Issue 49

H. Berrekia et alii, Frattura ed Integrità Strutturale, 49 (2019) 643-654; DOI: 10.3221/IGF-ESIS.49.58 645 Figure 1 : Pipe with elliptic defect. Figure 2 : Pipe with rectangular defect. Figure 3 : Model with mesh. Using the programmable language ANSYS [7], a subroutine was developed and implemented in the main code for the determination of critical point (M*) in the zone of corrosion defect (see figure 4) where microcracks may grow [8]. Next, the constitutive law of the critical point (M*) where the equivalents stress σ* is maximum, obtained using the ANSYS code [7], and is implanted in the post- processor based on the Newton iterative method [9]. The study was conducted on pipes of external diameter of 40 '' and a thickness of 12.7 mm in steel X65 whose mechanical properties are grouped in the table 1 [10].