Prediction On The Vibration And Sound Radiation Characteristics Of The Train Wheel & Development Of Noise And Vibration Control Devices For The Train Wheel

In order to reduce railway rolling noise of the high-speed and metro wheels, a wheel-rail rolling noise model is set up, based on the hybrid FEM-BEM method and wheel-rail noise mechanism. This model is used to calculate the vibration and sound characteristics and develop wheel noise control devices.First, three types of high-speed wheels and four types of metro wheels currently in operation in China are investigated, and their three dimensional FEM models and acoustic BEM models are developed. Based on the method mentioned above, the sound radiation characteristics of different types of wheel excited by typical wheel-rail combined roughness in the nominal contact point are investigated.Then, a new type of metro wheel in China is investigated. In the analysis procedure, a three-dimensional finite element model for the wheel is developed and the free vibration and frequency responses under different excitations are calculated. In the dynamic response calculation, three types of exciting forces are considered:normal unit force at the nominal rolling circle, horizontal unit force at the wheel flange and a vertical equivalent irregularity force depending on the average roughness of the wheel and rail at the nominal rolling circle. Then the velocity boundary conditions for the acoustic model are formed by using the vibrations of the structure, and the sound radiation characteristics are calculated based on the acoustic boundary element method. The effect of web-mounted braking disc on the sound radiation characteristics of the wheel is fully investigated.In the final, a new type of web-mounted noise shielded and vibration damped device used for wheel rolling noise control is developed. This device consists of multiple constrained damping plates which are alternatively anchored to the wheel rim and the wheel hub. Based on the method mentioned above, The CRH3 high-speed wheel are used to set up the vibration and sound radiation model of the wheel with the web-mounted damping screen. Through numerical methods, the effects of different types of damping materials and the temperature-frequency variance characteristics of the damping materials on the vibration and sound radiation of the low-noise wheel are investigated, and the optimum choices of damping materials are researched. Finally, an improved design based on damping shields mounted on the the steel ring dampers is proposed.