多场耦合作用下CRTSⅡ型板式轨道非线性屈曲及动力特性研究

CRTS II slab track is a continuous structure which is longitudinally connected by the precast track slab. The initial damages (such as non-uniform bearing of width joint, interface debonding , open joint, camber and so on) change the force transfer path of track structure，and they may seriously affect the safety and service performance of the track structure. The non-linear buckling and dynamic characteristic of CRTS II slab track under multi-field coupling action of temperature, train load and track damage is a frontier subject need to be solved. Based on the concrete damage mechanics, cohesion theory and nonlinear stability theory, the 3D non-linear buckling finite element model and method of CRTS II slab track considering the effect of track damage will be established to study its mechanism and the main influence factors for CRTS II slab track subjected to the multi-field coupling load and reveal the impact mechanism of typical initial structural damage and material damage on the non-linear buckling deformation. On the basis of the wheel-rail dynamics theory, the 3D wheel-rail coupled vibration model which takes the influence of the temperature and damage into account will be built to research the non-linear dynamic characteristics of wheel-rail system vehicle. The influence of buckling deformation on the dynamic interaction of wheel-rail system will be figured out to evaluate the driving safety and smoothness of high speed vehicle. The results will provide a theoretical foundation for formulating the typical damage maintenance standard and evaluating the safety state of CRTS II slab track.

CRTSⅡ型板式轨道是一种采用预制轨道板纵向连接的连续式无砟轨道。宽窄接缝破损、离缝和上拱等初始损伤改变了轨道结构承力和传力路径，可能严重影响轨道结构的安全服役性能。考虑温度力、列车荷载和损伤等多场耦合作用下的非线性屈曲及动力特性研究是亟待解决的前沿性课题。本项目基于混凝土损伤力学、内聚力理论和非线性稳定性理论，采用有限元方法建立考虑损伤影响的轨道结构空间非线性屈曲分析模型与方法，研究多场耦合作用下轨道结构空间非线性屈曲机理及其主要影响因素，揭示初始损伤、轨道板材料损伤演化对非线性屈曲变形的影响机理；基于轮轨系统动力学理论，考虑温度和损伤影响的耦合作用，建立轮轨空间耦合振动模型，研究轮轨系统非线性动力响应特征，探明轨道结构屈曲变形对轮轨系统动态相互作用关系的影响机制，进而评价高速列车运行的安全性和平稳性。研究成果可为CRTSⅡ型板式轨道典型病害维修标准制定和轨道状态安全评估提供理论依据。

CRTSⅡ型板式轨道是一种采用预制轨道板纵向连接的连续式无砟轨道。宽窄接缝破损、离缝和上拱等初始损伤改变了轨道结构承力和传力路径，可能严重影响轨道结构的安全服役性能。考虑温度力、列车荷载和损伤等多场耦合作用下的非线性屈曲及动力特性研究是亟待解决的前沿性课题。. 本项目基于混凝土损伤力学、内聚力理论和非线性稳定性理论，采用有限元方法建立了考虑损伤影响的轨道结构空间非线性屈曲分析模型与方法，研究了多场耦合作用下轨道结构空间非线性屈曲机理及其主要影响因素，揭示了初始损伤、轨道板材料损伤演化对非线性屈曲变形的影响机理；基于轮轨系统动力学理论，考虑温度和损伤影响的耦合作用，建立了轮轨空间耦合振动模型，研究了轮轨系统非线性动力响应特征，探明了轨道结构屈曲变形对轮轨系统动态相互作用关系的影响机制，为高温季节高速列车运行的安全性和平稳性分析与评价提供了理论支持。. 研究成果可为高速铁路养护维修提供指导作用。