Comparison of Low-Cycle Fatigue Criteria for the Life Prediction of AISI 316L

This work is a comparative study of the accuracy of criteria for the life prediction of metals under low-cycle fatigue. AISI 316L specimens were tested in strain-controlled conditions, undergoing low-cycle fatigue. Stress and strain tenors developed during one test cycle were calculated through a finite element model. Subsequently, they were numerically elaborated employing four different criteria for life prediction based on strains and on the critical plane theory, namely the Smith-Watson-Topper, the Fatemi-Socie, and the two Chen-Xu-Huang criteria. For each of them, a life prediction was numerically obtained. By comparing the experimental and the numerical results, it was observed that the accuracy of the tested strain-based criteria varies, depending on the principle at their basis. Some of them represent a reasonably reliable prediction tool, while others tend to overestimate the results, but mainly because pure axial loading is a working condition where they are notoriously not effective.