Revisiting brittle fracture as an energy minimization problem

A variational model of quasistatic crack evolution is proposed. Although close in spirit to Griffith's theory of brittle fracture, the proposed model however frees itself of the usual constraints of that theory : a preexisting crack and a well-defined crack path. In contrast, crack initiation as well as crack path can be quantified, as demonstrated on explicitly computable examples. Furthermore the model lends itself to numerical implementation in more complex settings.