Yield criterions of metal plasticity in diffierent stress states

Abstract

Five types of tensile tests were conducted to study the yield behavior of 2A12-T4 aluminum alloy. Parallel finite element models were built for each test and solved with ABAQUS with diffierent yield criterions. The result shows that any of the four criterions: von Mises yield criterion, Tresca criterion, Twin-Shear criterion and von Mises criterion with hydrostatic pressure correction, overestimates the yield strengths of the specimens. Rather than hydrostatic pressure, Lode stress parameter is the key factor that affiects the diffierences between experimental and simulation results. Based on this concept, a new yield model with Lode dependence modified from von Mises criterion is postulated. Although one more parameter needs to be confirmed, the simulation results of this yield model are better than those of other criterions. © 2009 The Chinese Society for Metals.