Developing a homogenization approach for estimation of in-plan effective elastic moduli of hexagonal honeycombs

摘要

In this research, a computational technique is developed for determining effective in-plane properties of hexagonal core honeycombs utilizing homogenization multi-scale technique based on averaging theorems. Purposely associated with engineering constants, specialized unit cells under appropriate boundary conditions are elaborated for two well-known configurations of uniform cell wall thickness and doubled thickness vertical cell walls hexagonal honeycombs. Constant boundary element method (CBEM) are employed for discretizing the boundary integral form of equivalent stress and strain equations and avoiding dependency to the mesh density and elements type selection challenges at cell walls intersection. Comparing with available experimental data for uniform cell wall thickness hexagonal honeycombs, the proposed method validated for a wide range of relative densities. Then comparing with well-defined existing analytical methods which have been previously validated experimentally, the verification of proposed method is done for uniform cell wall thickness and double thickness vertical cell walls. The results show that the proposed methods can present a well approximation of in-plane engineering constants for relative densities lower than 0.3 and also can be applied to higher relative densities by defining proper unit cells where available analytical methods encounter with significant inability.