1993 年 42 巻 473 号 p. 132-136
In order to evaluate the effect of minute damages such as slip planes on wood quality, the relationship between some mechanical properties (σt, Et, Wu) and development of slip planes in konara wood (Quercus serrata Thunb.) specimens, which were precompressioned under different percentages of the failing load, was investigated. Furthermore, for the determination of fracture site within the precompression wood under tensile re-loading conditions, the slip plane angle (θp) in the damaged fibers and the inclination angle (θs) of the fracture surface of the cell walls of the precompression wood were measured by a polarizing microscope and the SEM stereo analysing method, respectively.
In the case of the fracture of the precompression wood, it is concluded that cracks almost took place at the slip-plane sites, because the θp and the θs showed fairly good agreement at about 64 degrees. The existence of the slip planes within the wood seriously affected the deterioration of wood quality, especially the decrease of toughness of wood.