Abstract
In life assessment of a crack-like defect, treatment of secondary stresses is more important than that of primary stresses in view of practical application to an actual elevated temperature component. However, most of the previous experimental studies have been based on crack propagation tests performed in load-controlled conditions. Thus applicability of fracture mechanics based approach to actual industrial purposes is still uncertain. The author has made some suggestions, based on mostly theoretical and numerical investigations, for crack propagatin life prediction including treatment of realistic secondary stresses. This paper presents an experimental validation of the previously proposed methodologies by performing creep-fatigue crack propagation test of a typical high temperature material, CrMoV forged steel under displacement-controlled loading.
