Scale effect of material structure on the similarity of subcritical crack growth under sustained loading

Article type: Research Article

Authors: Sugiura, Ryuji^; | Yokobori Jr., A. Toshimitsu | Ohmi, Toshihito | Nagumo, Yoshiko | Matsuzaki, Takashi | Yardley, Victoria A.

Affiliations: Graduate School of Engineering, Tohoku University, Sendai, Japan

Note: [] Address for correspondence: Ryuji Sugiura, Graduate School of Engineering, Tohoku University, Aoba 6-6-01, Aramaki, Aoba-ku, Sendai 980-8579, Japan. Tel.: +81 22 795 6904; Fax: +81 22 795 6904; E-mail: [email protected]

Abstract: The irregularity of shapes of fractured units with various lengths in a creep crack path on creep crack growth resistance were characterized based on the concept of the fractal and scaling effect. Furthermore, the general validity of this characterization for subcritical crack growth was proposed by comparing the obtained results with those in rock fracture. As a result, both the fracture unit length denoted as FA of creep cracking in metals and the characteristic scale of rock fracture were found to have fractal dimensions that show both have the same scale effect. These results will promote that the possibility of a unified scientific description of the effect of geometrical morphology of various subcritical crack growth patterns will be possible on the basis of the concept of the fractal and characteristic scale effect.

Keywords: Creep, crack propagation, EBSD, scale fracture, strengthening mechanism

DOI: 10.3233/SFC-2012-0147

Journal: Strength, Fracture and Complexity, vol. 7, no. 4, pp. 321-332, 2012