A finite strain continuum damage model for simulating ductile fracture in steels

A new coupled plasticity-damage model is proposed within a finite deformation framework for modeling ductile fracture in ASTM A36 structural steels. Damage mechanics principles of effective stress and strain equivalence are employed to formulate a new constitutive model for simulating damage due to the physical processes associated with microvoid nucleation, growth and coalescence. A scalar damage variable is used to track the micro-structural changes that occur during the ductile fracture process. The model is calibrated and validated by comparing its response to the results obtained from experimental testing of four symmetrically and asymmetrically notched ASTM A36 steel specimens. The proposed model is shown to successfully model failure due to ductile fracture under stress states typically observed in structural engineering applications.