毛竹节间材与节部材的构造与强度差异研究

竹节是竹子为适应其生存环境长期择优演化而形成的特殊构造,它对提高细长竹子的刚度与稳定性至关重要。但在竹的利用中,竹节对竹材的力学强度是否会有影响,说法不一。现以毛竹为研究对象,在比较了竹节间材和竹节之间的构造差异的基础上,以竹青、竹黄、竹节未处理和已刨平处理的两种试件形式,分析研究了毛竹的含节材与不含节的节间材在强度上的差异。结果表明,无论是自然状态下的竹材试件,还是刨去刨平青、黄、节的竹材试件,竹节对弯曲强度、顺纹剪切强度、抗压强度等力学性能均未见有降低的作用,相反还有着不同程度的增强作用。但竹节对竹材顺纹抗拉强度有着不可忽视的降低影响。

A Study on the Difference of Structure and Strength between Internodes and Nodes of Moso Bamboo

In the utilization of bamboo,it is unknown that whether the nodes of bamboo will change the mechanical strength of the bamboo timber or not.In this paper,the structure of internodes and nodes of Moso bamboo was measured.In addition,the strength of bamboo internodes and nodes were measured using two different categories of samples,namely samples of intact and planed bamboo epidermis,bamboo yellow and bamboo nodes.The results indicated that the bending strength,longitudinal shearing strength,compressive strength of bamboo node samples was not weaker than that of the internodes.On the contrary,reinforcing effects of the nodes were detected.However,the reduction of the longitudinal tensile strength because of the bamboo nodes cannot be neglected.