Analysis and simulation on fracture of structural steel at elevated temperatures based on extended finite element method

Abstract

This paper presents numerical simulations of fracture behavior of ASTM A992 steels at elevated temperatures using the extended finite element method (XFEM). The XFEM approach has advantages of avoidance of calibrating many material parameters and re-meshing of elements. Two fracture criteria based on maximum principal true strain and stress were calibrated and validated against experimental results, respectively. The calibration and validation results show that the XFEM can predict the fracture mode and engineering stress-strain curves of structural steels at elevated temperatures with reasonable accuracy. The improvement in fracture simulation using XFEM is further verified by a comparison of predicted fracture behavior of steels between the conventional FEM and XFEM. Moreover, it is found from a sensitivity study that the engineering strain and stress of steels at fracture for a given temperature are not sensitive to the stress and strain criteria. Finally, generalized fracture criteria of ASTM A992 steels at elevated temperatures are proposed for numerically simulating steel fracture in ABAQUS by using the average values of calibrated principal true strain and stress at fracture based on test results.