A novel refined dynamic model of high-speed maglev train-bridge coupled system for random vibration and running safety assessment

一种高速磁悬浮列车-桥梁系统精细化随机振动分析新模型及其行车安全评估

Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval.

高速磁浮列车桥上行车是一个多自由车辆-悬浮控制-轨道梁桥耦合的复杂随机动力问题,实现该车-桥系统的精细化模拟是探明其随机振动特性的关键技术。本文基于多体动力学与有限单元法提出了一种精细化数值建模(210自由度/车)的高速磁悬浮列车-轨道梁桥系统空间耦合随机振动分析模型和基于概率密度演化理论的系统随机振动分析方法,可同时考虑多源随机激励的共同耦合作用,车辆、悬浮构架、悬浮磁铁、导向磁铁以及空气弹簧摇杆均为独立运动自由度,桥梁采用实体有限单元法建模,采用精细化非线性电磁力-悬浮间隙实现多点磁-轨相互作用与悬浮控制,研发了高速磁悬浮列车-磁铁-轨道梁桥系统耦合随机振动分析与桥上行车安全评估的计算主程序及其子程序,实现了基于概率保证率的桥上行车安全评估分析,并与蒙特卡洛法计算结果对比验证了该计算模型的可靠性;研究了多源随机激励作用下磁悬浮车辆、轨道梁桥等随机振动响应及其概率密度分布,并开展桥上行车安全性与平稳性分析,以及不同振幅和车速下轨道不平顺波长的系统随机响应敏感性分析。结果表明:列车速度的增加会使敏感波长区间后移,轨道不平顺振幅对敏感波长区间内的响应影响显著。