TRANSVERSE-SHEAR EFFECTS ON BUCKLING AND POSTBUCKLING OF LAMINATED AND DELAMINATED PLATES

The one-dimensional buckling and postbuckling solutions of unsymmetric laminates with clamped edges subjected to constant membrane strain loads are obtained based on the large deflection shear deformation theory. Closed-form expressions of the critical buckling load and postbuckling deflection have been derived. It is found that both effects of bending-extension coupling and transverse shear deformation will reduce the equivalent bending rigidity and buckling load and increase the postbuckling deformation. These solutions are used to study the behavior of a thin-film strip delamination in a base laminate. The analytic form of energy release rate is obtained by a variational energy principle that shows that the slope of the energy release rate with load parameter will be decreased due to effects of both bending-extension coupling and transverse shear deformation.