A fatigue damage model of concrete structure for ballastless track in high-speed railway

Abstract

A fatigue damage model is established for predicting the response of concrete structure of ballastless track in high-speed railway subjected to cyclic loading using continuum damage mechanics and the concept of bounding surface. The tension and compression bounding surfaces in principal coordinate system are employed in the theoretical model, the damage level under the complex stress state is calculated according the position of the loading surface between the limit fracture surface and the bounding surface, and the varying size of the limit fracture surface is determined through the relation between the accumulative damage and the strain energy release. The fatigue damage model is implemented in the finite software ABAQUS by using the user material subroutine UMAT. It is proven to be reasonable and feasible by the comparison with existing similar models. The fatigue damage evolution of the supporting layer of double-block ballastless track in high-speed railway under cyclic loading is simulated. Results show that the proposed model can not only well reflect the nonlinear evolution law of the supporting layer fatigue damage, but also describe the damage state in its degeneration process. This provide a feasible theoretical method for the fatigue damage analysis of ballastless track in high-speed railway.