Buckling of Laminated Composite Cylindrical Shells under External Pressure

Abstract

In general, laminated composite structures exhibit some coupling effect due to anisotropy and unsymmetric lamination. Thus, when the number of layers is low, they behave quite differently from the homogeneous orthotropic ones.
In the present paper, the coupling effect on buckling pressure in the cross-ply and angle-ply laminated cylindrical shells subjected to external pressure was discussed based on the analysis by use of the Donnell-type equilibrium equations. The effects due to various factors such as stacking sequence, number of layers, lamination angle and dimension of cylinder, on the buckling pressure were clarified analytically. The principal conclusions are summarized as follows.
(1) As for the effect of number of layers with equal thickness, N, the buckling pressure decreased very much when N is small in both cross-ply and angle-ply laminates because of the variation of cross-ply ratio and the coupling effect, respectively.
(2) As for the effect of lamination angle, θ, in angle-ply laminates, the buckling pressure was minimum at θ=0° and maximum at θ=90° in both symmetric and antisymmetric laminates.
(3) The coupling effect of laminates disappeared rapidly with an increase of the number of layers and their mechanical behavior became similar to that of homogeneous orthotropic laminates.