Dynamic Behavior of Metro Train-LSB (Long-Span Bridge) System Considering Nonlinearity of Resilient Wheel

To overall investigate the mechanical performance of resilient wheels to suppress the vehicle-bridge (especially LSB) coupled vibration, the coupled dynamic characteristics of metro train-LSB considering nonlinear resilient wheels are studied. Firstly, the mechanical property test of rubber of resilient wheel is designed and conducted, the mechanical characteristics of the nonlinear resilient wheel (NLRW) and linear resilient wheel (LRW) are discussed, and the dynamic model of LRW and NLRW are established. Then, based on train-track-bridge dynamic interaction theory, the coupled dynamic models of metro train-LSB considering LRW and NLRW are established, respectively. Adopting the established model, the dynamic influences of NLRW and LRW on the metro train-LSB coupled system are investigated by long-short wave irregularity excitation. The effects of damping characteristics of LRW and NLRW on the metro train-LSB system are discussed from the time-frequency domain. Results show that the wheel-rail vertical force of NLRW is smaller than that of LRW. The acceleration of the web, axle box, bogie, and car body of the NLRW is smaller than that of the LRW. The main frequency of wheel-rail vertical force under the action of NLRW and LRW is about 4 and 22Hz. The main frequencies of the rim and web of the NLRW are about 25Hz, while those of the LRW are about 50 and 25Hz, respectively. The acceleration of the web of the NLRW is significantly smaller than that of the LRW. The main frequency of acceleration of the LSB is about 10Hz, and the acceleration of the LSB under the action of NLRW is significantly less than that of the LRW when the frequency is in the range of 22-62Hz. Vibrations of the metro train and LSB increase with the increase of speed, and the dynamic response of the metro train-LSB system under the action of NLRW is smaller than that of LRW.