On the dynamic response of a rectangular sandwich plate with viscoelastic core and generally orthotropic facings

Abstract

This paper explores the effect of facing anisotropy on the damped response to harmonic transverse dynamic loads of a rectangular sandwich plate with a viscoelastic core. The membrane facings are generally orthotropic and the measure of anisotropy is the angle between the geometric plate axes and the elastic axes of the facing material. A Fourier series solution is obtained to the governing plate equations for the case of simply supported edges. The response of the plate at fundamental resonance for several loss factors between 0 and 1 is computed for varying facing anisotropy. It is found that the rotation of facing elastic axes increases maximum lateral deflection, the rate of dissipation of energy and the total strain energy of the core, and decreases the fundamental natural frequency. Increasing loss tangent decreases lateral deflection, but also decreases the rate of energy loss. It is found that the contribution of the core in-plane shear strain energy to the total strain energy is independent of facing anisotropy and loss tangent. For all configurations of facing anisotropy, the lateral response of the plate is insensitive to the change in loss modulus for values beyond 0·7. Typical response curves are shown.