混凝土塑性损伤模型在无砟轨道非线性分析中的应用

Application of Concrete Damaged Plasticity Model to Nonlinear Analysis of Ballastless Track

为满足无砟轨道非线性损伤分析及长期服役性能研究的需求,基于混凝土塑性损伤本构理论和CA砂浆劈裂抗拉试验结果,建立可考虑无砟轨道各组成结构材料非线性损伤的有限元分析模型。主要考虑温度和列车荷载作用,对比分析塑性损伤模型与线弹性模型对计算结果的影响。结果表明:当无砟轨道结构的受力变形较小时,非线性塑性损伤模型与线弹性模型的计算结果相差不大;当无砟轨道升温幅度超过30℃、正温度梯度超过60℃/m或列车荷载大于225kN时,两种模型的计算结果开始产生差异且随着荷载的增大而不断扩大。配筋的塑性损伤模型与现场实际结构和材料属性较为相符,可为无砟轨道非线性分析、塑性变形及损伤累积效应分析、长期服役性能研究等提供参考。

In order to meet the requirements for the analysis of ballastless track non-linear damage and long-term service performance,based on the damage plastic constitutive theory of concrete and the results of splitting tensile test of CA mortar,a finite element analysis model considering the non-linear damage of ballastless track components was established. The calculation results of the plastic damage model and the linear elastic model under the action of temperature and train load were analyzed and compared. The results show that the nonlinear plastic damage model is basically consistent with the linear elastic model when the stress and deformation of the ballastless track structure are minor. When the temperature of ballastless track rises over 30 ℃,and the positive temperature gradient exceeds 60 °C/m or the train load is more than 225 kN,the calculation results of the two models begin to differ and the difference expands with the increase of the load. The plastic damage model with reinforcement in this paper is consistent with the actual structure and material properties in the field. It can be used as a reference for the non-linear analysis of ballastless track,cumulative effect analysis of plastic deformation and damage,and the study of long-term service performance of ballastless track.