ASSESSING FATIGUE ENDURANCE OF PITTED SPECIMENS BY MEANS OF AN INTEGRATED FRACTURE MECHANICS APPROACH

LARROSA N.L.; CHAPETTI, M.D.; AINSWORTH R.A.

Boston, Massachusetts, USA

Conferencia; ASME 2015 Pressure Vessels & Piping Conference; 2015

ASME

From an operator/engineering perspective, the correct assessment of the severity of corrosion defects (e.g., pits) can have enormous economic, social and environmental benefits; therefore the development of a generally applicable and simple to applyprocedureforfatigueassessmentofkeycomponentsisrecognisedasavaluabletool,seekingtoreducethecurrentoverlyconservative procedures whilst maintaining structural integrity. The critical condition for a crack emanating from a pit (pit-to-crack transition)tostarttopropagateisanalysedinthispaper. Thepitcrack configuration is re-characterized into that of a hemispherical crack of length equal to the pit depth, and this assumption is analysedbydetailed3DFEA.Apropagationthresholdapproach is used to estimate the fatigue resistance from intrinsic material properties. The proposed approach is validated by comparison with experimental results available in the open literature