Research On Hybrid FE-SEA Method For Vehicle Interior Mid-frequency Noise

With the development of economy, the improvement of living standards, peopleimprove the requirements for passenger cars. The NVH(Noise Vibration Harshness)performance which has the biggest influence in the process of using got the attention of thevehicle manufacturers gradually. In the mature analysis method, FEA and SEA could notsave the noise problem in middle frequency accurately and effectively. The hybrid FE-SEAmethod appeared in this background.This paper has studied the hybrid FE-SEA method in automotive of modeling andanalysis. Summarized the theory of hybrid FE-SEA method systematically; introducedthe related concepts and definitions. Given the coupling model of FEA and SEA;summarized the main formula used in the calculation process; List the premise of the hybridFE-SEA method.Measure the vibration and interior sound pressure level response of the vehicle insemi-anechoic room. Got the Modal density and damping lose factor of subsystem byexperiment or calculation. Measure the acoustical absorption coefficient of noise controltreatment by standing wave tube testing.Build up the Finished Automobile hybrid FE-SEA model, and listed the process. Withthe three kinds of working condition: idling, uniform velocity at60km/h and100km/h,Model was validated. The error is less than3dB(A).Using the method of contrastive analysis, studied the influence of structural subsystems,acoustic cavities subsystems, structural damping loss factor and line junction coupling lossfactor to computational accuracy of hybrid FE-SEA model. Do the analysis of acousticcavities subsystems contribution and the noise transmission path. Changed the design ofnoise control treatment in the model, reduce the interior noise effectively.