Research On The Radiation Characteristics Of Wheel Rail Noise In High Speed Trains

With the rapid development of high-speed train technology,the running speed of trains continues to increase,and the vibration between the wheels and rails of trains becomes increasingly obvious.The radiation noise of wheel rail vibration is one of the main noise sources of high-speed trains.Therefore,studying and controlling wheel rail noise has become increasingly important.Firstly,based on the theory of wheel rail interaction,this article calculates the force between wheels and rails,establishes a finite element model of high-speed train wheel sets and rails,and uses the finite element/infinite element method to calculate the noise generated by wheel rail vibration under the vehicle,and conducts a systematic analysis of it.(1)Calculation of wheel rail force.Based on the theory of wheel rail interaction,the rail velocity impedance spectrum and wheel velocity impedance spectrum are calculated through programming.The track irregularity simulation method is used to obtain the wheel rail roughness spectrum based on Sato wheel rail irregularity density spectrum.Based on the rail speed impedance,wheel speed impedance,and wheel rail roughness spectrum,combined with the Hertz nonlinear elastic contact theory of wheel rail,a wheel rail force calculation program was developed to calculate and analyze the vertical force of the wheel rail.Analyzed the effects of wheel radius,spoke thickness,tread quality,and roughness coefficient on vertical wheel rail force,and compared the Sato spectrum with the roughness spectrum calculation results of the Academy of Railway Sciences.(2)The modal analysis of the wheel-set and rail,as well as the vibration of the wheels,were calculated and analyzed.Using the CRH380 BL high-speed train wheel and CHN60 kg steel rail as research objects,a finite element model of the wheel and track structure was established.The first 50 modes of the rail and wheel were calculated and analyzed using the finite element method,and the vibration modes of the wheel and rail were analyzed.Using wheel rail force as excitation,the wheel rail force is applied to the contact point of the wheel rail,and the vibration of the wheel and rail is calculated.The radial and axial displacement and acceleration of the wheel and rail at the excitation point are analyzed.(3)The characteristics of wheel rail noise were calculated and analyzed.The finite element model of the wheel set and rail was imported into the acoustic calculation software,and a finite element/infinite element model of the sound radiation of the wheel set and rail was established.The sound radiation characteristics of the wheel and rail were calculated,and the sound pressure level changes of the wheel set and rail at the monitoring points were analyzed.Analyze the impact of speed changes on sound pressure levels,analyze the contribution characteristics of wheel and rail noise to wheel/rail noise at 200km/h,and draw a conclusion that wheel noise is the main source of wheel/rail noise in the low-frequency and high-frequency ranges,while in the mid-frequency range,wheel/rail noise mainly comes from the rail.(4)Calculate and analyze the characteristics of wheel rail noise under the vehicle.We have established an acoustic calculation model for the wheel rail structure under the vehicle,considering the influence of the vehicle body.The model includes a high-speed train body,two sets of wheel sets,two tracks,and a track plate under the track.The finite element/infinite element method was used to calculate the sound pressure level around the vehicle body,analyze the radiation law of the sound pressure level,and compare and analyze the sound pressure levels at 200km/h,250km/h,and 300km/h,as well as the sound pressure levels at the monitoring points on the side of the vehicle body.The results showed that the sound pressure level increased with the increase of speed.At low frequencies,the sound pressure level at the monitoring points at 1.2m was less than 3.5m,and at high frequencies,the sound pressure level at the monitoring points at 1.2m was greater than 3.5m.