Nonlinear dynamic responses of layered skew sandwich composite structure and experimental validation

Abstract

The time-dependent deflection responses of the mechanically excited layered skew sandwich shell panels are computed numerically via a generic model developed mathematically using the higher-order shear deformation theory including the effects of the large displacement. The model includes the large displacements associated with the structural distortion under the small strain regime through Green–Lagrange nonlinear strain kinematics. The derived nonlinear system governing equation is converted to a set of algebraic form with the help of finite element steps. Subsequently, the time-dependent displacement values are computed numerically through the direct iterative technique including Newmark’s integration scheme. The dynamic deflections of the sandwich structural component under the influence of the externally excited mechanical loading are obtained through a generic computer code (developed in MATLAB) via the nonlinear higher-order finite element model. Before the implementation of the proposed model for the sandwich analysis, the solution stability and accuracy have been established by solving different kinds of numerical example from the published domain. Additionally, a few layered sandwich plates of different face sheet layers have been fabricated and the experimental dynamic data are recorded for the comparison purpose with the help of available modal test rig. Finally, the influences of the different structure-dependent design parameters on the nonlinear dynamic responses are investigated using the presently developed numerical model of skew sandwich shell panel, which also reveals that the present results give more accurate results.