Issue 49

G. Meneghetti et alii, Frattura ed Integrità Strutturale, 49 (2019) 82-96; DOI: 10.3221/IGF-ESIS.49.09

-90

°

h [W/m 2 ]

10 2 10 3 10 4 10 5

-45

-112.5

°

°

°

-67.5

-135

°

°

°

-22.5

-157.5

°

10

0

180

°

°

22.5

157.5

°

°

45

135

°

°

67.5

112.5

°

90

=0.52 mm; a=11.66 mm;  K I,FE

Figure 14 : Specific heat flux distribution measured along the boundary of V c (R c

=35.4 MPa·m 0.5 , f L

=35

Hz).

C RACK PROPAGATION DATA RATIONALIZED IN TERMS OF EXPERIMENTAL J - INTEGRAL

T

he crack propagation data shown in Fig. 8 have been reanalyzed in terms of experimental J-integral in Fig. 15, along with the mean curve, the 10-90% survival probability scatter band and the scatter index T da/dN . Considering that the fatigue tests were carried out by imposing a load ratio equal to -1 (R=-1), the  J was assumed equal to J max . The crack growth rates were synthesized in terms of  J evaluated by means of FE analyses in Fig. 16. It can be seen that numerical results are very well fitted by the 10-90% survival probability scatter band shown in Fig. 15.

10 -4

AISI 304L R=-1

10 -5

10 -6

10 -7

 J from Eq.(18)

da/dN [m/cycle]

10%

T da/dN

=4.41

90%

10 -8

10 2

10 3

10 4

10 5

10 6

Experimental  J [J/m 2 ]

Figure 15 : Crack propagation rates versus the J-integral range evaluated from temperature measurements.

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