Process Zone Length and Fracture Energy of Spruce Wood in Mode-I from Size Effect
Process Zone Length and Fracture Energy of Spruce Wood in Mode-I from Size Effect
复制标题
从尺寸效应看模式一云杉木材的加工区长度和断裂能
作者：
S. Aicher
本文报道了基于 Bazant 尺寸效应定律，在垂直于纤维方向的张力加载下欧洲云杉木材 I 型断裂中断裂能和断裂过程区长度的测定。在尺寸效应模型中，断裂能和断裂过程区长度是相关的，并且代表大型结构或样本的明确极限值。模型参数源自对比例范围为 1:32 的特定单边缺口梁样本的早期实验尺寸效应研究。根据尺寸效应定律得出的 I 型断裂能范围为 250-290 N/m，与基于外部功完成样本破坏的相同样本获得的断裂能一致。标称裂纹尖端之前完全发育的断裂过程区的弹性等效长度被确定在约2mm的范围内。上述相关断裂能的独立证明证实了断裂过程区导出尺寸的有效性。此外，获得的断裂过程区域尺寸与加拿大东部云杉之前基于扫描电子显微镜的结果非常一致。
This article reports on the determination of fracture energy and fracture process zone length in Mode I fracture of European spruce wood loaded in tension perpendicular to the fiber direction based on Bazant's size effect law. Within the size effect model, fracture energy and fracture process zone length are correlated and represent unambiguous limit values for large structures or specimens. The model parameters were derived from an earlier experimental size effect study on specific single-edge notched beam specimens with a scale range of 1:32. The Mode I fracture energy range of 250-290 N/m, derived from the size effect law, is in agreement with fracture energies obtained for the same specimens based on external work to complete specimen failure. The elastically equivalent length of the fully developed fracture process zone ahead of the nominal crack tip was determined to be in the range of about 2 mm. The stated independent proof of the correlated fracture energy confirms the validity of the derived size of the fracture process zone. Furthermore, fracture process zone size obtained is in close agreement with a previous result for eastern Canadian spruce, a finding based on scanning electron microscopy.