新型二维轮轨耦合单元及OpenSees实现

A Novel Two Dimensional Wheel-rail Interaction Element and Its Implementation in OpenSees

基于轮轨竖向非线性接触关系,提出一种新型通用二维轮轨耦合单元模型,并在有限元OpenSees软件平台上实现。所提单元由轮节点和所有可能与之接触的梁单元节点组成,通过建立和求解关于轮轨作用力的一元三次方程,得到轮轨之间的接触力,计算由轮轨相互作用产生的耦合单元各节点力,定义为单元内力。通过与文献中计算结果对比,验证了该单元模型的准确性和可靠性,基于此模型分析高速列车通过桥梁时在轨道不平顺激励和地震作用下的动力响应。此耦合单元模型易于集成到有限元计算平台中,能与已有的列车模型、轨道和桥梁等模型联合使用,能够考虑轨道不平顺和轮轨脱离等情况,可用来分析复杂竖向车桥耦合系统的动力问题。

This paper presented a novel two dimensional(2D)wheel-rail interaction(WRI)element model for simulating the vertical wheel-rail interaction and implemented the element in a finite element(FE)framework OpenSees.This element consists of a wheel node and the nodes of the beam elements with which the wheel may interact.The WRI force was calculated by solving a cubic polynomial equation related to wheel and rail force.This force was then used to obtain the internal force of the WRI element.The accuracy and reliability of the coupling element model were verified by comparison with the calculation results in the literature,which was then used to analyze the dynamic responses of a high speed train passing through a bridge under track irregularity excitation and subject to an earthquake.Easy to integrate into a general FE software platform,together with FE models of vehicle,track and bridge,the coupling element model is able to be used in nonlinear dynamic analysis of vehicle-track-bridge coupling systems with complexity,e.g.,considering track irregularity and wheel-rail separation.