Damage evolution and dynamic response of cement asphalt mortar layer of slab track under vehicle dynamic load
Damage evolution and dynamic response of cement asphalt mortar layer of slab track under vehicle dynamic load
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DOI：
10.1007/s11431-014-5636-8
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发表时间：
2014-10-01
影响因子：
4.6
通讯作者：
Spanos, Pol D.
中科院分区：
文献类型：
--
作者：
Zhu ShengYang;Fu Qiang;Spanos, Pol D.
本文研究了板式轨道水泥沥青（CA）砂浆层在车辆动荷载作用下的损伤演化和动力性能。最初，利用连续损伤力学和概率论开发了 CA 砂浆层的统计损伤本构模型。在此模型中，CA 砂浆单元的强度被视为随机变量，遵循威布尔分布。包含应变率依赖性可以考虑其对损伤发展以及粘度和弹性之间转变的影响。与实验数据的比较支持了模型的可靠性。然后使用商业软件 ABAQUS 创建板式轨道的三维有限元 (FE) 模型，其中设计的 CA 砂浆模型作为用户定义的材料子程序实现。最后，基于非线性赫兹接触理论，通过轮轨接触力将垂直车辆模型与板式轨道的有限元模型耦合。研究了在列车与轨道相互作用下，具有各种初始损伤的 CA 砂浆层的损伤演变和动态性能。分析表明，所提出的模型能够预测暴露于车辆动态载荷下的 CA 砂浆层的损伤演变。动态压应变、应变率和诱导损伤随着初始损伤的增加而显着增加，而动态压应力则随着初始损伤的增加而急剧下降。此外，还发现应变率依赖性显着影响 CA 砂浆层的损伤演化和动态行为。
The damage evolution and dynamic performance of a cement asphalt (CA) mortar layer of slab track subjected to vehicle dynamic load is investigated in this paper. Initially, a statistical damage constitutive model for the CA mortar layer is developed using continuous damage mechanics and probability theory. In this model, the strength of the CA mortar elements is treated as a random variable, which follows the Weibull distribution. The inclusion of strain rate dependence affords considering its influence on the damage development and the transition between viscosity and elasticity. Comparisons with experimental data support the reliability of the model. A three-dimensional finite element (FE) model of a slab track is then created with the commercial software ABAQUS, where the devised model for the CA mortar is implemented as a user-defined material subroutine. Finally, a vertical vehicle model is coupled with the FE model of the slab track, through the wheel-rail contact forces, based on the nonlinear Hertzian contact theory. The evolution of the damage and of the dynamic performance of the CA mortar layer with various initial damage is investigated under the train and track interaction. The analysis indicates that the proposed model is capable of predicting the damage evolution of the CA mortar layer exposed to vehicle dynamic load. The dynamic compressive strain, the strain rate, and the induced damage increase significantly with an increase in the initial damage, whereas the dynamic compressive stress exhibits a sharp decrease with the increasing initial damage. Also, it is found that the strain rate dependence significantly influences the damage evolution and the dynamic behavior of the CA mortar layer.