Damage evolution and dynamic response of cement asphalt mortar layer of slab track under vehicle dynamic load

• Published in: Science China. Technological sciences Vol. 57; no. 10; pp. 1883 - 1894
• Main Authors: Zhu, ShengYang, Fu, Qiang, Cai, ChengBiao, Spanos, Pol D.
• Format: Journal Article
• Language: English
• Published: Heidelberg Science China Press 01.10.2014
• Subjects: Damage; Dynamic loads; Dynamics; Engineering; Evolution; Finite element method; Mathematical models; Mortars; Slabs; Vehicles; 动态响应; 损伤演化; 板式轨道; 水泥; 沥青; 砂浆层; 荷载作用; 车辆模型; vehicle-track coupled dynamics; slab track; statistical damage constitutive model; cement asphalt mortar; damage evolution
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-014-5636-8

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.