In-plane mechanical properties of elliptical cell honeycombs

The in-plane mechanical properties of honeycombs with hexagonally packed elliptical cells are first analyzed theoretically. The theoretical results can be expressed as the product of the mechanical properties of circular cell honeycombs and a cell-geometry coefficient which is a function of the ellipticity of cell walls. The theoretical expressions are then compared with the numerical results obtained from finite element analyses, and they agree well. It is found that the in-plane mechanical properties along the two principal directions of elliptical cell honeycombs are not the same, leading to an orthotropic mechanical behavior. The in-plane mechanical properties of elliptical cell honeycombs depend on the ellipticity of cell walls as well as their relative density. Moreover, a series of design maps for elliptical cell honeycombs with different relative densities and cell wall ellipticities are generated, and can be utilized as a tool in a minimum weight design to satisfy a set of prescribed in-plane mechanical properties.