Cell size effects on material properties of foam-filled honeycomb sandwich structures using finite element analysis.

Abstract

In recent years, sandwich structures have become used increasingly in many applications, especially in transportation vehicles, due to their high strength-to-weight ratio, excellent thermal insulation, and good performance as water and vapor barriers. The great advantage of sandwich structures is that optimal designs can be obtained for different applications by choosing different materials and geometric configurations of the face sheets and cores. In previous research work, the foam-filled honeycomb cores demonstrate higher stiffness and vibration damping than pure honeycomb and pure foam cores. However, other properties of the foam-filled honeycomb cores have not been investigated thoroughly. In this paper, the effects of honeycomb cell size on both Young’s modulus and the shear modulus of the foam-filled honeycomb core were analyzed using finite element models developed in ANSYS. The polyurethane foam may produce a negative Poisson’s ratio by the use of a special microstructure design. The influence of Poisson’s ratio on the material properties is also presented.