An asymptotic approach for the analysis of composite plates having interfacial imperfections

An asymptotic method based plate analysis is carried out for composite laminates including interfacial imperfections. By scaling of the thickness coordinate with respect to the characteristic length of the plate, the initial three-dimensional governing equations are separated into the microscopic through-the-thickness equations and macroscopic plate equations. In the microscopic 1D analysis, finite element method along the thickness direction is applied to obtain the deformation modes and equivalent stiffnesses. In order to describe the interfacial imperfection effects, a spring layer model is introduced, which can be easily combined with the existing 1D finite element formulation. From the microscopic analysis, the macroscopic plate equations which take the form of recursive equations are refined maintaining the form of classical plate theory. Herein the present studies, various layups including sandwich plate are taken into account to demonstrate the validity of the present analysis. Since the suggested method can easily and accurately predict the behavior of the composite plate having interfacial imperfections, it can be used as an efficient analyzing and designing tool.