Shear Buckling of Unsymmetrical Cross-Ply Plates

Recently solutions have been obtained [1, 2, 3] for the bending, vibrations, and buckling of laminated plates in which coupling between bending and stretch ing is important. However, buckling results were limited to unsymmetric angle- ply laminates under biaxial compression. Thus, there are no solutions available for the buckling of coupled laminates subjected to shear loading. This paper is concerned with the stability of unsymmetric cross-ply rectangular plates under uniform shear. These composites consist of an even number of layers all of the same thickness and elastic properties with the orthotropic axes of symmetry in each ply alternately oriented at 0° and 90° to the plate axes. Hinge- support boundary conditions are considered. The effect of coupling is ascertained by comparing coupled solutions to those obtained by neglecting the coupling coefficients in the governing equations. Applicability of the reduced bending stiffness approximation to shear buckling of cross-ply composites is also in vestigated.