Identification And Optimization Of Vehicle Road Noise Source Based On Transfer Path Analysis

Noise Vibration and Harshness(NVH)performance is an important indicator in the process of vehicles positive development,which will directly affect consumer’s consumption intention.In this paper,transfer path analysis(TPA)is used to analyze the vibration noise of the vehicles from the road incentives,and the results are used for experimental test.In the course of research,combined the CAE(Computer Aided Engineering)simulation and the experiment test.First,excitation force of each transmission path is obtained is the experiment.Further,the larger contribution path is calculated and optimized by CAE.At the end,the experimental test is completed and the expected effect is achieved.This paper mainly studied the vibration noise caused by pavement excitation in the new SUV development process.The driving condition is 60Km/h,and the road condition is outdoor straight asphalt pavement.Vibration transmitted from suspension system to body,radiating noise to the car room.The main task of the study is to reduce the vehicle noise,which method is to find the larger impact path,and optimize these several paths,the ultimate effect is to reduce the vehicle noise by reduce the left and right bar bushing stiffness,completed the required task.Here the concrete research:(1)Imported the 3D geometry modal in Hyper-mesh,built the finite element modal of Trimmed Body(TB)and the cavity modal,calculated the free modes of the Body In White,the acoustic cavity and the Trimmed Body.(2)To certain the position of the installation point which suspension installed on the vehicle(the same as the experiment test).Calculated the sensitive,inputted the road force spectrum and simulated the interior noise,compared the simulate with the experimental value to verify the simulation accuracy,meanwhile,acquire the contribution of each transfer path.(3)Using the LMS Test.Lab equipment to measured the acceleration of the point and the sound pressure of the vehicle,calculated the excitation force of the suspension system and the vehicle installation point by inverse system method.Input the excitation force of each installation point into the simulation modal,calculate the contribution of each path to the vehicle response,found out the larger contribution path.The simulation results show that reduce stiffness of the left and right connecting rod can effectively reduce the noise inside the car.Then corresponding to the actual vehicle test to verify the simulation results are feasible,successfully reduce vehicle noise.