Investigation of the buckling behaviour of composite laminated plates

The buckling behaviour of rectangular laminated composite plates is investigated employing a global higher-order theory. The displacement field is expanded in the thickness direction in a complete polynomial series with arbitrary degree whereas the series coefficients, function of the in-plane coordinates, are expressed, according to Ritz's method, as a superposition of admissible functions. The elastic and geometric stiffness matrices are obtained from the energy functionals in terms of the generalized coordinates. The problem is suitably nondimensionalized so as to single out the independent parameters. The convergence properties of the adopted discretization scheme are investigated first considering simply supported orthotropic three-layer composite plates under a transverse distributed load. Variations of the lowest buckling loads with the width-to-thickness ratio and with the ratio between the in-plane elastic moduli are also investigated to ascertain the sensitivity of the buckling behaviour with respect to these parameters. Static deflection and linear buckling analysis results are compared with exact 3D elasticity solutions, other laminated plate theories and 3D FE analyses.