Buckling analysis of angle-ply multilayered and sandwich plates using the enhanced Refined Zigzag Theory

The recent enhancement of the standard Refined Zigzag Theory (RZT), herein named the enhanced Refined Zigzag Theory (en-RZT), has extended the range of applicability of the RZT to angle-ply multilayered and sandwich plates. The aim of the present investigation is to assess the numerical performances of the en-RZT for the buckling analysis of angle-ply multilayered and sandwich rectangular plates under in-plane normal loads. The linearized stability equations are obtained using the Ritz method in conjunction with the principle of virtual work, by means of Gram–Schmidt orthogonal polynomials. In order to assess the accuracy of the en-RZT, buckling loads of angle-ply laminated and sandwich plates are evaluated and compared with the numerical results available in open literature. The numerical investigation highlights the high accuracy of the en-RZT in predicting buckling loads. The study contains a parametric analysis aimed to investigate the influence of various design parameters, such as plate aspect ratio, thickness, lamina orientations, in-plane load combinations and boundary conditions on the buckling loads.