| Popis: |
Elastic constants of ray tissue in hardwoods were evaluated by numerical analysis of a simplified cell model. Ray tissue had a Young's modulus in the radial direction (corresponding to the ray's "longitudinal" axis) of 5.5 GPa as compared to an experimental value of 4.5 GPa for California black oak (Schniewind, 1959). The ratios of the radial Young's modulus to the tangential and longitudinal moduli (i.e., the ratios of the "longitudinal" to the "transverse" directions of the rays) were found to be 3.4 : 1 and 1.4 : 1, respectively. These ratios agree approximately with the reciprocals of the degree of anisotropic shrinkage of ray tissue in Japanese beech (Nakato, 1958). |
