344 Damped vibration responses for automotive sound proof structure, and effects of connection using three dimensional fast finite element analysis

Abstract

A numerical method is proposed to calculate damping properties for mixed structure including elastic body, viscoelastic body and porous body. Displacement vectors as common unknown variable are solved under coupled condition. Further, explicit expressions of modal loss factor for the mixed structures are derived using asymptotic method. Using this technique, eigenvalue analysis and frequency response analysis are performed for some automotive body panels with sound proof structure. Further a spacer installed between the steel panels in the structures, to analyze deterioration of vibration.