连续梁桥跳车冲击下车桥耦合振动响应分析

Analysis of vehicle-bridge coupling vibration response ofcontinuous beam bridge under vehicle jumping impact

为研究车辆在不同工况下发生跳车对变截面连续梁桥动力响应的影响,文章选用1/4车辆模型,采用D’Alembert原理建立车辆振动平衡方程;基于Euler-Bernoulli梁理论将变截面连续梁划分成多个微段并进行受力分析,建立桥梁振动平衡方程,采用模态坐标法考虑振型的正交性对方程进行简化,与车辆振动方程联立得到车桥耦合振动方程,最终理论推导出跳车冲击过程中的车桥耦合振动平衡方程;利用MATLAB自编程序求解车桥耦合振动方程,得出车桥耦合动力响应。研究表明:当跳车高度不断增加时,桥梁动力响应持续加重,位移最大值逐渐增加;当不同桥跨跨中发生跳车时,跳车跨位移响应最大,距离跳车跨越远,位移响应越小。

In order to study the influence of vehicle jumping on the dynamic response of variable cross-section continuous beam bridge under different working conditions,the 1/4 vehicle model is selected,and the vehicle vibration balance equation is established by D’Alembert principle.Based on the Euler-Bernoulli beam theory,the variable cross-section continuous beam is divided into several micro-segments and the force analysis is carried out.The bridge vibration balance equation is established.The modal coordinate method is used to consider the orthogonality of the vibration mode to simplify the equation.The vehicle-bridge coupling vibration equation is obtained by combining with the vehicle vibration equation.Finally,the vehicle-bridge coupling vibration balance equation in the process of vehicle jumping impact is derived theoretically.MATLAB self-compiled program is used to solve the vehicle-bridge coupling vibration equation,and the vehicle-bridge coupling dynamic response is obtained.The results show that when the jump height increases,the dynamic response of the bridge continues to increase,and the maximum displacement increases gradually.When the jump occurs in the middle of different bridge spans,the displacement response of the jump span is the largest,and the displacement response is smaller when it is far away from the jump span.