Wooden mechanical metamaterials: Towards tunable wood plates

Abstract

One of the biggest challenges in guitar-making is consistency: even though two guitars are made of the same tree, with the same geometry and manufactured with exactly the same techniques, small material variations intrinsic to the wood will make them sound different. We want to address this variability through the structural design of wooden plates used in the manufacture of guitar tops, developing wood-based mechanical metamaterials. By means of simulations, we study the effect of different geometric patterns of holes on the mechanical parameters of a piece of Engelman Spruce, with special emphasis on the density, the radial and longitudinal stiffness, and derived quantities. We show how one can control the elastic properties of perforated wood boards used for mechanical, acoustic and/or aesthetic purposes in general, and not only guitar making. These results could open a new era of rationally designed wood-based panels, for instrument making and beyond.