中文摘要：

研究目的：由于加固前后铁路简支桥梁自振频率发生变化，车桥系统发生共振时对应的列车速度发生改变，因此需要分析加固前后桥梁的共振响应是否满足要求。本文介绍车桥系统发生共振的原理，研究影响车桥系统共振响应的因素，采用ANSYS软件和多体动力学软件UM（UniversalMechanism）分析加固前后桥梁仿真模型的车桥耦合动力性能。研究结论：（1）对于小跨径直线桥梁，加固前后桥梁发生共振时对应的列车速度发生明显改变；（2）通过桥梁加固，其发生竖向共振时列车速度已经超出高速列车的速度范围；（3）列车第二共振速度时桥梁的竖向振幅和加速度远小于列车处于第一共振速度时，故可以不考虑；（4）对桥梁进行加固，能够明显减小共振时桥梁竖向及横向的跨中振幅和跨中加速度；（5）本研究成果可为简支铁路桥梁的共振控制提供借鉴。

英文摘要：

Research purposes： According to the change of natural frequency of the simply - supported railway bridge before and after strengthening, the resonance speed of train is changed. So it is necessary to analyze the resonance response whether meet the requirements when the bridge is strengthened. In this paper, the resonance mechanism about vehicle - bridge system is introduced, the influence factors of resonance response about vehicle - bridge system are studied, and the dynamic interaction between train and bridge before and after strengthening is analyzed through ANSYS and multi -body dynamics software UM. Research conclusions： （ 1 ） Results of the vehicle - bridge simulation calculation indicate that the resonance speed is changed before and after strengthening of the straight small span bridge. （2） The resonance speed outstrips the normal speed range of high speed train after strengthening of bridge. （3） The vertical amplitude and acceleration of bridge when the train on second resonance speed is much lower than that of the first resonance speed, so it can be ignored. （4） The amplitude and acceleration can be reduced obviously when vertical and transverse bridge resonance occurs according to the strengthening of bridge. （5） The research methods and results can provide references for the resonance control of the simply -supported railway bridges.