Computer simulations of fracture in disordered viscoelastic systems

Dynamics of fracture and its instabilities have been studied using two-dimensional viscoelastic models. Two models have been developed to describe disordered systems, in which the disorder appears as density or mass distribution at mesoscopic length scale. The first model is based on a triangular network of dissipative Born springs and the second model is based on finite element method with a similar mechanism of force relaxation as the first model. Results of computer simulations show a very similar crack branching and velocity oscillation behaviours as found in recent experiments. The mechanisms of branching are discussed. (C) 1997 Elsevier Science B.V.