Interior Noise Simulation and Low-frequency Noise Reduction of a Vehicle's Cab

A body-in-white (BIW) finite element model of a vehicle's cab was established and its structural modals were computed and analyzed. The finite element model was modified through the comparison of the result with the test result with their deviation of the first eight order natural frequencies between them controlled within 3%. Then, the sound- structure coupled finite element model was built. The sound pressures inside the cab excited by structural vibration under two test conditions were calculated. It was found that the calculation results and test results were in good agreement. Therefore, the correctness and effectiveness of the model and the method were verified. Finally, the contribution of the wall panels of the cab to the sound pressure in the low-frequency range was analyzed. And the free damping layer was applied to the panels to reduce the noise in the cab. Results of computation show that the noise was effectively reduced.