竹材纤维增强材料的特性

着重考察不同竹龄、不同部位毛竹(Phgllochysheterocyclavar.pubscense)竹材剪切强度、抗弯强度和弹性模量的差异,并用电子扫描镜观测断面破坏特征。结果表明:竹材具有明显的纤维增强材料特性,采用纤维增强材料相关的标准进行测试是可行的;不同竹龄的竹材力学性能的变化是由纤维的成熟度引起;竹材力学性能与维管束呈正相关关系,竹材纵向力学性能的差异主要是单位面积维管束的数目差异引起;竹材径向力学性能的差异是由维管束分布和组织构造不同引起;竹材抗弯破坏主要发生在细胞壁的胞间层,破坏特征为单根维管束拔出型;竹材剪切破坏主要发生在次生壁并横穿细胞壁,破坏特征为维管束呈簇状拔出型,并且纤维束从基体中拔出后的表面具有明显的破坏迹象。

Characteristics of Bamboo Fiber Reinforced Materials

The differences of bamboo (Phyllostachys heterocycla var. pubscense) wood of different ages and positions in shear strength, bending strength and elastic modulus were analysed emphatically, and the ultra-structural characteristics of failure surface of bamboo specimens were inspected by scanning electron microscopy(SEM). Results showed that bamboo wood has an evident characteristic of fiber reinforcement, so it is feasible to test bamboo by the criterion for fiber reinforced materials. The changes in mechanical properties of bamboo of various ages arise from the fiber maturity. The mechanical properties of bamboo wood are positively correlated with the distribution of vascular bundles. The differences in longitudinal mechanical properties come from the number differences of vascular bundles on per unit area, and the differences in radical mechanical properties arise from the distribution of vascular bundles and different conformations. The bending failure mainly appears in intercell and intrawall characterized by the pulled out single vascular bundle, while the shear failure of specimens mainly occurs in transwall and intrawall characterized by a cluster of pulled out vascular bundles and the markedly destructive surface of the vascular bundles.