Issue 36

Lj. L. Vulićević et alii, Frattura ed Integrità Strutturale, 36 (2016) 46-54; DOI: 10.3221/IGF-ESIS.36.05 53 0 1000 2000 3000 4000 5000 6000 7000 8000 0 20 40 60 80 100 120 step of propagation Keq [MPa mm 1/2 ] Figure 11 : Relationship between equivalent stress intensity factor K eq and propagation step. 1 10 100 1000 10000 0 20 40 60 80 100 120 Step cycles number log N Figure 12 : Obtained relationship between steps and number of cycles. 0 50 100 150 200 250 0 2000 4000 6000 8000 10000 12000 Number of cycles N Crack length a [mm] Figure 13 : Relationship between crack length a and number of cycles N using 3D simulation. C ONCLUSION ased on the presented results, one can conclude that experimental and numerical results agree well, with some differences which require further investigation. Therefore, the obtained stress intensity factor histories can be used to predict fatigue crack growth rates. B