Mechanical and numerical modelling of composite manufacturing processes deep-drawing and laying-up of thin pre-impregnated woven fabrics

Abstract : A new numerical model describing pre-impregnated composite material behaviour is proposed. Elastic and viscoelastic properties of heterogeneous materials are investigated and homogenized on a mesostructural level. The formulation accounts for the large displacements and finite strains involved in the shaping process as well as the mechanical behaviour. A bi-component finite elements to modelling fabric deformation is constructed by combination of two complementary finite element families: membrane finite elements representative of resin deformation, and unidirectional truss finite elements representative of warp and weft fibre deformation. The behaviour of the resin is isotropic viscoelastic but the behaviour of the fibres is isotropic non-linear and results from three deformation mechanisms: straightening, relative rotation and tensile stretch. Experimental shaping tests of pre-impregnated composite by deep-drawing, laying-up and draping are carried out in the laboratory and simulated in order to validate the proposed computational finite element modelling.