PSI - Issue 13

364 H.E. Coules / Procedia Structural Integrity 13 (2018) 361–366 Author name / Structural Integrity Procedia 00 (2018) 000 – 000 and pressurised internally. The tube contains a pair of identical semi-elliptical axial-radial cracks with a depth = 0.5 = 25 , an aspect ratio = 0.5 and a separation distance = 0.25 = 12.5 . The material is A533B Class 1 ferritic steel at ambient temperature, modelled using incremental plasticity theory and isotropic hardening. The strain-hardening curve is approximated closely by a Ramberg-Osgood relationship. 4

a)

b)

d)

c)

e)

f) Figure 3: Stress intensity factor and interaction factor as a function of position on the crack tip line for twin semi-elliptical flaws in a plate subject to two loading conditions; uniform tension and thermal shock. a-c.) Uniform tension. d-f.) thermal shock of a RPV during MLOCA. Note that the interaction factor (c. and f.) varies widely depending on the type of loading.