Issue34

M. Goto et alii, Frattura ed Integrità Strutturale, 34 (2015) 427-436; DOI: 10.3221/IGF-ESIS.34.48 431 Figure 5 : Crack paths at  a = 90 MPa: ( a and c ) sectioning position described in the crack paths of the zx - and xy -planes; ( b and d ) crack paths in the sectioned plane for the zx - and xy -plane cracks. Fig. 6 shows the profile of the crack face, y / l or z / l versus t / l relationship. Dashed lines in Fig. 6a are the crack face profile at  a = 240 MPa represented in terms of T / L , where, l and L are the crack length measured along the circumferential direction at the specimen surface, and along the crack path direction, respectively, and t and T are the crack depth measured along the vertical direction to the specimen surface, and along the crack face direction, respectively (Figs. 7a and 7b). Here, for the xy -plane crack, the flat crack face/path illustrated in Fig. 7b was assumed, whereas the actual path was slightly curved, especially in the initial growth stage. The values of t / l and T / L at the deepest point were Figure 6 : Profile of the crack face in terms of dimensionless sizes: (a)  a = 240 MPa; (b)  a = 90 MPa. Figure 7 : Definition of the crack length/depth for inclined cracks: (a) the zx -plane crack; (b) the xy -plane crack.