Susumu Chuma, Mitsuji Hirohashi, Toshimasa Ohgama, Yasuhiro Kasahara
Journal of the Society of Materials Science, Japan 40(448) 21-26 1991年
Bamboo is a natural unidirectional fiber-reinforced material and so it is mechanically anisotropic. In this study, the relationship between the Young's modulus in the tangential direction of cylindrical wall within internode and the volume fraction of bundle sheathes Vfor the specific gravity ρ was investigated on two samples of Mousou bamboo. The experimental results obtained are as follows: (1) The Young's modulus in the tangential direction ETincreased parabolically from the inner bark toward the outer bark in the cylindrical wall for both of the samples, and had a tendency of relative increase with height. (2) ETcould be approximated by the next equation. [formula omitted] where, Efand Emare Young's moduli of bundle sheathes and parenchyma, respectively. C is the ratio [formula omitted] of a parallel model. (3) The variation of specific gravity ρ among samples became large with increasing Vfwhen compared at the same Vflevel. This is because the cell diameter of parenchyma differs with samples and the specific gravity increased with decreasing cell diameter of parenchyma. (4) An approximate equation was established between ETand VfConsequently, ETcould be evaluated by the measurement of ρ by means of the linear relationship between Vfand ρ. © 1991, The Society of Materials Science, Japan. All rights reserved.