An insight into the creep-fatigue damage localization in welded joints based on crystal plasticity finite element method

In the present work, a numerical simulation based on the crystal plasticity finite element (CPFE) method is conducted to capture the different mechanical responses and damage in different micro areas of the P92 steel welded joint at 650 °C. A robust Matlab-Abaqus-Python interactive parameter optimization procedure is proposed to identify the constitutive parameters for heat affected zone (HAZ). Good agreement between experimental and simulated stress–strain curves verifies the accuracy of the present approach. Three fatigue indicator parameters are incorporated into the CPFE to capture the damage distribution under low cycle fatigue (LCF) and creep-fatigue interaction (CFI) loadings. The damage accumulation at grain boundaries is observed in the FE simulation. The damage captured by the simulation under both LCF and CFI loadings shifted from HAZ to base zone.