Research On Structure Noise Prediction And Noise Reduction Of Train Based On FE-SEA Hybrid Method

Since the first high-speed rail opened in 2003,high-speed rail construction has been developing rapidly in China.In recent years,the fast and comfortable high-speed rail in China have set up a new benchmark for high-speed railway business operation all over the world.Because of the characteristics of fast and comfort,high-speed rail is popular at home and abroad.In order to ensure these advantages,we must attach great importance to reducing train vibration and noise.In this paper,the integrates advantages of the Finite Element Method(FEM)and Statistical Energy Analysis(SEA)is combined and the Finite Element-Statistical Energy Analysis(FE-SEA)hybrid method is employed to establish the train body-acoustic coupling model based on the acoustic-solid coupling theory.The model is divided into FE and SEA subsystems,which avoids the large calculation of FEM in the high frequency range and the low accuracy of SEA in the low frequency range.This method also solves the contradiction between the computation efficiency and the computation accuracy.This paper mainly carried out the following research work:(1)Referring to a large number of related papers at home and abroad,the basic concepts and definitions of FE-SEA hybrid method are introduced and the response solving formulas of FE subsystem and SEA subsystem are simply summarized.(2)FE-SEA hybrid method is employed to establish the train body structure and interior acoustic cavity coupling model by VA one software.The kinds of subsystem is classified by the number of modes in the band.Through the mode number analysis of the train body structure,the 200 Hz is identified as the frequency cut point.The model less than 200 Hz is calculated by FEM.And the model in the frequency of 200Hz-500 Hz is calculated by FE-SEA hybrid method.At the same time,the parameters needed for model simulation,such as modal density,internal loss factor and coupling loss factor are calculated.(3)SIMPACK software is employed to establish the train-track coupling model to calculate the secondary suspension force,which is the excitation to be input to the train body-acoustic cavity coupling model.The speed level and the acceleration level of the train structure vibration are analyzed and the floor has the largest vibration.(4)The internal noise of train body is analyzed,secondary suspension force has more significant in the low frequency band on the noise inside the train.The contribution of the train structure to the acoustic cavity is analyzed and the floor vibration has the highest contribution to the acoustic cavity where the ears of passengers are.(5)Light glass wool,mineral wool and felt are employed to analyze the control effect of different absorption material on the interior noise.The effect of noise reduction on light glass wool with different thickness is analyzed.Lastly,the noise reduction effect of micro perforated panel as a sound absorbing material is studied.