Effective Elastic Properties of Honeycomb Cores: High-Fidelity Numerical Validation and Taguchi-Based Sensitivity Analysis

Abstract

Honeycomb composites are extensively utilized in critical applications where weight is a concern in a structure, due to their high efficiency in stiffness-to-weight ratio. In this study, the effective elastic orthotropic behavior of honeycomb composites is analytically expressed as a function of the elastic properties of the constituent sheet material and the geometric parameters of the representative unit cell. Closed-form expressions based on classical beam theory and plate theory are evaluated and systematically validated against a high-fidelity finite element analysis FE-based homogenization benchmark constructed from a representative unit cell with in-plane periodic kinematic constraints. The analytical predictions exhibit generally good agreement with the FE results, with plate-theory-based formulations capturing most elastic constants with higher accuracy. To further support the fidelity of the numerical benchmark, the predicted normalized in-plane moduli are additionally compared with published experimental measurements for aluminum honeycombs, demonstrating close agreement for representative specimens. To quantify the influence of the geometric parameters, a Taguchi-style design-of-experiments (DOE) study reveals that relative density and internal cell angle jointly govern the majority of elastic moduli and Poisson's ratios, while cell height plays a minor role. Furthermore, dedicated parametric studies confirm the cubic thickness-scaling of in-plane moduli (E-1, E-2,G(12)), demonstrating the dominant role of bending-controlled deformation. Together, these results establish a validated, high-fidelity FE homogenization benchmark for assessing analytical formulations and providing design-level constitutive data for optimizing honeycomb core sandwich structures.