Semi-Analytical Buckling Analysis of a Composite Plate with Circular Cutouts on an Elastic Foundation, Under Different Boundary and Partial Edge Loading Conditions

In the present paper, buckling of multi-layer rectangular orthotropic composite plates with two longitudinal or transverse in-plane circular cutouts, on Winkler-Pasternak elastic foundation, is investigated. The analysis is accomplished through two steps. First, the in-plane pre-buckling stress components induced by the partial edge loads are determined and in the second stage, the Galerkin method is employed to develop the governing equations of the buckling. In this regard, the classical theory of plates, von Karman strain-displacement equations, Galerkin and energy approaches, and reduction of the problem to an eigenvalue problem are used. The buckling load is determined based on various relative locations of the cutouts and the: (1) uniform partial, (2) sinusoidal partial, and (3) concentrated edge loads, for the movable simply supported and clamped edge conditions. Furthermore, influence of the elastic foundation of the composite plate is investigated for different concentrated and partial loads. Results reveal that buckling of plates with holes or cutouts is dependent on opposite factors and may occur in local or global forms and the elastic foundation has pronounced effects of on the buckling load. This effect is more noticeable when the partial load is distributed on a larger length of the edge.