A micromechanical cyclic void growth model for ultra-low cycle fatigue

The influence of stress triaxiality and Lode parameter on microvoid growth phase of ductile fracture under ultra-low cycle fatigue (ULCF) (N-f < 100, N-f = cycles to failure) loading is investigated using micro-mechanical analyses. A new micromechanical cyclic void growth model (MM-CVGM) to predict the ULCF life of ASTM A992 steels is presented. The MM-CVGM is calibrated and validated from the experiments conducted on axisymmetrically notched specimens. Number of cycles to failure (N-f) and the fracture initiation locations predicted by the model closely matched the experimental observations. (C) 2014 Elsevier Ltd. All rights reserved.