拟“车-桥耦合系统”的动态近似分析法

目前对于车体通过桥梁的动力响应问题,通常是将车辆子系统和桥梁结构耦合为一个系统,同时进行分析.文中提出一种近似但具有足够精度的方法用以计算车-桥耦合系统的动力响应.将车-桥耦合方程分解为两个部分,忽略作用在桥梁上的由移动车辆产生的惯性力项,只剩下移动力项.计算出桥梁在移动力作用下的响应,并把此响应作为车体动力响应的激励源反馈给车体,从而计算出车体的响应.从数值计算的角度,采用MATLAB编程并与车桥耦合系统精确的数值解作对比,验证了轻车过重桥情况下本文方法的可行性.通过分析表明,此方法能避免车-桥耦合系统计算时的庞大运算.

Dynamic Approximation Method for Quasi-VBI System

In studying the dynamic response of a vehicle moving over a bridge, researchers may encoun- ter to update and factorize system matrices for both the vehicle subsystem and the bridge structure at each time step in a time history analysis, which is a laborious work in numerical computations. This paper intends to propose an approximate and enough accurate method to compute the response of the vehicle-bridge interaction （VBI） system. First, the coupled equations of the VBI system are decom- posed into two independent parts, in which the inertia force induced by the moving vehicle acting at the bridge is neglected and only the moving force travel along the bridge is considered. Second, the bridge response under the moving force is computed and feedback to excite the running vehicle so that the vehicle＇s response can be determined. When the bridge is much heavier than the vehicle, good a- greements can be observed between the results calculated by the present method and the exact ones of VBI system in the numerical example. It turns out that the proposed method can avoid the huge calcu- lation of the VBI system, and can be a simple alternative for evaluating the responses of a real VBI system.