Post buckling behavior analysis of unidirectional saddle shaped composite panels containing delaminations using cohesive zone modeling

In this paper an extensive analysis have been performed on the buckling and post buckling response of unidirectional delaminated composite panels with the different curvatures (zero and 60 degrees of arc’s angle) by means of finite element method. Adjacent plies debonding is simulated by traction–separation law for the geometries containing one and two delaminations through the width and the influence of them on the response of the structure to the compressive loading is investigated. The effect of intact geometry and defective geometry containing delaminations with and without growth capability have been investigated. The complex contribution between nonlinear geometry, material non linearity, and large deformation is considered. Comparing the present results with other literatures in the special case of flat plates, indicates an excellent accuracy. The differences between the global and local buckling response, stable and unstable delamination growth of structures containing one and two delaminations in flat and saddles geometries is compared.