Strain-controlled low cycle fatigue behavior of a superalloy applied in
combustion liner considering the effect of temperature and stress
concentration
Abstract
This study aims to investigate the low cycle fatigue (LCF) behavior and
fatigue life prediction method of an advanced solid solution
strengthened nickel-based superalloy at various temperatures and stress
concentrations. Cylindrical specimens as well as plates with three types
of holes (including straight holes and inclined holes with different
orientations) were designed and machined for fatigue tests. The test
results revealed fatigue life decreases with the temperature increasing.
Meanwhile, the fatigue lives of the plate specimens have decreased
differently and are strongly dependent on the geometry and orientation
of the holes. The key damage parameter related to the fatigue life was
found on the strain gradient path. A criterion based on strain gradient
is defined as the boundary of the damage process zone. The results show
that the prediction was in good agreement with the experimental data,
for the majority of the data is within a scatter band of ±2.