将桥梁简化为两端简支的欧拉-伯努利梁模型,考虑两自由度车辆移动系统,以桥面结构表面不平度功率谱密度函数作为输入,建立了多个移动车辆系统-桥的耦合力学分析模型。通过状态空间理论和演变随机过程一般理论,应用模态分析法,给出了整个车-桥耦合系统演变随机响应的求解方法,推导得到了桥梁截面位移和截面弯矩均方值响应和演变功率谱密度函数的理论公式,并结合算例分析,讨论了在不同桥梁跨度、不同桥面等级、不同车辆移动速度下桥梁跨中位移均方根值响应的变化规律。
The coupling random vibration of vehicles-bridge is studied.The bridge and vehicle are modeled as a continuous Euler-Bernoulli beam simply supported at the both end and a two-DOF system with linear suspensions and tire flexibility respectively.The power spectral density of bridges surface irregularity is taken as input.According to state space theory,general evolutionary random processes and modal analysis,the mean square values and evolutionary power spectral density functions of bean-displacement and section moment are derived.The effects of bridge span,road surface roughness and vehicles speed on the root mean square of the deflection at the middle of beam are discussed.