Abstract
Dynamic fracture in a wide class of materials reveals a “fracture energy” much larger than the expected nominal surface energy due to the formation of two fresh surfaces. Moreover, the fracture energy depends on the crack velocity, . We show that a simple dynamical theory of viscoplasticity coupled to asymptotic pure linear elasticity provides a possible explanation to the above phenomena. The theory predicts tip blunting characterized by a dynamically determined crack tip radius of curvature. In addition, we demonstrate velocity selection for cracks in fixed-grip strip geometry accompanied by the identification of and its velocity dependence.
- Received 3 April 2006
DOI:https://doi.org/10.1103/PhysRevLett.97.134301
©2006 American Physical Society