Dynamic fatigue behaviour of Poco and RC4 graphites and a general fatigue design criterion

The dynamic fatigue behaviour of Poco graphite in biaxial loading and 3-point bending has been determined and compared. A comparison of these results with previously published fatigue data for RC4 graphite beams loaded in 4-point bending is also presented. These comparisons indicate that, for practical purposes, one relationship between applied homologous fatigue stress, {sigma}{sub H}, and fatigue life, N, describes the behaviour of both graphites in all modes of loading. (auth)