【摘要】 在地震动作用下,铁道车辆可能在桥梁破坏之前发生脱轨,因此铁路桥梁抗震设计应考虑脱轨安全性。用车辆-轨道-桥梁耦合振动分析程序模拟车辆桥上脱轨过程。采用2自由度移动轨道模型,以减少轨道结构自由度数目。为模拟脱轨全过程,轮轨关系在法向接触采用Hertz接触理论,在切线接触采用非线性修正的蠕滑理论。地震动位移时程输入桥梁墩底。用动力增量分析法(IDA)分析地震动强度参数与车辆脱轨指标的关系。以轮轨相对抬升量作为主要脱轨指标,选取一组(5条)地震动记录,对30跨简支梁桥进行的地震下的脱轨分析。数值模拟结果表明:不同的地震输入下,算得的脱轨IDA曲线变化趋势类似,轮轨抬升量大致随地震动幅值呈幂函数形式增加。更多还原

【Abstract】 Railway vehicles may derail on bridges shaken by earthquakes prior to major damages of the bridge itself. Therefor the derailment of vehicles is an important issue in bridge design. An efficient simulation method for the vehicle-rail-bridge dynamic interaction during earthquakes was developed. The simulation model used a simplified rail model with 2 DOFs to improve the computational efficiency. A fully non-linear wheel contact model was used, where the Hertzian contact theory non-linear creepage theory was adopted in the normal and tangent direction respectively. The ground displacements of earthquake records were inputted to the bottom of the bridge piers. The derailment was judged from the uplifts of wheels from the rail. And the uplifts of the wheels were correlated to intensity of the ground motions through the IDA method. The derailments of vehicles on 30 spans of successive simply supported bridges shaken by 5 seismic records were investigated. The uplifts of wheels increase with the earthquake intensities in a trend that approximates the power function.更多还原