Nonlinear analysis of perforated composite plates under compression by experimental, semi-analytical and numerical methods

Abstract

The purpose of this paper is to investigate the effects of different cutout shapes on the nonlinear behavior of perforated composite plates using experimental, numerical and semi-analytical methods and to present their capabilities. For analysis, the composite plates are subjected to a compressive load and different out-of-plane boundary conditions are applied to the lateral edges. Investigations are performed by various methods such as experimental tests, finite element method and a semi-analytical technique. For laboratory tests, a fixture has been designed and built that can create different boundary conditions on the lateral edges of perforated plates and can also test laminates up to 6 mm thick. On laminates, three types of openings are created in square, rectangular and elliptical shapes and the perforated laminates are tested with two types of boundary conditions, including clamped on all four edges (CCCC) and simply on two lateral edges and clamped on two ends (SSCC). These experiments are also simulated in the Abaqus finite element package, taking into account the considerations raised and with the nonlinear Riks method. Also, with similar assumptions in experimental and numerical methods, a semi-analytical method has been developed to compare the results and capabilities of different methods in nonlinear analysis of perforated laminates with different boundary conditions. In the last method, the displacement fields are approximated using Legendre functions and assuming the first-order shear deformation theory. Then, the nonlinear system of equilibrium equations governing the perforated plates is obtained through the principle of minimum total potential energy and is solved by the common method of quadratic extrapolation technique. Finally, the capabilities, advantages and disadvantages of each method, especially the fixtures made for this research, are discussed.