Predicting Steel Tensile Responses and Fracture Using the Phenomenological Ductile Shear Fracture Model

In the literature, all the micromechanical fracture models used for predicting structural steel tensile responses and fracture are based on the ductile fracture mechanism that uses the Lode angle parameter to simulate shear fracture under low-stress triaxiality. Using the phenomenological shear fracture model that uses the shear stress ratio rather than the Lode angle parameter, this technical note presents the finite element predictions of the responses of S690 steel solid and perforated coupons under tension and of the fractures of TRIP (transformation-induced plasticity) 690 steel specimens under pure shear and combined shear and tension. The calibrated phenomenological shear fracture model parameters are obtained through a phenomenological curve-fitting process that does not involve costly laboratory tests. This technical note demonstrates that the phenomenological shear fracture model can accurately predict the responses and fracture of structural steels under tension, pure shear, and combined shear and tension.