| Wheel-rail noise is the main noise source of high-speed trains,and it is also an important part of rail transit noise.Among them,wheel radiation noise is the most important.Reducing wheel radiation noise can effectively reduce wheel-rail noise,so it is more meaningful to study the vibration and noise reduction of rail wheels.In this paper,the force between wheel and rail is calculated,the wheel finite element model is established,and the radiation noise of the wheel is calculated by using of the finite element/infinite element method.The main research contents are as follows:(1)The forces of both wheel and rail are calculate by programming.On the basis of vibration mechanics,the vertical velocity impedance spectrum of rail and the radial velocity impedance spectrum of wheel are calculated by using MATLAB programming.Using Chen Guo-Zhai Wanming’s new simulation method of track irregularity,and basing on Sato’s wheel-rail joint irregularity density spectrum,a program is compiled to calculate the wheel-rail roughness spectrum.According to Hertz contact theory,the program of wheel-rail interaction force is compiled and the vertical interaction force spectrum between wheel and rail is calculated.(2)The wheel and wheel pair modal are calculated.The wheel of the passenger train S-shaped web 915D in China is taken as a study objective,the finite element model of the wheel is established.The modal frequencies and modes of both wheels and wheelsets are calculated by using of Patran and Nastran software.The results show that the vibration amplitude of the web plate and the rim is larger after 1000Hz,therefor the web plate and the rim become the main vibration region of the wheel in the high frequency range.(3)The radiation efficiency and radiation noise of the wheel are calculated.The radiation efficiency and the first 10th modal radiation efficiency of the wheel are calculated by using of boundary element method of the ESI-VAone software in the frequency range of 160-5000Hz.The radiated noise of wheels is calculated and its distribution rule is analyzed by using of the direct frequency response method,and the variation of sound power radiated by wheels with running speed is calculated and analyzed.(4)The noise radiated by wheelset is calculated and analyzed.The finite element model of the wheelset considering the axle and without the axle is established,and the finite element/infinite element model of the noise radiated by the wheelset is constructed.Based on the finite element/infinite element method,the noise radiated by the wheelset is calculated by using of Actran software.The total sound level and sound level spectrum of the monitoring points are achieved and analyzed,and the distribution rule of the noise radiated by the wheelset pair is analyzed.(5)The noise characteristics radiated by the wheelset under the train is calculated and analyzed.A finite element/infinite element model considering the influence of the car body on the radiated noise of wheelset is established,the model includes the high-speed train body,four wheel pairs.Using the finite element/infinite element method,the acoustic radiation characteristics of wheels considering the car body are calculated,and the variation rule of the sound level under the train and on the side of the train body is analyzed.The radiated sound power levels of the wheelsets at 200 km/h,250 km/h and 300 km/h are calculated.Through multi-scheme comparison analysis,it is verified that the noise radiated by different numbers of wheels at the same monitoring point conforms to the principle of sound source superposition. |
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