A Finite Element Approach for Inter-Laminar Damage of the Carbon Fiber Reinforced Polymer due to Impact

Composites reinforced with carbon fibers are widely used in automotive, aviation, nautical, in the blades structure of the wind turbines. Composite structures shows outstanding mechanical properties at static and cyclic behavior but the impact damage represents a problem extensively studied because during and after impact local damage and interlaminar fissures occur which cannot be detected easy. As a result, the experimental and theoretical approach to impact behavior of composites is a method of diagnosis and prognosis of phenomena that develop as a result of shock stresses. The paper focuses on the finite element modeling of the composite plate made of twelve layers which are arranged at an angle of 45° to each other, thus obtaining a quasi-isotropic material. The impact of the plate with low energy was simulated, resulting the equivalent stresses von Mises, shear stresses and deformations of each layer. It was found that the variation of stresses von Mises on the thickness of plate is linear and the shape and magnitude of the delamination developed in each layer depend on the difference between stiffness of the successive layers and rigidity of the interface between layers. The FEM results were confirmed experimentally. The novelty of the paper consists of the plate modeling as a multilayers structure and the simulation of impact with low energy. It were analyzed the shapes of strains from each layer and compared with experimental results.