Design Against Variable Amplitude Fatigue — an approach through Cyclic Stress-Strain Response

ABSTRACT Some of the unsolved problems in variable amplitude fatigue are described, and we present a method of attacking them through cyclic stress-strain response. Thus we review cyclic stress-strain behavior and its structure sensitivity at low amplitudes, taking account of the effects of variable loading. The role of mean stress, and how to handle it in variable amplitude fatigue, is explored, and also the load interaction mechanism on fracture initiation. The method is appropriate to “smooth” specimens and components in which crack propagation kinetics are less important for determining life.