Analysis of Creep-Induced Strains and Stresses in the V Notches Process Zone from the CANDU Pressure Tubes

The paper objective was to study the phenomenon of the mechanical stress relaxation in the vicinity of a V notch (blunt flaw) on the inner surface of the CANDU pressure tube. This kind of notches model the Debris Fretting Flaws found by in-service inspection on the fuel channels. The analyses are done inside of a small zone around the flaw, which is called "the process zone". The Neuber's total strain energy density rule is applied to obtain the stress relaxation and the total strain due to the creep phenomenon in the process zone. Further, the paper describes the formalism to obtain the numerical solutions for the stress-strain field in the process zone, where the high stresses are developed due to the flaw tip that play the stress intensifier under tensile stress. (author).