Wood of trees resists crosswise fracture via complex architecture.


"That construction of lengthwise tubes with relatively modest cross-connections gives wood its spectacular anisotropy…Crosswise, though, most woods resist fracture well, with the highest work of fracture of any rigid biological material; the orientational difference can be as much as a hundredfold (table 15.7). Not only can we use all kinds of intrusive fasteners such as nails and screws without initiating fracture, but a tree can be injured by a crosswise ax stroke and yet not crack in the next storm. A sawyer must cut almost all the way across the trunk before a healthy tree topples." (Vogel 2003:343)

Comparative Biomechanics: Life's Physical World, Second EditionPrinceton University PressOctober 24, 2016
Steven Vogel