Issue 33

M. Mokhtari et alii, Frattura ed Integrità Strutturale, 33 (2015) 143-150; DOI: 10.3221/IGF-ESIS.33.18

same estimation of K I . Therefore, in order to obtain a reliable experimental estimation of SIF (accuracy less than 0.5 MPa√m) from displacement data measured by DIC of aluminium 2014-T351 alloy, one can choose the FOV ranging from 8×8 to 20×20 mm 2 with an arbitrary subset size ranging from 19 to 151 pixel for a scratched surface of a fatigue cracked CT specimen.

b

a

d

c

1 term

2 terms

f

e

10 terms

Figure 4. Analysed displacement field, a) vertical displacement, b) horizontal displacement. Fitting of displacement data to Williams’ solution with one (c) , two (d) and 10 terms (e) and stability of calculated SIF and T-stress for the first 20 terms of Williams’ series (f) .

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