Issue 48

A. Takahashi et alii, Frattura ed Integrità Strutturale, 48 (2018) 473-480; DOI: 10.3221/IGF-ESIS.48.45 475 the criteria proposed by Richard et al. [10]. The positions of crack tip segments are updated in accordance with the calculated crack growth amount and direction. Figure 1 : A schematics of the s-FEM. The geometry and boundary conditions are modeled with global mesh. The cracks are modeled with local meshes separately from the global mesh. The local meshes are superimposed on the global mesh to obtain the displacement solution of the problem. Figure 2 : Finite element mesh for the fatigue crack growth simulation of two non-coplanar embedded cracks. Each cracks is modelled with each local mesh separately. The position of the center of two cracks are at 100 mm distance from the surface of the specimen. The horizontal separation and vertical height of the crack tips are denoted by H and S . The maximum tensile stress is 127 MPa, and the stress ratio R is 0.1. The displacement at the bottom surface is fully constraint. F ATIGUE CRACK GROWTH SIMULATION OF TWO NON - COPLANAR EMBEDDED CRACKS n this paper, we focus on the validity and reliability of the alignment rule in the FFS code, the fatigue crack growth behavior of two non-coplanar embedded cracks are simulated. Fig. 2 shows the finite element model of the fatigue crack growth simulation of two non-coplanar embedded cracks. Two circular embedded cracks are embedded in a rectangular shape of specimen. The size of the rectangular specimen in x, y and z direction are 750 mm, 250 mm and 200 mm, respectively. The center of two cracks are located at 100 mm distance from the surface of the specimen, and the cracks I