关键词: 桥梁工程, 车-桥耦合单元, 车轮瞬时脱离, Hertz 接触, 车-桥共振, 动力分析

Abstract: The non-linear Hertz contact theory was adopted and then linearized，and a new vehicle-bridge interaction element considering the transient jump of wheel was derived，which solved the deficiency of the no-jump assumption in the traditional analysis． The dynamic equations of the interaction system were then formulated by means of the“set-in-right-position”rule for formulating matrices，and the combination method and the solution procedure were also presented． Finally the corresponding calculation program was coded，and the proposed interaction element was adopted to analyze an established railway bridge． The results demonstrate that the dynamic acceleration response of the bridge significantly increase and the results of moving loads model are safer under the vehicle-bridge resonance． The abrupt irregularity causes strongly high frequency vibration and makes the dynamic acceleration response of bridge remarkably increase． When there is no jump of the wheel， the result from the proposed method is consistent to the traditional one． But when the jump happens，the proposed method also yields a true result while the traditional one can’t，and the transient jump of wheel has been accurately simulated by the proposed method． The model considering transient jump of wheel should be adopted to analyze the vehicle-bridge interaction and the track maintenance and the deformation control of bridge should be paid more attention．

Key words: bridge engineering, vehicle-bridge interaction element, transient jump of wheel, Hertz elasticity contact, vehicle- bridge resonance, dynamic analysis