Experimental and numerical analysis of wooden sandwich panels with an auxetic core and oval cells

Wood consumption is constantly being rationalized by the production of modern wood-based materials, especially honeycomb plates. Due to the beneficial properties of the auxetics, wooden honeycomb panels with auxetic cores can be used as structural elements. In particularly as walls and partitions in wooden houses, as well as shelves and bodies for cabinet furniture. Thus the aim of this study was to determine rigidity, strength and capacity to absorb energy in novel sandwich honeycomb boards manufactured from beech wood with oval cells of the auxetic core. Samples with honeycomb boards were subjected to uniaxial compression and three-point bending. Based on testing results it was shown that cores of oval cells exhibited auxetic properties and a strong orthotropy. Density of honeycomb panels is below 400 kg/m3, thus they may be classified as lightweight boards. Thanks to a high value of the modulus of linear elasticity and bending strength the designed board is a good substitute for traditional wood-based panels. During bending honeycomb panels with auxetic cores more effectively absorb energy compared to the same panels subjected to axial compression. These investigations provide the foundation for further studies on optimization of the board structure and its applicability in industrial practice. (C) 2019 The Author. Published by Elsevier Ltd.