Abstract
Anisotropy of wood and wood-based materials are summarized. Wood has characteristic anisotropy arisen from its fibrous structure approximately regarded as three-dimensional orthotropy. Commercial structural lumber is assumed more simply as a two-dimensional orthotropic material for convenience of practical structural design. Anisotropy of wood is a good property for structural members to bear stresses parallel to the wood grain. However, it is undesirable in some other cases. One effective way to modify the anisotropy of wood is to reconstitute wood veneers, pieces, particles or fibers with adhesives. Anisotropic wood, on the other hand, is a satisfactory structural material with no serious trouble, if the structural designers understand its anisotropy and utilize it appropriately. An essential element of using wood as a structural material is appropriate design of structural joints considering anisotropic mechanical behavior of wood.
