NUMERICAL MODELING OF CRACK-GROWTH UNDER DYNAMIC LOADING CONDITIONS

A framework for modeling crack growth is described that is based on in troducing one or more cohesive surfaces into a continuum. Constitutive relations are specified independently for the material and for the co hesive surfaces. Fracture emerges as a natural outcome of the deformat ion process, without introducing an additional failure criterion. The characterization of the mechanical response of a cohesive surface invo lves both an interfacial strength and the work of separation per unit area, which introduces a characteristic length into the formulation. F inite element analyses are carried out for a plane strain block with a n initial central crack, subject to impact loading. The crack is const rained to grow along the initial crack line. Numerical results are pre sented for elastic and elastic-viscoplastic solids using various degre es of mesh refinement.