Long-term evolution model of the train-track interaction considering the concrete fatigue damage constitutive and numerical implementation

This paper integrates continuous damage mechanics and train-track coupled dynamic, a long-term evolution analysis model for the vehicle-track interaction considering the fatigue damage of the concrete materials is proposed, aiming to reveal the evolution mechanicians of the dynamic performance of system induced by the cyclic moving train. First, a spatial elastoplastic fatigue damage constitutive is introduced into the modelling of the vehicle-track interaction, and a numerical scheme based on the operator split method is employed to update the stress state and internal variables of track structure. Then, a consistent tangent modulus of damaged material is derived, and the quasi-static incremental method is applied to obtain the dynamic response of the track considering the material fatigue damage. In addition, a cyclic jump acceleration algorithm based on the damage variable extrapolation and prediction is constructed to achieve the high-cycle fatigue analysis of concrete, and the complete numerical implementation program is given to simulate the long-term behavior. Comprehensive comparisons of the dynamic response, i.e., stress, damage, and displacement, with published literature and ABAQUS model, demonstrate the accuracy and reliability of each part in this work. Finally, the distribution and evolution law of damage values and plastic strain of track under the train are investigated by the numerical examples, and the applicability of the long-term evolution model is elaborated. The wheel-rail dynamic effect is identified as the main internal factor that exacerbates the fatigue degradation of track structure. This work could be beneficial to accurate evaluation of the dynamic behavior evolution of track structure and train, and provides guidance for the maintenance of track structure.