3D interlock composite preforming simulation

In order to simulate 3D interlock composite reinforcement behavior during forming it is necessary to predict yarns positions in the fabric during the preforming stage of the process. The present paper deals with thick 3D interlock fabric forming simulation using specific hexahedral semi-discrete finite elements. Using the virtual work principle, we distinguish the virtual internal work due to tensions in yarns from other internal virtual works. The stiffness relative to yarns tension which is the main part of the rigidity is described by bars within the elements. The other rigidities - like transverse compression, shear strains or friction between yarns - are depicted by a continuous additional material. A combination of this "first order" discrete model and a continuous orthotropic hyperelastic "second order" material formulation will enables us to simulate interlock preforming process. Jointly to the simulation work, we also had to specify and perform experimental testing identification of material's parameters. Theses parameters concern both parts of the model.