Quantification of low-cycle fatigue damage accumulation in stress concentration area by local strain evolution

Abstract

The novel non-destructive method for quantitative description of low-cycle fatigue damage accumulation is proposed and implemented. The key point, that defines scientific novelty and powerfulness of this approach, consists of involving various deformation parameters referred to critical point belonging to the hole boundary as current damage indicator. Required strain values follow from distributions of all three displacement components along the hole edge measured by reflection hologram interferometry. The derived data at different stage of low-cycle fatigue lead to normalized dependencies of various strain parameters from number of loading cycle, which are a source of damage accumulation functions.