Young's Modulus of Cell Wall for Coniferous Wood
Young's Modulus of Cell Wall for Coniferous Wood
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针叶木细胞壁杨氏模量
DOI：
10.1678/rheology1973.9.4_169
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
F. Tanaka
中科院分区：
文献类型：
--
作者：
M. Norimoto;T. Ohgama;T. Ono;F. Tanaka
细胞壁纵向杨氏模量与木材的抗弯性能密切相关，其在树种间和同一树种内的差异都很大。为了解释这一观察结果，我们测量了许多软木品种的杨氏模量，结晶度和微纤丝角。细胞壁平均动态杨氏模量的实验值为4.5 ~ 1011 dyn/cm ~ 2 ~ 6.4 ~ 1010 dyn/cm ~ 2。该模量值极低的物种表现出低的结晶度和大的微纤丝角。另一方面，杨氏模量的细胞壁的理论上估计使用细胞壁模型，其中的化学成分和微纤丝角的细胞壁层中的分布被考虑在内。根据这一理论，考察了结晶度、微纤丝角和基体弹性常数对胞壁杨氏模量的影响。结果表明，细胞壁的杨氏模量对微纤丝角有很强的依赖性，微纤丝角的变化是造成不同种类细胞壁杨氏模量和弯曲质量差异的主要原因。
Young's modulus of the cell wall in longitudinal direction, which varies widely not only among the different wood species but also within the same species, is closely related to the bending quality of wood. In order to explain this observation, we made measurements of Young's modulus, crystallinity and microfibril angle for numerous softwood species. The experimental values of the average dynamic Young's modulus of the cell wall ranged from 4.5•~10 11dyn/cm2 to 6.4•~10 10dyn/cm2. Species having extremely low value of this modulus showed low degree of crystallinity and large microfibril angle. On the other hand, the Young's modulus of the cell wall was theoretically estimated using a cell-wall model, in which the distribution of chemical constituents and microfibril angles in the cell-wall layers are taken into account. The effects of crystallinity, microfibril angle and elastic constants of matrix on the Young's modulus of the cell wall was examined according to this theory. From these results it was proved that the Young's modulus of the cell wall depend strongly on microfibril angle and that the main reason for the variation of the Young's modulus of the cell wall and the bending quality among the different species is resulted from the variation of microfibril angle.