基于自由振动的高速铁路简支梁桥共振与消振速度研究  

Research on resonance and cancellation speed of simply supported girder bridge of high-speed railway based on free vibration

作　　者：杨宏印 吴楠昊 曹鸿猷[3] 王波 刘章军 YANG Hong-yin;WU Nan-hao;CAO Hong-you;WANG Bo;LIU Zhang-jun(School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430073,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉工程大学土木工程与建筑学院,武汉430073 [2]桥梁结构健康与安全国家重点实验室,武汉430034 [3]武汉理工大学土木工程与建筑学院,武汉430070

出　　处：《计算力学学报》2023年第5期749-756,共8页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(51708429);武汉工程大学第十三届研究生教育创新基金(CX2021116);湖北省高等学校优秀中青年科技创新团队计划(T 2020010)资助项目。

摘　　要：为研究高速列车简支梁振动的问题,利用移动荷载列解析表达式的极限条件,推导了共振与消振速度。从自由振动幅值的角度,证明了桥梁振动主要由一阶模态贡献,且随着车速的增加,二阶模态对自由振动的贡献逐渐增大,而更高阶的模态贡献量可忽略不计。提高桥梁阻尼能起到抑振的作用,但会加剧车辆驶离桥后的自由振动。以20 m和32 m的两座简支梁桥为算例,从自由振动的幅值和相位出发,阐明了在特定的速度下,发生共振与消振的主要原因是轴载激励的自由振动之间出现叠加、抵消或抑制的现象。当共振速度与消振速度重合时,消振先于共振发生。比较移动轴载解析值与车-轨-桥耦合有限元模型的计算值,结果表明,移动轴载模型能有效预测桥梁的位移时程,但分析桥梁的加速度响应时,有必要考虑车-轨-桥之间的动力耦合效应。To study the vibration of simply supported beams caused by high-speed trains,using the limit conditions of the analytical expressions of the moving load,the resonance and cancellation speeds of the beam are derived.From the perspective of the free vibration amplitude,it is proved that the beam vibration is mainly contributed to by the first-order mode,and with the increase of vehicle speed,the contribution of the second-order mode to the free vibration gradually increases,while the higher-order modes don’t make a contribution.Increasing the damping of the bridge can suppress the vibration,but it amplifies the free vibration after the train leaves the bridge.Taking two simply supported beam bridges of 20 m and 32 m as examples,through the amplitude and phase of the free vibration generated by the axle load,it is clarified that at a certain speed,the superposition,cancellation or suppression of free vibration is the main cause of resonance and cancellation.When the resonance speed coincides with the cancellation speed,the cancellation occurs before the resonance.Comparing the analytical value of the moving load with the finite element result of the vehicle-rail-bridge coupling model,the results show that the moving load model can effectively predict the displacement time history of the bridge,but when analyzing the acceleration response of the bridge,it is necessary to consider the vehicle-rail-bridge dynamic coupling effect.

关 键 词：高速铁路 简支梁 自由振动 共振 消振 阻尼 

分 类 号：U24[交通运输工程—道路与铁道工程] O328[理学—一般力学与力学基础]