中文摘要：

为提高车—线—桥耦合振动计算的效率,对桥梁结构和轨道结构进行离散,并采用较短的轨道单元得到任意长度组合的轨道—桥梁耦合单元,由此建立基于桥梁施工节段长度的车—线—桥耦合系统有限元模型;采用Newmark-β方法对模型直接积分求解,进行车—线—桥耦合振动分析。采用所建的有限元模型以及对轨道不平顺功率谱密度函数进行逆傅里叶变换生成的任意波长轨道随机不平顺,分析桥上轨道随机不平顺的敏感波长。结果表明：由所建的有限元模型能够得到满意的计算精度和计算效率;当车速大于175km·h^（-1）时,桥梁振动加速度、轨道位移和列车中间车辆1位轮对的轮轨接触力对轨道不平顺敏感的波长均为1～5m,轨道振动加速度对轨道不平顺敏感的波长为0.03～1m,中间车辆车体振动加速度受波长为0.03～1m短波不平顺的影响很小但受其他波长不平顺的影响较大。因此,高速铁路养护维修应重点关注5m以下波长的轨道不平顺。

英文摘要：

In order to improve the computation efficiency of train-track-bridge coupling vibration,both the bridge and track structures were dispersed.With shorter track element,the track-bridge coupling element with arbitrary length combination was obtained.Thus the finite element model of train-track-bridge interaction system based on the segment length of bridge construction was established.The Newmark-βmethod was adopted to work out directly the integral solution of the model for the analysis of train-track-bridge coupling vibration.With the established finite element model and the track random irregularity with arbitrary wavelength generated by the inverse Fourier transform of the power spectral density function of track irregularity,the sensitive wavelengths of track irregularities on bridge were analyzed.Results demonstrate that the established finite element model can get satisfactory computation accuracy and efficiency.When the train speed is greater than 175km·h^（-1）,all the sensitive wavelengths to track irregularities for bridge vibration acceleration,track displacement and the wheel-rail contact force of the first wheelset of intermediate car are 1～5m.The sensitive wavelength to track irregularity for track vibration acceleration is 0.03～1m.The car body vibration acceleration of intermediate car is little affected by the short wave irregumarity with the wavelength of 0.03～1 m but is more affected by irregularities with other wavelengths.Therefore,in the maintenance and repair of high speed railway,the main attention should be paid on track irregularities with wavelengths shorter than 5m.