Issue 48

A. Takahashi et alii, Frattura ed Integrità Strutturale, 48 (2018) 473-480; DOI: 10.3221/IGF-ESIS.48.45 477 determined by Ando et al. almost coincides with the boundary between the pattern C and D obtained by the s-FEM simulations. The results suggest that the strength of interaction between the non-coplanar embedded cracks is similar to that between non-coplanar surface cracks. Therefore, the alignment rule given by JSME can still give a conservative evaluation of not only surface cracks and also embedded cracks. (a) H=2.5 mm (b) H=5.0 mm (c) H=7.5 mm Figure 4 : Fatigue crack growth behavior of two non-coplanar embedded cracks. The horizontal separation S of the initial crack tips is 10 mm, and the vertical height H is (a) 2.5 mm, (b) 5.0 mm and (c) 7.5 mm. Only crack shape is displayed. The red line shows the crack tip. The top figure is the top view of the crack shape, and the bottom figure is the front view of the crack shape. The crack growth behavior is categorized into (a) pattern B, (b) pattern C, and (c) pattern D, respectively. Figure 5 : Interaction map of two non-coplanar embedded cracks obtained by the s-FEM simulations. The marks shows the fatigue crack growth patterns. The borders determined by the JSME and Ando et al. are also plotted.