ABSTRACT
SUMMARY Fatigue tests conducted in the laboratory have traditionally been performed using loads which vary sinusoidally with time at a constant amplitude. Loads carried by a structure in service also vary with time, but amplitudes of load cycles generally are not constant. To estimate the service life of a structure, an engineer must convert the variable-amplitude service loads to a form compatible with experimental data. In this chapter, methods are described for assessing, on the basis of constant-amplitude data, fatigue damage caused by variable amplitude load-time histories.
