1993 年 42 巻 473 号 p. 137-140
Firstly, we investigated the effect of reverse load on creep of wood during drying. Secondly, we examined the restoration during adsorption of bending set wood, which had been dried under three different loading conditions: (1) normal bending-load was applied in the range of 30-17% moisture contents (MCs), (2) reverse bending-load was applied in the range of 17-7% MC, (3) normal bending-load and then reverse bending-load were applied.
The results are summarized as follows.
(1) When the reverse bending-load was applied during drying, creep became greater than that in the condition when the normal bending load was applied again. This suggests that the reverse load stimulated the recovery of the normal set developed just before in the limited narrow range of MC.
(2) When the restoration curves of bending set wood during adsorption under loading conditions (1), (2) and (3) are referred to as M, P and K, respectively, the curve K was closely similar to the resultant curve by the superposition of the curves M and P. Therfore, the set developed at the higher levels of MC and that at the lower level of MC are almost independent each other, although not completely independent from the result of (1).