中文摘要：

采用轮轨时变接触刚度代替轮轨非线性接触力的动力效应,模拟轮轨之间的自然接触状态,将有限元理论和能量变分法用于建立车辆-轨道系统垂向统一方程。通过输入脉冲型短波及中、长波不平顺激励,计算系统的动力响应,验证本文模型的正确性,并与国内常用的轮轨密贴模型进行比较分析。研究结果表明：轮轨密贴模型在分析中、长波不平顺激励工况下的系统动力响应是可行的;但在短波不平顺激励工况下,轮轨之间的刚性处理方法将放大短波激励效应,车轮＂跳轨＂处理方法尚需改进。

英文摘要：

A vertical and unified equation of the vehicle-track system was established with finite element theory and energy variation method, and wheel-rail time-varying contact stiffness replaced wheel-track nonlinear contact force on dynamic effects to simulate the natural contact between wheel and rail. The validity of the model was verified by inputting the long and medium-wave irregularity of track and pulsed shortwave in this model and the dynamic response was calculated. The tight contact model between wheel and rail, which was popular in China was compared and analyzed.The results show that analyzing dynamic response of the vehicle-track system at the tight contact model for the long and medium-wave irregularity of track is feasible. However, the rigid method between wheel and track will amplify the incentive effect of shortwave for the shortwave irregularity of track, the treatment method about jumping rail should be improved.