Free flexural vibration analysis of composite sandwich plate with reentrant honeycomb cores using homogenized plate model

Abstract

The composite sandwich plate with reentrant honeycomb core (CSP-RHC) is a special auxetic composite structure, and the effect of a negative Poisson’s ratio (NPR) on its dynamic characteristics is unclear. In this article, the flexural vibration of CSP-RHC is analyzed based on the 2D homogenized plate model (2D-HPM) using the variational asymptotic method, and the effective plate properties are obtained by homogenizing the unit cell of CSP-RHC. The efficiency and precision of the free flexural vibration results using 2D-HPM are verified by comparison with 3D-FEM results under different boundary conditions, and the influences of the selective parameters on the free vibration characteristics of CSP-RHC are discussed. The results show that the natural frequencies of CSP-RHC decrease with the increase of the aspect ratio, but increase with the increase of the plate thickness and core thickness ratio. The natural frequency of the plate generally decreased with the increased cell angle, regardless of a positive or negative Poisson’s ratio. Furthermore, the natural frequencies of CSP-RHC are obviously lower than that of the traditional honeycomb sandwich plate due to the NPR effect.