Initially rigid cohesive laws and fracture based on edge rotations

We propose alternative methods for performing FE-based computational fracture: a mixed mode extrinsic cohesive law and crack evolution by edge rotations and nodal reposition. Extrinsic plastic cohesive laws combined with the discrete version of equilibrium form a nonlinear complementarity problem. The complementarity conditions are smoothed with the Chen-Mangasarian replacement functions which naturally turn the cohesive forces into Lagrange...