Abstract
This report deals with vibro-acoustic analysis using three-dimensional FEM for automotive seat structures having porous materials and metal frames. There are two media (i.e. internal air and a resin block) in the porous materials for the seat. By carrying out numerical analysis related to the model test, the porous materials for the automotive seat have sound absorption effects for cavity resonance in a room. This effect is mainly due to viscosity of internal air in the porous materials. Further the porous materials also have damping effects for the structural resonance of the metal seat frame under impact excitation at the metal frame. This effect is mainly due to viscoelasticity of the resin block in the porous materials. Furthermore, under an acoustic excitation from a speaker, vibration amplitudes of the metal frame increase by attaching the porous materials to the metal frame. It is "an effect of a sail" of the resin block in the porous material, which increases vibration level of the seat metal frame by receiving sound pressure. This effect can be simulated using Biot model for the porous materials, which have coupling effects between elastic deformations of the resin block and acoustic waves in the internal air.
