The finite element model of FT80 tractor’s cab is established by using FEM software ANSYS. Then, using the acoustics software SYSNOISE, the soundsolid coupling analysis with the combination of FEM and intermediate BEM is carried out. By means of the intermediate BEM, the acoustic characteristics of the cab are computed and analyzed. The sound pressures of neartheear sound fields of three cases—empty cab, cab with a chair in it, and cab with a chair and a driver in it—are computed and compared. The acoustic contribution of the chair and the driver in the cab is calculated and analyzed. It is proved that the chair and the driver have some influences on the internal noise of the cab. These influences should be considered in the modeling.

Because of the difficulty to actuate the large structures in low frequency region, the mechanical impedance data of the large structures at low frequency has small coherence factor and low reliability. In this paper, a finite element code is used to establish an FE model for large cabin structure, and the mechanical impedance of a submarine cabin base in the low frequency region is calculated. The numerical results are compared with those of experimental measurement and theoretical assessment. The feasibility for forecasting the mechanical impedance characteristics of the base in the low frequency region by means of the finite element method is evaluated. The disadvantage of the low reliability of the measured mechanical impedance data of the cabin base at the low frequency is improved. This method is valuable for engineering application.