移动荷载下简支梁桥3种车桥耦合模型研究

依据振动理论和欧拉-贝努利梁假设,推导了简支梁在移动车轮加簧上质量模型、四分之一车模型和二分之一车模型3种不同车辆模型与桥梁系统竖向振动微分方程.采用模态叠加的离散化方法,将偏微分方程转化为变系数常微分方程,并将微分方程数值积分的Runge-kuntta方法引入到该时变系统的振动响应中来.结果表明,3种车辆模型都可以反映出移动荷载作用下车桥耦合振动的总体规律,但考虑车体刚度的影响更能体现车桥耦合振动的真实性.

Comparison of Three Models for Vehicle-bridge Coupled Vibration of Simple Beam Bridge Subjected to Moving Load

In this paper,three models for vehicle-bridge coupled vibrations, namely moving spring mass system,two-degree-of freedom vehicle model and fourdegree-of freedom vehicle model were derived according to vibration theory andthe hypothesis of Euler-Bernulli beam.Through using modal analysis method,thepartial differential function was changed to differential function which varied with time.Based on Runge-Kutta method,the vehicle-bridge coupled vibration eation were solved with MATLAB.The results show that the three models all can reasonably reflect the rule of bridge vibration under moving loads.However,more authentic results can be obtained with taking the vehicle body rigidity into account.