中文摘要：

在轨道不平顺激励下,列车过桥时发生车-桥耦合振动.由于轨道不平顺激励源是随机过程,而轮轨接触关系又是非线性的,因此,车-桥耦合振动属于非线性随机振动问题.用统计线性化方法分析车-桥非线性随机振动.轮轨接触几何关系用5个非线性函数描述,推导车-桥系统非线性振动方程.对车-桥非线性振动方程中的非线性函数进行统计线性化,得到时变的线性车-桥耦合振动方程.用虚拟激励法求解线性车-桥系统的随机响应,提出一种＂显式＂统计线性化方法,该法在每个时间步均无需作统计线性化迭代.最后,用Monte Carlo法验证了车-桥统计线性化随机振动分析方法具有较高的精度.算例表明,轮轨非线性接触对车辆和桥梁的随机响应影响很大,车-桥随机振动分析应合理考虑轮轨非线性接触.

英文摘要：

Due to the excitation from the rail irregularity,the vehicle-bridge coupling vibration occurs when rail-way trains traverse the bridge.Since the rail irregularity is random process,and the wheel-rail contact is non-linear,the railway vehicle-bridge dynamic interaction should be classified as the random vibration of nonlinear systems.This study analyzed the nonlinear vehicle-bridge random vibration using the statistical linearization method.This nonlinear wheel-rail contact was described by five nonlinear functions for each wheel-set,and the nonlinear vehicle-bridge equation was derived.By linearizing the nonlinear functions in the vehicle-bridge equa-tion,the linear time variant vehicle-bridge equation was obtained.Then the random responses of the linearized equation were calculated using the PEM method.An explicit linearization method was introduced to cancel the linearization iteration at each integration step of the time-variant system.The proposed method was validated by comparing with Morte Carlo simulations.Case studies show that omitting the nonlinear interaction may in-duce significant errors both in responses of the vehicle and bridge,thus the nonlinear wheel-rail contact should be accounted properly in the random analysis of vehicle-bridge dynamic interactions.