Calibration and verification of cyclic void growth model for G20Mn5QT cast steel

Abstract

Micromechanical fracture models, such as the cyclic void growth model (CVGM) and the degraded significant plastic strain (DSPS) model, can predict ductile fracture of structural steels under ultra-low cycle fatigue loadings by considering the growth of micro-voids. In this paper, the CVGM and DSPS model were calibrated for G20Mn5QT cast steel through tests and finite element analyses on smooth notched tensile specimens. Double-hole plate specimens of G20Mn5QT cast steel were then tested under different cyclic loadings and corresponding finite element analyses were carried out for the verification of the calibrated micromechanical fracture models. Prediction of ductile fracture by the calibrated CVGM and DSPS model agreed very well with test results.