Research on fatigue crack propagation of a T-joint based on XFEM and TSA

The extended finite element method (XFEM) and thermoelastic stress analysis (TSA) are employed to study crack propagation of a T-joint during fatigue testing. The test results of a non-welded T-shaped plate and a welded T-shaped plate are presented in the paper. The theory of XFEM is analysed, and finite element (FE) simulations are conducted to obtain the crack propagation results. The theory of TSA is analysed, and TSA tests are conducted. The temperature change distribution maps, average temperature distribution maps and phase distribution maps of the welded and non-welded specimens in several typical crack propagation stages are presented. The stress intensity factor (SIF) values are evaluated from the TSA maps by regression analysis. The Canny algorithm is employed to detect the crack length based on the temperature change maps of the TSA results. The simulation and experimental results of the XFEM and TSA are compared and summarized.