Einflußgrößen für die schwingfeste Bemessung von keramischen Bauteilen aus Al2O3 und Si3N4 im Temperaturbereich zwischen 20 und 1200 Grad Celsius

The investigations carried out and the results presented show clearly that for a fatigue design against cyclic loading the knowledge of conventional properties like tensile or compressive static stresses are not sufficent; they do not contain the information about endurable stresses, the effects of mean-stress and notch sensitivity as well as the size effect obviously reduced under cydic loading. However, if cyclic fatigue properties are not available in dependency of stress-concentration, mean-stresses, and loading mode, a preliminary fatigue design can be carried out by applying the proposed uniform S-N curve. The starting point ist then the monotonic bending strength of the candidate ceramic material (P sub s = 50 %) obtained from specimens having similar dimensions as the component to be designed. But this procedure requires subsequent verification tests with real oomponents.