Shear buckling responses of laminated composite shells using a modified 8-node ANS shell element

In this study a numerical investigation is presented for initial buckling response of laminated composite plates and shells under the combined in-plane loading using a modified 8-ANS method. The finite element, based on a modified first-order shear deformation theory, is further improved by the combined use of assumed natural strain method. We analyze the influence of the shell element with the various location and number of enhanced membrane and shear interpolation. Using the assumed natural strain method with proper interpolation functions, the present shell element generates neither membrane nor shear locking behavior even when full integration is used in the formulation. The effect of various types of lay-ups, materials and number of layers on initial buckling response is discussed. In addition, the effect of direction of shear load on the initial buckling response is studied. The interaction curves (between in-plane compression and shear for different parameters of the laminates) are presented. The numerical results obtained are in good agreement with those reported by other researchers.