Study of fracture mechanisms on low carbon steel under different biaxial loading states using an Arcan type device

Abstract

This work aims to study the fracture mechanisms of a low carbon laminated steel under different biaxial stress states employing a universal testing machine with an Arcan type device. The chosen material was an AISI/SAE 1020 steel. A specific butterfly specimen geometry was designed with the aid of finite element simulations to concentrate critical stresses at the center of its neck. The Arcan device can change the specimen’s orientation regarding the machine loading axis, generating different biaxial stress states. Tests were carried out on pure tension (0º), combined stress with a predominance of shear stress (60º), and pure shear (90º). An evident deformation was observed in the microvoids generated in the specimens at 60º and 90º, orienting them in the direction of the shear stress, favoring their coalescence and decreasing their mechanical resistance. Although no apparent difference was observed between the failure surface morphologies of the specimens loaded at 60º and 90º, an evident difference was observed concerning the sample at 0º due to the dominant presence of shear stress.