Prediction of ductile fracture loci of aluminum alloys and structural steels using Kaeb concept and MSS criterion

Fracture state of a material can be established utilizing a fracture locus as the fracture locus provides equivalent failure strain of a material for different state of stress conditions. A fracture criterion with a small number of calibration parameters is essential in order to identify the fracture locus with a minimum number of experiments. Therefore, in this study, two fracture criteria involving one calibration parameter, i.e., the energy balance (KAEB) concept and the maximum shear stress (MSS) criterion, are implemented to obtain the fracture loci of various metallic materials. Fracture loci of Al 2024-T351 alloy, Al 6061-T6 alloy ASTM A572 Gr. 50 steel, and AISI 1045 steel are predicted, and superiorities and shortcomings of the two fracture criteria are compared and discussed. Results of the current study suggest the use of KAEB concept is more versatile than the MSS criterion as it can capture the non-symmetry as well as both Lode angle and stress triaxiality dominated cases in the fracture locus.