Issue 49

O. Y. Smetannikov et alii, Frattura ed Integrità Strutturale, 49 (2019) 140-155; DOI: 10.3221/IGF-ESIS.49.16 151 of this type required the development and manufacture of special tooling for securing cylindrical specimens in the grips of testing machine during tensile tests. Tensile tests were carried out at room temperature and at the prescribed speed of grips displacement, which was 0.2 mm/min. a b Figure 9 : Comparison of experimental fractures in specimens and calculated fractures (thin solid lines) (a); the results of digitalization of fracture paths (b): line 1 – experiment; line 2 – experimental average, line 3 – calculation. The stress intensity factor К 1С was calculated by the formulas presented in work [15] for a cylindrical specimen with a surface o-ring fracture subject to tensile stress. 1 2 ( ) Ic P K b f b     ,