Axisymmetric postbuckling of moderately thick laminated annular plate using FSDT

This work presents axisymmetric postbuckling response of polar orthotropic laminated moderately thick circular and annular plates subjected to uniformly distributed inplane radial compressive load at the outer edge. First-order shear deformation theory (FSDT) is used in terms of deflection w, rotation psi of the normal to the midplane and the stress function phi. These field variables are expanded in polynomials and orthogonal point collocation method is used to discretise the governing equations. The buckling load is obtained by solving a linear eigenvalue problem. Postbuckling loads for different deflections are obtained by solving nonlinear equations by Newton-Raphson method. Clamped and simply supported circular and annular plates with free hole or reinforced by a rigid ring are considered. The results are compared with the classical lamination theory to assess the dependence of the effect of shear deformation on boundary conditions, ratio of Young's moduli, lamination scheme, number of layers, the radius-to-thickness ratio and annular ratio. The response of unsymmetrically laminated plates under inplane radial load is also presented. (C) 2001 Elsevier Science Ltd. All rights reserved.