Microstructure evaluation of urethane impregnated fibre Materials

Abstract

With the spread of electric and hybrid vehicles, noise from internal combustion engines has decreased and low-frequency noises such as road noise and wind noise have become relatively more prominent.In order to suppress this problem, attention is being paid to laminated structures in which foam and fibre materials, which are porous materials, are moulded into one piece.Sound-absorbing materials with an integrally moulded laminated structure have a mixed layer of foam impregnated with fibre material.In this study, the acoustic properties of integrally moulded laminated structures with mixed layers measure.The model is examined from the microstructure of the mixed layer by a homogenisation method based on the asymptotic expansion method.