Numerical simulation and application of ductile fracture toughness based on full-range constitutive relationship

Full-range constitutive relationship curves of 26NiCrMoV11-5 steel for steam turbine rotors, stainless steel A508-III and stainless steel 304 were obtained by the FAT (Finite-element-analysis Aided Testing) method using the ANSYS APDL technique. Based on the GTN (Gurson-Tvergaard-Needleman) damage model, reverse finite element method was adopted to simulate the uniaxial tension tests of funnel-shaped specimens by ABAQUS. By calibrating GTN model parameters for the three kinds of material, the simulated results were found consistent with experimental results. Subsequently, the calibrated GTN model parameters were used to simulate the ductile crack propagation behavior of compact tension (CT) specimens made of the said materials. Based on the normalization method, the J resistance curves of the three materials were successfully predicted, and were in good agreement with testing results.