Mechanical relaxation of localized residual stresses associated with foreign object damage

Foreign-object damage associated with the ingestion of debris into aircraft turbine engines can lead to a marked degradation in the high-cycle fatigue life of turbine components. This degradation is generally considered to be associated with the premature initiation of fatigue cracks at or near the damage sites; this is suspected to be due to, at least in part, the impact-induced residual stress state, which can be strongly tensile in these locations.