摘要
本文研究了常用的毛竹与蒿竹在不同面开缺口的断裂特性。采用常用的和在扫描电镜内的弯曲加载方式,实时观测裂缝动态扩展过程及破坏形式。结果表明:竹材具有良好的断裂性能、断裂韧性 K_(IC)一般比木材高30%。裂缝扩展方向随着竹层径向纤维密度变化而呈现的各向异性程度的不同而异,内层近似各向同性,裂缝呈自相似扩展;外层纤维含量大,呈明显的各向异性,裂缝沿纤维界面方向扩展。扩展过程类似复合材料,分弹性、非弹性、稳定与不稳定四个阶段。从微观结构破坏讨论了竹材的断裂机理。
Bamboo is a species of abundant natural plant materials with highspecific-strength and high specific-modulus.This paper is concerned with fracturebehaviour of Phyllostachys and Bambusoides with notch at different face.Bending fracturetests were carried out for conventional specimen and small scale specimen in SEM.Thecrack dynamic propagation and failure mode are characterized by using SEM.The resultsshow bamboo possess reasonably good fracture properties.The fracture toughess K_(I c) is30% higher than that of wood in general.Crack propogating direction varies with differentdegree of anisotropy along radial.Microstructure failure and fracture mechanism of bam-boo are discussed.
基金
国家自然科学基金 1860360
关键词
断裂
竹材
韧性断裂
bamboo fracture
toughness
microstructure
