竹材的微观结构及其与力学性能的关系

采用宏观与微观相结合的方法,研究了不同种类不同部位的沿壁厚分层竹材的力学性能与生物组织微结构的关系。在扫描电镜内进行试验动态测试,并分析其形态。竹材主要由承力的纤维厚壁细胞和起速接作用并传递载荷的薄壁细胞基体所组成。竹材具有良好的比强度,比刚度,是其厚壁细胞竹纤维排列整齐的结果。在宏观力学性能方面;毛竹高于蒿竹,靠上部大于基部,竹壁外层优于内层,这都是与纤维组织细密、纤维层厚、纤维密度大等因素有关。对竹材生物组织微观结构合理分布和独突优越性的了解,不仅对竹材细胞组织的真实形态有进一步的科学认识,而且对研制竹/塑及其它复合材料增强的有效性和纤维铺层设计都有实际意义,并有助于对不同部位竹材的充分利用。

THE RELATIONSHIP OF MICROSTRUCTURE AND MECHANlCAL PROPERTIES OF BAMBOO

Macroscopic and Microscopic methods were used to investigate the relationship of microstructure and mechanical properties of dif- ferent species and position of bamboo. Comparative tests of tension, compresion, flexural and interlaminar shear wrer carried out for conventional specimen and small scale specimen in SEM. The vascular bundles and fibres is to strengthen, while the parenchyma form the matrix and to transmit stress. Because of the thickwalled fibrous cells are in order array axially, bamboo possess. reasonably good specific strength and specific modulus. As a result of dense fibre tissue, thicker fibrous layer and larger density of fibre, the mechanical properties of phyllostochys bamboo, strips of upper position and walled layer are better than those of Bambusoides, strips of near root and inner layer respectively. The mechanism is explained by fractograph and dynamic failure process. These natural distribution and design may have implication in the development of man-made fibre reinforced composite materials.