Sharp cracks computations via energy minimization

In this work, we prove that the energy minimization argument is the only essential ingredient for obtaining fracture predictions in a two-dimensional linear elastic continuum, i.e. neither regularization nor additional ad hoc assumptions are necessary to this end. In particular, we show that arbitrary crack paths can be obtained using two fracture potentials for the “sharp model” that are computed in the form of domain integrals starting from a global stationarity condition. The capabilities of the proposed approach are demonstrated with reference to classical benchmark problems of crack propagation in PMMA beams, which provide curvilinear crack trajectories that are strongly dependent from the initial geometry.