Meso modelling for composite preform shaping - Simulation of the loss of cohesion of the woven fibre network

The forming simulation of woven reinforcements allows access to information such as the fibre positions after forming, but also the deformation state, as well as the prediction of defects such as wrinkles, yarn sliding and fibre/yarn fracture. The proposed model consists of a mesoscopic description of the reinforcement. It is simple enough to render the simulation of the forming preform possible but describes also properly the main phenomena occurring during the forming. A geometrical model is proposed, where each yarn is modelled using shell elements in contact-friction with its neighbours. A hypoelastic description is used, specific for the yarn behaviour. Identification and validation of the model are done using standard characterisation tests for fabrics. Forming simulations illustrate the capabilities of the proposed approach. A main interest of such modelling is the possibility for the simulation to exhibit large sliding between warp and weft yarns when the tensile loads are too important.