The effect of axial scratches on the ductile creep rupture of internally pressurized thin-walled tubes

Ductile creep rupture of internally pressurized thin-walled tubes with a uniform temperature usually occurs at a geometric defect. A model was thus developed to determine how the depth of axial scratches affects the time-to-failure and tangential creep strain at failure of internally pressurized thin-walled tubes. The model was tested using Zircaloy-4 fuel cladding containing machined scratches, and the experimental results agreed reasonably well with the model. The model is sufficiently general that it can also be used to predict the local tangential creep strain at which failure occurs in tubes for which the creep deformation varies around the tube. (author)