A specific 3D shell approach for textile composite reinforcements under large deformation

The deformation of textile composite reinforcements is strongly conditioned by their fibrous composition. Standard plate and shell theories are based on kinematic assumptions that are not verified for textile reinforcements. A 3D shell approach specific to fibrous reinforcements is proposed. It is based on two specificities: the inextensibility of the fibres and the possible slippage between the fibres. The approach is developed in a continuum-based shell element. The form of the virtual work reflects the specificities of the deformation of the fibrous reinforcements. It takes into account the tensile and bending stiffness of the fibres. Friction between fibres is taken into account in a simple way in connection with bending. The present approach is based on the actual physics of the deformation of the textile reinforcements. It makes it possible to simulate the 3D deformations of textile reinforcements and provides displacements and strains for all points in the fabric thickness and the proper rotations of the material normal.