Effect of bending-extension coupling on the deformation of asymmetric laminates
Abstract
Asymmetric laminates may result from delamination and surface damage in symmetric laminates. Linear small deflection laminated plate theory, large deflection theory and finite element method were used to investigate the behavior of asymmetric cross-ply laminates subjected to in-plane loads and transverse loads. The behavior of asymmetric laminates subjected to uniform compression loads and the fundamental frequency of asymmetric laminates with small and large amplitudes were studied. A simple solution was introduced to solve the problem using large deflection theory to correct the deficiency of linear theory. It was shown that for the cylindrical bending problem, the governing equations for large deflection theory could be reduced to linear equations with nonlinear boundary conditions. A finite element plate program based upon Mindlin plate theory and von Karman's large deflection theory were also used to analyze the asymmetric laminated plate. Experiments on cross-ply laminates under in-plane loads were conducted. Comparison of the analytical solution with the experimental data shows good agreement. In recent studies, effects of bending-extension coupling on the deformation of asymmetric laminates were systematically studied to observe problems related to the axial forces, transverse forces, compression forces, and nonlinear and linear vibrations. The results of these studies may provide a basis for further understanding the mechanism of delamination and for analyzing the failure of composite structures. Current developments and observations can be applied to further analyze the crack mechanism for composite structures with delamination stripper and base laminates subjected to in-plane or transverse loads.
Degree
Ph.D.
Advisors
Sun, Purdue University.
Subject Area
Aerospace materials
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