The measurement of mechanical properties of cladding tubes by ring samples

The stress-strain curve for reference and irradiated Zr-tube material has been evaluated from measured force-deflection curves using circular tube ring samples. The yield stress has been measured by small force ring compressions and the tensile stress in a tensile loading mode. The strain values were measured directly from the ring surface with a microscope. The strain values were also calculated from the measured spring constants of rings which were loaded to the maximum force. The main emphasis of this report is on the measuring technique. (author)