DIN EN 843-7:2010-11

In this standard, two methods for performing ultimate strength tests on slotted rings (C-rings) are specified in order to determine the strength of ring or tube-shaped components in the manufactured geometry. The diametric stress on a short length of a slotted tube or a slotted ring produces tension in the middle of the tube wall, either in the outer wall area, if the ring is pressed together, or in the inner wall area, if the ring is widened with tensile stress. In both cases, the maximum tensions are in the tube surface; they are located far away from the points of stress attack and are thus only weakly influenced by the geometry of the stress attack. In contrast to this, a diametrical pressure on a ring without slots leads immediately to high tensile stresses which are located in the opposite directions to the points of stress attack, namely with poor calibration and higher sensitivity on the geometry of the stress. The standard has been prepared by Technical Committee CEN/TC 184 "Advanced technical ceramics" the secretariat of which is held by BSI (United Kingdom). The responsible German committee is Working Committee NA 062-02-91 AA "Prüfung von Hochleistungskeramik - Monolithische Werkstoffe" ("Testing of advanced technical ceramics - Monolithic materials") at NMP.