运用模态综合法的车桥自激激励耦合振动分析

Coupled Vibration Analysis for Self-Excitation Vehicle-Bridge Based on Mode Synthesis Method

针对车桥耦合振动影响自动化码头集装箱小车-低架桥结构安全和使用效率的问题,基于双协调自由界面模态综合法求解了车桥系统在轨道不平顺和轮对蛇形运动自激激励下的耦合振动时域响应,轨道不平顺时程通过Shinozuka一元多维平稳随机过程模拟法从轨道谱生成。用量纲分析法推导了结构动力模型相似条件,设计了试验模型,结合模型试验分析了铅芯橡胶支座、小车速度对车桥耦合振动响应的影响。模型试验与原型仿真结果相互验证表明:模态综合求解车桥耦合振动响应的仿真方法合理;使用铅芯橡胶支座可有效减小车桥加速度响应和支柱反力;车桥加速度响应随着小车速度的增大而增大,系统横向共振临界车速低于竖向车速,临界车速可由简支梁在移动集中力作用下车桥共振条件来估算。

The container vehicle-truss bridge coupled vibration has great effect on the structural safety and handling efficiency in automated container terminal (ACT).To solve this problem,based on free-interface component mode synthesis(CMS) method,the coupled vibration time-domain response,inspired by self-excitation including track irregularity and hunting movement,is solved for the vehicle-truss bridge system.Stochastic simulation of the track irregularity time-history is generated by the Shinozuka′s numerical simulation method of multidimensional homogeneous process.Thereafter,structural dynamic model similarity principle is achieved with dimensional analysis to design a miniature model test.Then the influence of Lead Rubber Bearing(LRB) and vehicle speed on coupled vibration response is obtained.The results of model test and prototype simulation prove with each other,which validate the technique of applying free-interface CMS to solve vehicle-bridge coupled vibration problem,also verifies LRB′s effects on vibration isolation.It shows that the acceleration response increase as the vehicle speed increases.The lateral resonant critical speed of the system is lower than that of the vertical.Resonant critical speed can be estimated by the resonance condition of the simply supported beam under bridge-moving concentrated force.