Fatigue Performance of CRTS III Slab Ballastless Track Structure under High-speed Train Load Based on Concrete Fatigue Damage Constitutive Law

The mechanical characteristics of CRTS III (China Railway Track System III) slab ballastless track structure under high-speed train load were analyzed by both the full-size fatigue test and numerical simulation in commercial FEM (finite element method) software Ansys. Considering the damage characteristics of concrete, a concrete fatigue damage constitutive model with the concept of mode-II microcracks for concrete was selected and applied in the FEM model. Based on this model, the fatigue FEM model of CRTS III slab ballastless track system was established and relative numerical simulations were conducted. Also, the simulation results were verified by full sized fatigue test on full sized CRTS III slab ballastless track structure. In addition, through the FEM analysis of CRTS III slab ballastless track structure under fatigue loading, the damage evolution law of CRTS III slab ballastless track structure under high-speed train load was also explored and concluded. It was illustrated that the numerical simulation results by FEM model established in this work was in well agreement with the fatigue test results. Therefore, the relative findings and conclusions from the tests and FEM analysis in this work were able to provide significant references for relevant researchers.