Implantation numérique d'un modèle d'endommagement anisotrope non local

ABSTRACT Numerical simulations of concrete structures up to rupture require the use of nonlinear models based on realistic and sufficiently robust physical assumptions. A nonlocal anisotropic damage model is described for quasi-brittle materials such as concrete. The model is written within the thermodynamics framework and introduces only one damage variable (2nd order tensor). To describe the damage evolution, a damage criterion of Mazars type is used. It introduces an equivalent strain computed from the positive part of the strain tensor. To define a nonloncal model, one has to replace it by a nonlocal formulation based on an integral form. The numerical scheme used for the implementation in a F.E. code is implicit, with all the advantages of robustness and stability. However, the constitutive equations of the anisotropic damage can be solved in an exact way on a time integration step. The calculation of the damage is then completely explicit from a programming point of view. Numerical simulations of reinforced concrete structures are presented in order to show the capabilities of the model.