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

644 14

Limit state for the break before leak is given by eq. 16. 2 = max( 1 , − 2 )

(16)

Fig. 8 gives the _ as a function of crack depth. As expected _ is higher for greater values of crack depths and lengths. It is observed that the probability estimates increase at a higher rate on increasing the flaw depth for smaller depths. This rate reduces for higher crack depths. In Fig. 9, similar cases are plotted with y-axis representing the _ . It can be seen that the _ is significantly less than the _ . This shows that chances of a DHC crack causing a break is significantly lower than it causing a leakage. The effect of flaw root radius on the value of _ is shown in Fig. 10. This figure is similar to Fig. 8 except that the root radius of the flaw considered in this case is 50 microns.

1.E+00

1.E-01

1.E-02

1.E-03

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

1.E-04

_

1.E-05

1.E-06

1.E-07

0

5

10

15

20

a/t (%)

Fig. 8. The plot of _ with respect to the mean value of flaw depth. ( = 10 microns, = 0 MPa, = 35 ppm)