Fracture Mechanics Consideration of Residual Stresses Introduced by Coldworking Fastener Holes

Abstract

Aluminum test specimens are prepared with precracked fastener holes, coldworked by means of an oversized mandrel, and then cycled to failure under constant amplitude loading. A simplified fracture mechanics analysis is performed to predict the fatigue crack growth life caused by the coldworking process. As discussed here, the analysis method is capable of obtaining reasonable estimates for the test specimen fatigue life and of determining the maximum crack size which can be “permanently” arrested by the coldworking process.