Bamboo—A functionally graded composite-correlation between microstructure and mechanical strength
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Bamboo is supposed to be one of the best functionally gradient composite materials available. In a piece of bamboo, not only the number of fibres (‘vascular bundles’) but also the fibre quality varies from outer to inner-most periphery. It has been observed that near the outer periphery, within 1 mm2 area, the number of fibres is approximately 8 whereas the same at the inner-most periphery is approximately 2. Again the cross-sectional shape of fibre at outer periphery is almost circular (diameter 0.14 mm) and compacted but at the inner-most periphery, a fibre (diameter of major axis 0.93 × diameter of minor axis 0.78 mm) has been sprayed, and contain matrix in it. This structural behaviour causes the variation of tensile strength, e.g., the strength of a fibre at the outer periphery is about 160 kg/mm2 and the same at the inner-most periphery is only 45 kg/mm2. It has also been observed that the matrix of bamboo can preferentially be removed from the fibre by alkali treatment. 10% NaOH can remove adhered matrix with little effect on fibres while 20% or stronger alkali reduces the strength of fibre.
KeywordsPolymer Microstructure Tensile Strength Composite Material Mechanical Strength
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- 1.S. SAHA and S. PAL, “Concise Encyclopaedia of Composite Materials” (Pergamon Press plc., Headington Hill Hall, Oxford OX3 OBW, UK, 1989) p. 243.Google Scholar
- 3.S. JAIN, U. C. JINDAL and RAKESH KUMAR, ibid. 12 (1993) 558.Google Scholar
- 4.S. LI, Q. ZENG, Z. ZHENG, F. ZHANG and B. ZHOU, report No. PB94- 208477/XAD, Gov. Res. Announe. Index pp9; ISSN:0097-9007, Publication date 1992 (EMA Journal Announcement: 9504).Google Scholar
- 5.S. JAIN and R. KUMAR, Mater. Manuf. Process. 9 (1994) 813.Google Scholar
- 7.S. AMADA, Y. ITIKAWA, T. MUNEKATA, Y. NAGASE and A. KIRIGARI, in Proc. 5th Bioengineering Div. Conf., Jpn. Soc. Mech. Engg., 1993, p.62.Google Scholar
- 8.B. ZHOU, in 6th Workshop on Physics of Materials-frontiers of Advanced Materials, Physics and Technology, Shenyang, Peoples Republic of china, 1992, J. Mater. Sci. & Tech. (China) 9 (1993) 9.Google Scholar
- 9.QIYUN ZENG, SHIHONG LI, BENLIAN ZHOU and FUHE CAILIO XUEBAO, Acta Materiae Compositae Sinica 10 (1993) 1.Google Scholar
- 12.S. AMADA, Mater. Res. Soc. Bull. 20 (1995) 35.Google Scholar