Propagation of micro-cracks in viscoelastic materials: Analytical and numerical methods

In the case of micro-cracked viscoelastic materials, the numerical approach is required to solve the problem of crack propagation. The step-by-step method is used to model, using the finite element method, a morphologically representative pattern of the media. The computation of the effective behaviour of the material in the case without crack propagation shows a very good validation with respect to the Burger effective model obtained by the analytical method. The case of crack propagation is solved numerically considering a morphologically representative pattern containing a single crack. We also develop the concept of critical rate of kinematic loading and of asymptotic damage.