Stress intensity factor calculation for surface and subsurface semielliptical cracks in Dy 500 nozzle zone of WWER-440 reactor pressure vessel

Stress-strained state of the Dy 500 nozzle interface with the WWER-440 vessel in case of the maximum project accident is calculated. Stress intensity factor for semielliptical cracks in the nozzle-vessel zone conjugacy is determined. The above factor was obtained by crack virtual growth method and by asymptotic displacement method. It is shown that stress intensity factors calculated through functions of influence are in fair agreement with those ones estimated by discrete model with the given crack. This testifies to the possibility of using methodology for determining the factors on the basis of influence functions in case of structures having geometrical inhomogeneity.