Analysis And Optimization Of Low Frequency Noise Of An SUV Model Based On Transfer Path

With the continuous improvement of domestic automobile users’ demand for the performance of automobile products,the investment of vehicle comfort technology requirements in the process of research and development has gradually increased.The NVH(Noise,Vibration and Harshness)performance of automotive products is an important performance index in the forward development process.Chinese residents mainly use cars on urban roads,and the proportion of high-speed sections is less than20%.In urban road conditions,vehicles drive at a medium and low speed,and generally transmit the excitation from the road to the body through the wheel and suspension system at a speed of 60km/h.The in-car noise and vibration response caused by this process directly affects the comfort degree of drivers and occupants.Therefore,the analysis and optimization of low frequency pavement excitation noise is an important link in the process of automobile product development.Based on the multi-reference transfer path analysis method,this paper analyzes the response of in-vehicle noise caused by road surface excitation during driving under specific working conditions through the experimental test and finite element simulation analysis of an SUV real vehicle provided by the car company.Firstly,the most classic frequency domain transfer path analysis method is used to analyze the noise transfer path,and the contribution of different paths to the target response point is analyzed by the product of the working load and the transfer function,and the frequency response function is obtained by experimental method to obtain the path with a large contribution of the noise in the vehicle.Secondly,the finite element model of the interior body and sound cavity is established,and the load spectrum is loaded on the body to calculate and predict the response in the car,and the test results are compared.Then,by testing the decorative body and the acoustic cavity mode,and comparing the simulation analysis data of the decorative body,acoustic cavity mode and transfer function test,it is known that the simulation and the test are more consistent,and the accuracy of the simulation model is verified.Finally,the accuracy of the model is further verified by the origin dynamic stiffness and noise transfer function,and based on the acoustic-solid coupling model of the interior body,the working condition load of the body installation contacts is substituted into the model for interior noise simulation.The simulation results provide a reliable basis for the road noise optimization of this model.Optimization measures are taken in areas with strong acquisition noise transmission paths to reduce interior noise on this model.The results show that it is feasible to study the low-frequency noise in the vehicle based on multi-reference transfer path analysis.According to the conclusions obtained by finite element simulation,this paper finds out the road noise excitation points and proposes an effective method to reduce the noise in the car.By taking improvement measures and comparing them with simulation,the rationality and feasibility of the road noise optimization scheme are obtained,which provides a theoretical basis for the noise optimization and improvement of new car products.