Analysis of impact response and damage in laminated composite shell involving large deformation and material degradation

A nonlinear finite element analysis of impact response and impact-induced damage in curved composite laminates subjected to transverse impact by a foreign object is carried out.An eight-noded isoparametric quadrilateral shell element incorporating a nonlinear strain displacement relation due to large deflection is developed based on the total Lagrangian approach.The nonlinear system of equations is solved using a Newton-Raphson incremental-iterative method.Example problems of graphite/epoxy cylindrically curved laminates with different curvature are considered and the influence of geometrical nonlinearity on the impact response and the resulting damage is demonstrated.The concurrent effect of material degradation due to impact damage is also investigated.