The consideration of realistic load assumptions is important for the
fatigue design of highly stressed nodular cast iron components for wind
energy application. Especially in case of overloads causing
elastic-plastic deformation, residual stresses may have a strong impact
on fatigue life. In strain-controlled fatigue tests with constant and
variable amplitudes, the influence of overloads on the lifetime was
investigated. The overload was applied with the objective to create high
tensile residual stresses. During fatigue testing the transient material
behavior, cyclic hardening, cyclic relaxation of the residual stresses
as well as quasi static creep effects, of the EN-GJS-400-18-LT was
recorded and evaluated. To quantify the influence of the transient
material behavior on the calculated lifetime, fatigue analyses are
carried out with the strain-life approach, both with and without
consideration of the transient material behavior. The results show that
conservative damage sums are derived if the transient material behavior,
especially the relaxation of tensile residual stresses, is neglected.