A numerical study on the effect of delamination on composite cylindrical shells subjected to hydrostatic pressure

This paper deals with the delamination damage and the effect of buckling behavior on delamination propagation of the composite cylindrical shell subjected to hydrostatic pressure. The model of the composite shell with initial delamination and geometric imperfection is elaborated numerically by using the finite element method. The virtual crack closure technique is employed to calculate the strain energy release rate, and the linear fracture criterion is used to determine the onset and growth of the delamination. The buckling deformation and delamination propagation are monitored by performing the nonlinear buckling analysis. In addition, a parametric study is carried out to investigate the influence of the initial delamination shape, area, depth, and ply orientation on ultimate pressure and delamination propagation path. The results show that local or global buckling of the shell promotes the propagation of delamination, and the ultimate buckling pressure of the shell is more sensitive to the axial initial delamination length. The initial delamination shape, depth, and ply orientation have different influences on the ultimate pressure of the shell and the delamination propagation path, and the corresponding explanations are given in this paper.