Verification of Modal Density Descriptions of Analytical SEA Parameters for Structure-Borne Sound by Using FEM

Abstract

This paper verifies the expressions for power input and subsystem energy by modal density of subsystem in Statistical Energy Analysis (SEA) by means of FEM calculation. First, vibration response in the modal form is used to derive their expressions. It is shown that the employment of average in space and frequency for the power input and subsystem energy of the subsystem can be expressed mainly by the modal density. Coupling loss factor between plate subsystems is also analytically estimated by using the wave theory and is determined mainly by the modal density. In order to verify their modal density descriptions, FEM calculations are performed to compare subsystem energies, power inputs and coupling loss factors on three kinds of structures with different subsystem shapes with the same modal densities. The analytical SEA predictions are also compared with the FEM calculation results.