Mechanical properties of wood disproportionately increase with increasing density

Abstract

Prior work using a large data set has shown that the mechanical properties of wood disproportionately increase with increasing wood density across diverse species, e.g., stems composed of denser wood are stiffer and stronger than stems with equivalent cross-sections composed of less dense wood. However, an alternative approach, introducing the precondition of constant construction cost for the same data set, adduces that for any given construction cost, stems composed of lesser dense woods are stiffer and stronger then stems composed of denser woods. We evaluated these two approaches using generic allometric principles and the same large data set. This evaluation shows that construction costs cannot be constant over an entire ensemble of stems composed of different species of wood. For any specified construction cost (denoted by a k-value), only a particular subgroup of stems is addressed. The conclusions derived for this subgroup cannot be generalized to the entire ensemble of stems composed of different species of wood. Stems composed of denser wood are, on average as stiff and strong, or stiffer and stronger than stems with equivalent cross-sections composed of less dense wood. Denser wood may have a higher carbon construction cost, but its mechanical benefits likely outweigh the extra cost.