The industry uses more and more organic matrix composite materials to replace the light metallic alloys. With a strenght/mass ratio superior to the metallic alloys, these materials constitute a real alternative to decrease the weight of the structures. However, the certification of composite structures is a heavy and complex procedure. Virtual Testing consists in replacing a big part of the real essays by numeric simulations to decrease the quantity of physical essays necessary for the certification. However, the models as well as the numerical methods used for the simulations have to be trusted by the certification authorities. Here we focus on the Enhanced Damage Mesomodel which, for twenty years, has demonstrated to be a model capable of taking into account most of the degradation mechanisms of a composite structure. This non linear and non local model is defined at the composite layer scale. The size of the problems generated by a simulation with this type of model is considerable. In this work, special emphasis was put on the numerical treatment of the model. At first, the integration of the model in a simulation code allowed us to improve it. With regards to the resolution method, a domain decomposition method allows the use of the model for the simulation of intermediate-sized structures. The proposed approach allows to surmount the difficulties linked to the use of a not local and not linear model within a method of decomposition of domain.