Issue 50

P. Livieri et alii, Frattura ed Integrità Strutturale, 50 (2019) 613-622; DOI: 10.3221/IGF-ESIS.50.52 620 Figure 7 : Example of mesh used in the numerical FE analysis for the evaluation of SIF for point C (the dimensions of smaller elements at the tip of the crack were in the order of 10 -5 mm- a=0.3 mm, d=0.4 mm). a d A I n K  Eqn. (13) C I n K  Eqn. (13) A I n K  FE C I n K  FE [mm] [mm] [mm 0.5 ] [mm 0.5 ] [mm 0.5 ] [mm 0.5 ] 0.3 0.4 1.088 0.795 1.166 0.816 0.1 0.15 0.818 0.583 0.858 0.611 0.1 0.3 0.566 0.488 0.608 0.524 Table 1 : Stress intensity factor at points A and C of Fig. 5 for a nominal tensile loading σ n (opening angle 135°). X Y   0 30 60 90 120 150 180 210 240 270 300 330 1 0.5 0 [deg] Figure 8 : Defects (maximum diameter 0.42 mm) Figure 9 : Defect in dimensionless form obtained by dividing the radius by half the value of the maximum diameter. As an example, the calculation procedure described in the previous section is used to calculate the form factor Y, which refers to a small defect detected inside a metallic material. Fig. 8 reports an irregular defect of a maximum diameter equal to