Resonance and vibration cancellation analysis of a vehicle with flexible car body moving over multi-span bridge

To investigate the effect of flexible car body vibration on the dynamic responses of vehicle-bridge system, the dynamic analysis model of a vehicle with flexible car body moving over multi-span bridge was established, and the dynamic responses of the system was computed by Newmark-β method. In the model, the car body was regarded as an Euler beam with both ends free, and the bogie and wheel set were regarded as rigid. The multi-span bridge was regarded as a series of simple bridges and the vibration of the bridge was determined by using modal superposition method. The vehicle and bridge were linked under the wheel-rail corresponding assumption. A series of irregularities were chosen as the system excitation, and the resonance and vibration cancellation of the flexible car body were analyzed. The calculation results show that the vibration of the flexible car body has some effect on the car body dynamic responses, but shows little feedback to the bridge vibration. The flexible resonances of the car body may result in significant amplification of the dynamic responses of the car body, and the flexible resonance speeds are determined by the bogie spacing and the natural frequencies of the flexible car body. Due to the wheelbase filtering effect, when the wave length of irregularity satisfies the condition of vibration cancellation of the flexible car body, the dynamic responses of the car body can be effectively suppressed. ©, 2015, Chinese Vibration Engineering Society. All right reserved.