摘要
木材材料的各向异性导致木材断裂裂纹具有强烈的非均质性,其在二维空间内的分布具有非线性特征。运用数盒子法对裂纹发育带在二维平面内的分布进行了分形特征研究,发现木材裂纹具有明显的分形规律,分形维数为1.2～1.5;通过比较不同时间段的裂纹发育情况,发现裂纹的分形维数随着裂纹的扩展呈增加的趋势。对木材断裂过程的应力场进行分形研究的结果表明,裂纹应力场也表现出分形的特征,并且分形维数在裂纹尖端处最小,在远离裂纹尖端处较大。
Wood cracks in an irregular path due to its anisotropic nature. This property also leads to the non-linear distribution of the crack in the two dimensions. The crack and stress-strain of Chinese White Poplar (Populus tomentosa) was studied by the box counting method. The results showed that the cracks were obvious fractal and that the value of dimension D was determined to be betw een 1.2 ～ 1.5 by studying the crack propagation in the two dimensions. By comparing the crack propagation over a period of time, we found that the value of D increased as the crack increased. The stress field of the crack revealed the fractal property and the value of D was found to be smaller at the tip of the cra ck and increased as the distance from the tip of the crack increased.
出处
《木材工业》
2003年第3期7-9,12,共4页
China Wood Industry
基金
国家自然科学基金资助项目(30170748)。
