A new uncoupled ductile fracture model considering the transition of fracture mechanism

As stress triaxiality increases, the dominant ductile fracture mechanism transitions from shear-dominated behavior to void spherical expansion and necking coalescence. To consider this phenomenon, a new uncoupled ductile fracture model based on the micromechanisms of void nucleation, growth, and coalescence is proposed. The model adopts a piecewise function modeling strategy to account for the transition of fracture mechanism. Through a detailed analysis of the model variables, the physical significance of each parameter are clarified. Moreover, six different materials and two classic fracture models are used for verification of the prediction accuracy of the model, highlighting its advantages and material applicability.