A Consideration on Stress Relaxation of Wood Cell Wall

Autor: MORI, Mitsumasa, NORIMOTO, Misato, YAMADA, Tadashi
Jazyk: angličtina
Rok vydání: 1974
Zdroj: Wood research : bulletin of the Wood Research Institute Kyoto University. 56:33-48
ISSN: 0049-7916
Popis: The experiments on tensile stress relaxation in radial direction for wet Hinoki, Hoonoki, Akamatsu, Keyaki and Shirakashi were carried out at the stress levels of 30 and 80 % and at the temperatures of 20, 35, 50 and 65℃. The relaxation curves of cell wall were estimated and were analyzed by TOBOLSKY-EYRING reaction rate theory. The results were summarized as follows: (1) The stress relaxation curves of wood and cell wall were almost linear up to ten minutes at all temperatures and stress levels. (2) Assuming that the stress acting on cell wall decays completely, the values of 73 and 61 kcal/mole as the free energy of activation in the relaxation process were obtained at the stress levels of 30 and 80 % respectively. On the other hand, assuming that the stress acting on cell wall does not relax completely and converges to a definite value, the values of 36 and 32 kcal/mole were obtained at the stress levels of 30 and 80 % respectively. The latter values were comparable to those of cotton plied yarns calculated by FUJITA et al. (3) Considering that the average distance H is constant, the number of parallel flowing units in a square cm of cross section perpendicular to the stress N was proportional to the stress and was inversely proportional to the temperature. These results show that the arrangement of parallel flowing units becomes better to the direction of the stress applied with increasing stress and with decreasing temperature.
この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。
Databáze: OpenAIRE
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