Research On Simulation Prediction Of Interior Noise Of Pantograph Train On 400km/h High-speed Train

With the increasing of the running speed of high-speed train and the requirement of people for comfort,the noise control in the vehicle becomes more and more important.If the vehicle noise prediction is carried out before the production by simulation method,and the noise control scheme is proposed for the parts with high noise,which can reduce the manufacturing cost of the train and shorten the design period.This paper takes a high-speed train pantograph as the research object,establishes the noise prediction simulation model of the pantograph,and forecasts the noise within the vehicle with an hourly speed of 400 km by using statistical energy analysis method.According to the prediction results,the noise reduction scheme is put forward to meet the acoustic requirements of the pantograph when it is running at 400 km / h.In this paper,the equivalent method based on dynamic and modal characteristics is used to establish the hollow profile equivalent plate.The acoustic characteristics before and after the equivalent remain unchanged,so as to improve the prediction accuracy of vehicle interior noise.For the beam structure under the train,this paper calculates the section parameters of the beam structure,and gives the beam section parameters to build the statistical energy analysis beam structure in VA One.In order to obtain the excitation data of 400 km / h,the excitation data of 400 km / h is obtained by fitting and extrapolating the excitation data of similar pantograph trailers at different speed levels.According to the drawings provided by the manufacturer,the pantograph train simulation prediction model is established,and 350 km / h excitation data is applied to predict the noise.The accuracy of the model is verified by comparing the simulation value with the measured data.Then the 400 km / h excitation data is imported to predict the interior noise of the 400 km / h pantograph.According to the power flow analysis,the main sources of interior noise are obtained,and the feasible noise control scheme is put forward.Statistical energy analysis is the most effective method to solve the problem of acoustic vibration analysis,but there are still some shortcomings in the practical engineering application.In view of the problem that the statistical energy analysis theory divides a subsystem with similar mode into several subsystems in engineering application,which leads to the insufficient mode density of subsystems and the decrease of accuracy of calculation results,this paper proposes a statistical energy analysis method based on virtual partition,and derives the calculation method of the virtual partition theory,The sound pressure method is used to measure the incident sound power of the aluminum plate,the sound pressure level of the virtual division cavity is measured by the sound sensor,the internal loss factor of the aluminum plate is measured by the free attenuation method,and the internal loss factor of the cavity is obtained by the reverberation chamber method.The coupling loss factor between subsystems is obtained by simulation and theoretical calculation,This time,the formula is used to calculate directly.Through the programming calculation of the statistical energy analysis method based on virtual partition,the accuracy of the virtual partition theory is verified by comparing the simulation results of VA One software with the experimental measurement results.The first mock exam is to solve the problem of the modal density of subsystems caused by subsystem partition when the statistical analysis is carried out in large structures.The analysis of the large structure’s acoustic vibration can also be effectively analyzed at low frequencies,so that the acoustic analysis of high,medium and low frequencies can truly be unified into an acoustic model.