PSI - Issue 60

P.A. Jadhav et al. / Procedia Structural Integrity 60 (2024) 631–654 P.A. Jadhav et. al./ Structural Integrity Procedia 00 (2019) 000 – 000

645 15

1.E-13 1.E-12 1.E-11 1.E-10 1.E-09 1.E-08 1.E-07 1.E-06 1.E-05

2c = 1.5 2c = 2.875 2c = 5

_

0

5

10

15

20

a/t (%)

Fig. 9. The plot of _ with respect to the mean value of flaw depth. ( = 10 microns, = 0 MPa, = 35 ppm)

1.E-03

1.E-04

1.E-05

1.E-06

2c = 1.5 2c = 2.875 2c = 5

1.E-07

_

1.E-08

1.E-09

1.E-10

0

5

10

15

20

a/t (%)

Figure 10: The plot of probability of leak and break with respect to the mean value of flaw depth. ( = 50 microns, = 0 MPa, = 35 ppm) The effect of flaw root radius on the value of _ is shown in Fig. 11. It is not possible to measure the root radius by conventional non-destructive testing methods, it is typically measured in a plant by employing the replica method describes in IAEA-TECDOC-1037 (1998). The assessment of root radius is very challenging and scatter in the data so obtained, cannot be ruled out. The value of _ is a strong function of the root radius as seen in Fig. 11. The value of _ is higher for the lower root radius. The lower root radius gives higher stress concentration factor leading to higher chances of DHC initiation.