Beyond density: mesostructural features of impact resistant wood

In this study, the impact resistance in the radial loading direction of nine tree species was studied using drop-tower testing, micro-computed tomography, and scanning electron microscopy. It was found that unlike in quasi-static conditions, density alone is a poor predictor of mechanical behavior in wood and that specific mesostructural features (interlocking grain, diffuse porous vessel distribution and intermittent rays) improved impact strength. A new, hierarchical failure of individual tracheids and the bulk fibers resembling progressive delamination of fiber-composites was observed in African mahogany, the most impact resistant tree species tested.
Source: Materials Today Communications - Category: Materials Science Source Type: research