Modeling impact induced delamination of woven fiber reinforced composites with contact/cohesive laws

The dynamic delamination in woven glass fiber reinforced plastic (GRP) composite is studied with a 3D finite deformation an-isotropic viscoplastic model in conjunction with contact/cohesive laws. The large deformation of the material during impact loading is described through an anisotropic plasticity model in total Lagrangian co-ordinates whose coecients are determined experimentally. The interaction between lamina is analyzed through a contact/interface model. The tensile and shear tractions in zero thickness in-terface elements, embedded between lamina, are calculated from interface cohesive law. The interface cohesive law describes the evolution of these tractions in terms of normal and tangential displacement jumps and other interface parameters. The compressive traction at the interface is calculated through the impenetrability condition employed in the contact module. Once the eective dis-placement jump exceeds a specified critical value, the interface elements are assumed to have failed, i.e., delamination is said to have taken place. Three interface cohesive laws are proposed to describe the delamination process. It is assumed that loading of interface takes place reversibly up to a specified value of the displacement jump followed by irreversible loading beyond this value. This feature represents a partial damage of the interface in the event of unloading. Dynamic delamination in the woven GRP composite is studied through analyses of plate-on-plate impact experiments. The heterogeneity of composite materials leading to wave dispersion and scattering is modeled by considering a layered composition of the GRP plate. Each lamina is assumed to be made of three layers of materials. The middle layer of half the thickness of lamina is considered as GRP and the two end layers of equal thicknesses ar