Finite Element Analysis of Out-of-plane Compressive Properties of Thermoplastic Honeycomb

Abstract

Compared to other core materials, honeycomb materials provide impressive mechanical performance for sandwich panels, but with less weight added to the structures. In this article, the out-of-plane compressive properties of the thermoplastic hexagonal honeycombs are investigated by using finite element analysis (FEA). Due to the fact that the vertical cell walls of the honeycombs are not perfectly straight, the out-of-plane compressive modulus and strength cannot be predicted correctly by conventional theories. Therefore, FEA methods are used in this study attempting to evaluate the compressive properties. Initially, linear buckling analysis (eigenvalue problem) is applied on the honeycomb models with various numbers of cells to obtain the relationship between the single hexagonal unit cell and the infinite honeycomb. Based on this, nonlinear large deformation FEA is performed on the unit cell model with/without imperfect geometry to obtain honeycomb compressive properties. Finally, the resulting modulus and strength of the honeycomb are compared to the other analytical results and experimental data. The FEA method shows some advantages over these conventional theories.