摘要
通过理论与试验分析相结合的方法,建立木材多尺度力学分析模型,分析木材的宏观力学性质和断裂机理。在假设木材是含裂纹的各向异性材料基础上,建立了断裂力学分析模型,并用该模型研究了含边缘Ⅰ型裂纹的有限大板的应力场和应力强度因子;进一步分析了木板紧凑拉伸时裂纹的几何特征对应力强度因子的影响,建立了应力强度因子的无量纲关系式;结合模型试验,得到木材的横纹断裂韧性和顺纹断裂韧性参数。结果表明:裂纹的存在对其附近应力场的影响很大,在张应力情况下容易引起木材的断裂,而且顺纹断裂韧性与横纹断裂韧性的差别很大。
Our study analyzed the macro-mechanical properties and fracture mechanism of wood and established the multi-scale mechanical analysis model of wood,both theoretically and empirically.Based on the hypothesis that wood is a kind of anisotropic material including cracks,analysis model of fracture mechanism for wood was established.The stress field and stress intensity factors of finite plates with cracks of edge type I were studied by the model.The effects of geometric features of cracks on the stress intensity factors were further analyzed when a wooden board was used to carry out a compact tension test.The formula for the stress intensity factors was established by dimensional analysis.The toughness factors of transverse fracture and fracture parallel to the grain of wood were further obtained by a model experiment.The results indicate that：1） cracks in wood have a great effect on the stress field;2） in tensile stress,it is easy to induce wood fracture and 3） there is a significant difference between transverse and parallel fracture toughness.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2010年第2期153-156,共4页
Journal of Beijing Forestry University
基金
"973"国家重点基础研究发展计划项目(2009CB724607)
山东省自然科学基金面上项目(Y2007F53)
