Compression and low velocity impact response of wood-based sandwich panels with auxetic lattice core

The research determined the resistance to compression and low velocity impact of wood-based sandwich panels, the face sheet made of high-density fiber board, and high pressure laminate, while its auxetic lattice core was made by 3D printing using LayWood bio-composite filament. The core's auxetic property (i.e. exhibiting negative Poisson's ratio) was observed within the planes parallel to the facings. The ability of particular types of multilayer panels to absorb the energy was also determined. Based on the analysis of the obtained test results, it was proven that the core denoted as B, with inclination angle of the cell ribs φx=φy=65∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\varphi }_{x}=\varphi }_{y}=65^\circ$$\end{document}, shows the highest compressive strength. It was determined that the dynamic load causes a very high overload in high-density fiber board face sheets. This results in damage to the sandwich panel surface and core structure. Cells of type B favorably minimize the differences in absorbed energy when using different face sheets and the energy value for low velocity impact. Taking into account the amount of absorbed energy, the most attractive is the panel with the D-type orthotropic core characterized by an inclination angle of the cell ribs φx=30∘,φy=60∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\varphi }_{x}= 30^\circ , {\varphi }_{y}=60^\circ$$\end{document}. The amount of energy absorbed by samples with high-density fiberboard face sheets increases significantly depending on the impactor's energy. For panels with face sheets manufactured from high-pressure laminate, the amount of energy absorbed decreases.