针对复杂的车桥耦合振动问题,基于D’Alembert原理导出了3轴5自由度车辆的运动方程,考虑了桥面不平度和车辆与桥梁之间的协调条件,推导了车辆与桥梁的相互作用力,基于模态综合理论建立了3轴移动车辆—桥梁耦合振动的微分方程组,编制分析程序并运用HHT方法进行了数值求解。通过算例和某3跨刚架桥的动载试验研究结果验证了该方法的正确性和有效性。对于复杂的多跨桥梁的振型函数可以通过有限元方法求解然后通过插值函数得到,该方法不仅适用于单跨简支梁,也适用于多跨连续梁桥车桥耦合振动问题的求解,具有过程简单,编程方便,计算速度快,且精度很高,特别适合于工程实际问题的计算。
Aiming at the complex problem of vehicle-bridge interaction, the goveming equations of three-axle fivedegree vehicle model were derived based on the D' Alembert' s principle. The interaction forces between the vehicle and bridge were deduced considering the bridge deck roughness and compatibility conditions of the contact points, and computation formula and derivation procedures were presented in detail. Based on the mode superposition theory, the coupled vibration equations were established and solved by numerical program using HHT method. The presented numerical solution method was validated by numerical examples and the dynamic loading test result of a three span rigid frame bridge. The mode shape functions of multi-span continuous bridges can be obtained by finite element analysis and interpolation, so the method can be applied both to simple span bridge and to multi-span continuous girder bridges. The procedures presented are simple and easy for programming. The compiled program runs very fast and the output results demonstrate rather high precision. It is especially fit for computation on practical engineering.