竹节结构及力学性能研究现状

Structure and Mechanical Properties of Bamboo Nodes:A Review of Current Research

竹材优异的柔韧性有利于其塑性加工应用,但在竹材展平或塑性弯曲成型时常常出现开裂现象,尤其在竹节位置,严重影响成品质量。在现行的实验标准中未对竹节处加工进行特别规定,忽略了竹节结构的特殊性及其对竹材整体性能的影响。文章分析了竹节特殊的形态结构、力学性能及其对竹质板材及仿生材料的影响,对比了竹节与节间在结构及力学性能方面的差异,旨在探索更高效的竹材加工方式,提高竹质板材的成品率,为竹质板材的结构设计以及竹材塑性加工提供理论参考。分析显示,竹节与节间在形态结构及力学性能方面均有明显差异,竹节处交错的水平维管束和垂直维管束提高了竹材整体的横向抗拉强度、抗弯强度和抗压强度,增强了竹材纵向承载力和横向稳定性;但对于锯切后的竹条单元,则在一定程度上降低了其顺纹抗压、抗弯和抗拉强度。

The excellent flexibility of bamboo is beneficial to its plastic processing applications,but cracking often occurs during flattening or plastic bending,especially at the position of bamboo nodes,which seriously affects the quality of the finished product.There is no specific regulation for the processing of bamboo nodes in the current standards for experiment,and the special structure of bamboo nodes and its impact on the overall performance of bamboo timber are ignored.The paper analyzes the special morphological structure and mechanical properties of bamboo nodes,as well as their impact on bamboo-based panels and biomimetic materials.It also compares the differences in structure and mechanical properties between nodes and internodes of bamboo,aiming to explore more efficient bamboo processing methods,improve the rate of finished bamboo-based panels,and provide theoretical references for the structural design and plastic processing of bamboo-based panels.The results show that there are significant differences in the morphology,structure,and mechanical properties between nodes and internodes of bamboo.The interlacing horizontal and vertical vascular bundles at the bamboo nodes improve the overall transverse tensile strength,bending strength,and compressive strength of bamboo timber,and enhance its longitudinal bearing capacity and transverse stability,but the sawn bamboo strips have the reduced compressive,bending,and tensile strength along the grain to a certain extent.