noise reduction of coupled fluid-structure system in a low frequency band. Passive rubber layer is introduced to junction between substructures to reduce noise in the cavity. The noise level and the vibration in the system can be modified by changing rubber layer configurations. A hybrid modal synthesis is proposed to investigate the forced responses of fluid-structure system, which allows studying the system behavior with few degrees of freedom. An optimization procedure following an interpolation process is provided in the interest of reducing noise level in the cavity. The optimal design configuration is then analyzed from a modal overview. The efficiency of this noise reduction strategy is demonstrated by a numerical example.