Three-dimensional frequency response of the CNT-Carbon-Fiber reinforced laminated circular/annular plates under initially stresses

Abstract

The frequency characteristics of circular/annular plates reinforced with multi-scale hybrid laminates nanocomposite (MHLN) are presented via the state-space formulation based on three-dimensional (3D)-elasticity theory. The circular/annular plate is under initial lateral stress and composed of multilayers with carbon nanotubes (CNTs) uniformly dispersed in each layer, but its properties change layer-by-layer along the thickness direction. With the aid of compatibility conditions, the sandwich structure with two, three, five, and seven layers are modeled. The state-space based differential quadrature method (SS-DQM) is presented to examine the frequency behavior of the current structure. Halpin–Tsai equations and fiber micromechanics are used in the hierarchy to predict the bulk material properties of the multi-scale composite. A singular point is investigated for modeling the circular plate. The CNTs are supposed to be randomly oriented and uniformly distributed through the matrix of epoxy resin. Afterward, a parametric study is done to present the effects of stacking sequence, and various types of sandwich circular/annular plates on frequency characteristics of the MHLN reinforced circular/annular plates using 3D-elasticity theory. As an important consequence, when the value of initial stress increases, the concentration of deformation in the composite disk reduces along the radial direction and intensifies along the circumferential direction.