The Research Of Morphology And Tensile Mechanical Properties Of MOSO Bamboo Vascuar Bndle

Bamboo is composed by vascular bundle and parenchyma, and the mechanical properties of bamboo are provided mainly by the vascular. Vascular bundle is an important connecting of the microscopic properties and the macroscopic properties of bamboo. This paper got the vascular bundles in different parts by the mechanical stripping method, then determined the composition and areas of vascular by the Confocal Laser Scanning Microscope; at last measured the tensile strength and elastic modulus by the Mechanical Testing Machine.Meantime through the performace of vascular discussing the various vacomponents on the contribution of vascular performance.Bamboo from the outside to inside, the vascular morphology gradually changed from the semi-open to open. Outer layer was semi-open, and the inner layer was open. Outer layer vascular bundles were staggered arrangement tightly, and the vascular areas changed regularly. On the contrary, the inner layer vascular bundles were distribute uniformly, while the areas of vessel and porous were lager, so the areas of fibrous sheath were smaller.Measured the tensile strength and elastic modulus by the Mechanical Testing Machine and Video Extension. The tensile strength was between 250-1000MPa, and the modulus was between 17-65GPa. The vascular bundle fracture was brittle fracture; there was no obvious yield point and plastic deformation. The failure mode was divided into two, fist was jagged tear, and the fracture was uneven, with high and low. While The second was more flush stepped fracture.Bamboo vascular bundles was simplified as fiber phase and porous phase, and reached the basic mechanical properties of both. While the experiments show that the consequents were basically consistent with the theoretical. There was a linear relationship between elastic modulus and tensile strength, and the tensile strength increased with the elastic modulus increase. Simultaneously, Fiber content has a significant effect to elastic modulus and tensile strength of vascular bundles. There also have very good linear relationship between fiber content and tensile behavior. With the increasing of fiber content, both elastic modulus and tensile strength were increased.This paper studied the tensile properties of bamboo vascular bundles to determine the vascular tensile mechanical behavior and factors, and then to establish the links between bamboo fibers and vascular bundles, as well as the links of macro-performance and vascular bundles. Futher to establish the links between micro and macro properties of moso bamboo.