LAUSR

Abstract The aim of this study is to investigate the nonlinear response of composite square laminates with different boundary conditions and under compressive loading using experimental, semi-analytical and finite element methods. In order to perform the experimental tests, a new fixture was designed and fabricated for simulation of the nonlinear response of composite laminates. The fixture has the ability to model all kinds of boundary conditions such as simply-support, clamp, and free on longitudinal edges. Nevertheless, in the loaded ends, the boundary conditions are only of clamped type. The desired composite laminates have been prepared with different numbers of layers (8, 12 and 16 layers) and as asymmetrical layup configuration, which finds out-of-plane displacement response as soon as compressive load is exerted. To get the nonlinear results of the composite plates, in addition to experimental results, finite element numerical method has also been used through ABAQUS software alongside another semi-analytical method. In the semi-analytical method, the displacement fields of the plates have been estimated through the first-order shear deformation theory and by Legendre polynomials. Next, through minimum of total potential energy principle, the nonlinear system governing the behavior of the laminates has been obtained and solved. Comparison between all experimental, numerical, and semi-analytical results suggested accuracy of the calculations through the simulations against the experimental results obtained from the new fixture.