Sound transmission loss evaluation of the composite cabin panel based on the equivalent method and hybrid FE-BEM

Abstract

A rapid prediction technique of Sound Transmission Loss (STL) is proposed to investigate the acoustic characteristics of the aerospace vehicle composite panel based on the equivalent method and the hybrid Finite Element method - Boundary Element Method (FE-BEM). The composite panel is equivalent to a single anisotropic plate using the classical laminate theory, and then its STL within a wide frequency band is predicted by the FE-BEM method. To verify the applicability of the equivalent method, modal tests and numerical analyses of the panel are carried out. To verify the correctness of the predicted conclusions, FE-BEM results are compared with FE-SEA results and experimental results. Results show that I) the equivalent method is correct to simulate the natural characteristics of symmetrical laminates, which are consistent with the experimental results; II) it's effective for the panel’s STL prediction via introducing the equivalent structure into the FE-BEM STL prediction model, and III) the FE-BEM method is superior to the FE-SEA method. The proposed method has application in acoustic characteristics analysis and design