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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。
In this paper, the common bamboo and Artemisia annua in different surface open gap fracture characteristics. Commonly used and in the SEM under the bending load method, real-time observation of dynamic fracture propagation process and the destruction of the form. The results show that bamboo has good breaking properties, and the fracture toughness K_ (IC) is generally 30% higher than that of wood. The direction of crack propagation varies with the degree of anisotropy of bamboo fiber radial fiber density changes, the inner layer is approximately isotropic, the cracks are self-similar expansion; the outer fiber content is large, showing obvious anisotropy, Cracks extend along the fiber interface. Expansion process similar to composite materials, sub-elastic, non-elastic, stable and unstable four stages. The fracture mechanism of bamboo is discussed from the destruction of microstructure.