Elastic-plastic FEM-analysis of a nozzle corner crack and discussion of the results by some fracture mechanics concepts

Abstract This paper presents the results of an elastic-plastic threedimensional finite element analysis for a nozzle corner crack in a pressurized reactor test vessel. The calculations were performed by the finite element program ADINA incorporating von Mises' yield condition and isotropic hardening. The crack plane was taken parallel to the axis of the vessel and the crack front straight and perpendicular to the symmetry line of the nozzle corner in order to obtain the worst position for a nozzle corner crack. The calculations were performed up to that pressure level where general yield of the ligament in the nozzle corner section takes place. The results of the finite element analysis are compared with figures obtained from analytical procedures of elastic-plastic fracture mechanics.