Dimension reduction model for sandwich panels with novel triangular chiral honeycomb using variational asymptotic method

Abstract

The triangular chiral (Tri-Chi) honeycomb is a novel negative Poisson’s ratio structure, featuring fully triangular cells inspired by the anti-tetra chiral design. This work aims to reveal the deformation mechanisms of the Tri-Chi honeycomb and employs the variational asymptotic method to determine the effective plate properties of sandwich panels with Tri-Chi honeycombs (i.e., SP-TCH). Based on this, a 2D dimension reduction model (2D-DRM) is developed, and the warping functions are solved through asymptotic analysis of the leading terms in the energy functional. Comparative analysis with the 3D FE model demonstrates that the 2D-DRM exhibited maximum errors of only 6.83% and 2.93% respectively in analyzing tension-bending coupling behavior and natural frequency, with the computational efficiencies being improved by approximate 55-fold and 32-fold, respectively. Furthermore, the parameter analysis indicate that the structural stiffness and natural frequencies of SP-TCH were higher than those of stiffened triangle honeycomb sandwich panel with the same dimensions and materials. The facesheet layup design had a significant impact on the equivalent stiffness and vibration characteristics, whereas the included angle had a significant influence on the Poisson’s ratio of the Tri-Chi core layer, leading to a reversal from a negative to a positive ratio as the included angle increased.