Issue 70

O. Neimark et alii, Frattura ed Integrità Strutturale, 70 (2024) 272-285; DOI: 10.3221/IGF-ESIS.70.16

 H r

2 (1/2)

  

C r

z x r z x

( ) ( (

) ( ))

(20)

x

The log-log plot log 2 C(r) ~log 2 (r) allowed the estimation of the roughness exponent as a spatial invariant corresponding to a constant slope in corresponding range of scales [l sc , L pz ] , (Fig.8).

Figure 6: Fracture surface image (electronic microscopy) of the R5 steel reflecting the crack advance staging: 1 - area of small crack growth, 2 – area of long crack growth, 3 – area of initial crack.

Figure 7: Schematic image of the process zone at the crack tip and typical image of the surface roughness.

(a) (b) Figure 8: a) The surface roughness profile, b) the log 2 C(r) vs log 2 (r) plot.

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