Failure surfaces of high-strength materials predicted by a universal failure criterion

Abstract

Advanced high-strength materials including metallic glasses (MGs) and nanocrystalline (NC) metals have attracted great attentions due to their promising mechanical properties. However, since they usually exhibit relatively brittle fracture behavior, a proper failure criterion is urgently required for the safety design of structural components and devices using these high-strength materials. It has been found that the conventional failure criteria may not soundly explain the fracture behaviors of MGs, while the ellipse criterion shows promising universality for well describing the fracture behaviors of several kinds of high-strength materials under various loading conditions. In this study, the principal stress form of the ellipse criterion was derived for the first time, and the two-dimensional failure surfaces according to this criterion were plotted and compared with the other predictions, as well as the experimental and simulation results of MGs and NC metals. The results confirm the applicability of the ellipse criterion for predicting the failure of high-strength materials, and may also improve the understanding of strength and fracture of various materials.