铁路列车-轨道-基础结构动力相互作用统一分析PartⅡ:混凝土车致疲劳损伤与空时演化  

Unified analysis for railway train-track-substructure dynamic interaction Part II:train-induced concrete fatigue damage and temporal-spatial evolution

作　　者：徐磊[1] 余志武 XU Lei;YU Zhiwu(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075

出　　处：《铁道科学与工程学报》2023年第2期385-392,共8页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52008404,U1934217);中国中铁重大专项(2020-Special-02);中国科学青年人才托举工程项目(2020-2022QNRC002);湖南省自然科学基金资助项目(2021JJ30850,2022JJ20071);省部共建交通工程结构力学行为与系统安全国家重点实验室开放课题(KF2022-09);广西防灾减灾与工程安全重点实验室开放课题基金资助项目(2022ZDK016)。

摘　　要：铁路工程混凝土结构疲劳损伤演化的数值实现是列车-轨道-基础结构系统动态性能预测的重要基础。基于车辆-轨道耦合动力学基本原理,引入混凝土疲劳损伤本构和砂浆黏弹性-疲劳本构,基于已建立的列车-轨道-基础结构动力相互作用模型为基础,在铁路工程系统动力学框架内建立了列车循环作用下无砟轨道混凝土结构疲劳损伤动力演化计算模型。在所建立的演化计算模型中,以材料疲劳损伤本构为控制条件,根据结构有限单元应力/应变点的加/卸载、受拉/受压状态实时更新混凝土结构和砂浆层的刚度表征矩阵,将上一次列车作用下的混凝土结构疲劳损伤及残余变形作为下一次列车-轨道-基础结构系统动力学方程的初始条件之一,实现系统空间振动与疲劳损伤演化的耦合时变分析。数值计算结果表明:本模型有效揭示了砂浆层疲劳损伤的三阶段发展特性;轨道板和砂浆层的疲劳损伤发展速率、最不利损伤方式、位置和形式等存在显著差别;轨道板和砂浆层疲劳损伤对车辆-轨道系统动力响应的影响主要出现在疲劳损伤的后期发展阶段。Numerical realization of fatigue damage evolution of concrete structures in railway engineering is a necessity for predicting dynamic performance of train-track-substructure systems. Based on the principle of vehicle-track coupled dynamics, this paper introduced concrete fatigue damage and mortar viscoelasticity fatigue constitutive models and the train-track-substructure dynamic interaction model established in the previous work.The dynamic evolution model of fatigue damage of concrete structures for ballastless track subjected to the cyclic effects of the train was established. In this model, the material fatigue damage constitutive model was used as the control condition, and the stiffness characterization matrix of the concrete structure and the mortar layer was updated in real time considering the loading/unloading, tension/compression state of the stress/strain point of the finite elements. The fatigue damage and residual deformation of the concrete structure under the action of the previous train were taken as one of the initial conditions of the dynamic equation of the next train-tracksubstructure dynamic interaction, and the coupled time-varying analysis of the spatial vibration and fatigue damage evolution for this unified system was realized. The numerical results show that this model can effectively reveal the three-stage development characteristics of the fatigue damage of the mortar layer;there are significant differences in the fatigue damage evolution rate, the most unfavorable damage mode, location and form of the track slab and the mortar layer;and the influence of structural fatigue damage on the dynamic response of the train-track-substructure system mainly occurs in the last development stage.

关 键 词：铁道工程 动力相互作用 混凝土疲劳损伤 本构关系 动力迭代 动力演化 

分 类 号：U211.1[交通运输工程—道路与铁道工程]