Sound insulation numerical calculation of an automobile magnesium alloy dash based on FE-SEA hybrid method

Abstract

In order to solve the structure-borne noise in middle frequency range,an advanced method named hybrid finite element-statistical energy analysis(FE-SEA) was introduced to calculate the sound insulation performance of automobile components.This method possesses the advantages of finite element method or boundary element method for low frequency range and statistical energy analysis for high frequency range.According to the FE-SEA theory,a hybrid model of the Chrysler Viper magnesium alloy dash was built to validate whether the hybrid method was feasible to calculate the sound transmission loss of automobile body panel in middle frequency range.Diffuse acoustic field(DAF) was applied to the incident side of hybrid model as the acoustic excitation and semi infinite field(SIF) was applied to the transmitted side as the sound power receptor.The result of numerical calculation agreed well with that of experiment,which validated the feasibility of the hybrid FE-SEA method in solving the mid-frequency acoustic problems of the dash panel.Finally,the application of regional sound package method shows the advantage and convenience to optimize the surface vibration around the frequency of sound transmission loss curve trough(100-500 Hz) in order to get a better sound insulation quality.