落叶松锯屑在木粉加工过程中的断裂分析  

Fracture analysis of larch softwood sawdust in the wood flour processing

作　　者：范长胜[1] 杨冬霞[1,2] 杨春梅[1] 张宏[1,3] 

机构地区：[1]东北林业大学机电工程学院,黑龙江哈尔滨150040 [2]哈尔滨学院工学院,黑龙江哈尔滨150086 [3]塔里木大学机械电气化工程学院,新疆阿拉尔843300

出　　处：《南京林业大学学报（自然科学版）》2013年第6期127-131,共5页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：国家自然科学基金项目(31070500;31170517;31160196);黑龙江省教育厅科学技术研究项目(12533043);中央高校基本科研业务费专项资金项目(DL12C B05)

摘　　要：以干燥后的落叶松锯屑为研究对象,在落叶松锯屑被加工成木粉的过程中,用显微镜分析了不同粒径锯屑颗粒的断裂形态和大小。试验结果表明:粒径为0.08 mm木粉形态主要呈棒状,放大40倍后可见管胞径壁上的纹孔和任意排列的纤丝;颗粒内裂纹的产生和扩展是引起锯屑颗粒断裂的主要原因。基于干燥后的锯屑为脆性板层材料的基本假设,运用断裂力学理论,结合试验分析结果,研究了锯屑断裂过程中木粉颗粒内裂纹间的相互作用机理,得到了适用于锯屑颗粒的断裂判据。The fracture criterion of wood flour is proposed based on the experimental and theoretical results from the dried larch sawdust. The fracture morphology and size of the different mesh sawdust were observed by the microscope in the preparing process of the dried larch sawdust into wood flour. The experimental result shows that the 0. 08 mm wood flour mostly is in the form of sticks and includes the pits and arbitrarily arranged filaments on the radial wall of the tra- cheid observed clearly after enlarged 40 times. The experimental phenomenon presents that the main reason resulting in the fracture of the sawdust grain is the initiation and propagation of the crack in the sawdust grain. The interactive mech- anism between cracks in the sawdust grain during the fracture process of sawdust was investigated by using the theory of fracture mechanics and the experiment results. The fracture criterion of the sawdust grain was obtained based on the in- teractive mechanism and a fundamental assumption that the dried sawdust is the brittle plate laver material.

关 键 词：落叶松锯屑 木粉 断裂分析 

分 类 号：S781[农业科学—木材科学与技术]