当高速列车通过大跨度桥梁时,地震的发生将对行车安全性产生严重影响.为研究地震作用下车桥耦合系统的动力学响应,车辆子系统由刚体动力学方法模拟,桥梁子系统由一有限元法模拟,轮轨间竖、横向相互作用力分别由轮轨密贴假定和简化的Kalker蠕滑理论定义,以轨道不平顺和人工地震加速度时程作为系统激励,通过大质量法对桥梁子系统施加多点激励的地震作用,采用时程积分和时间步内的力-运动状态迭代求解运动方程,并进行了算例研究.分析结果表明,桥梁加速度响应、列车的脱轨系数、轮重减载率增加随地震烈度增加;常见地震波速下,车桥响应与地震波速之间不存在单调变化关系.
When a high-speed train crosses a long-span bridge,the safety of the train is obviously affected by the occurrence of an earthquake.In order to study the dynamic characteristics of a coupled vehicle-bridge system under seismic loads,the vehicle subsystem was modeled by the rigid-body dynamics method and the bridge subsystem was modeled by the finite element method.The vertical and lateral wheel-rail interactive forces were defined by the corresponding wheel-rail interactive assumption and simplified Kalker creep theory;the track irregularities and calculated seismic acceleration histories were regarded as the system exciter.The seismic effects were imposed as multi-supported excitations to the bridge subsystem by the large-mass method;the motion equations were solved by the history integral method and force-motion iterations within time steps.The results show that the bridge vibration,derailment factors,and offloading factors of the vehicle increase markedly with the seismic intensity;there is no monotonous variation relationship between vehicle-bridge response and the seismic wave velocity.