Mathematical Sciences Department Colloquium: Michael Smith, WPI

Title: Separating propagation and nucleation in fracture mechanics

Abstract: We briefly review Griffith fracture and discuss how it fails to meet certain physically motivated criteria, then review the strength surface and the experimental observation that it must be independent of other criteria. We discuss recent attempts at modeling this independence by way of a so-called driving force. We demonstrate that, as is, such models cannot approximate sharp models that allow for unbounded stresses, a phenomenon that must occur near crack tips as a consequence of linear elasticity. We then introduce a class of models that allow for an arbitrary strength surface while being able to model unbounded stresses.