Abstract
One of the manifestations of fatigue damage in pressurized components is the development of a crack for which the engineering assessment requires consideration of critical conditions leading to loss of functionality, especially in extreme low probability events under credible accident conditions. This assessment, especially for ductile, tough metals, has been based on the net section collapse (NSC) criterion. The typical inputs used in validating and in applying the criterion have associated uncertainties that can have considerable influence on the resulting or related assessment. The objective of this paper is to provide a formulation for this assessment to enable uncertainty quantification and sensitivity analysis for the NSC validation and application for pipes under pressure and section bending loads. The formulation is developed along the similar approach presented in recent PVP conference papers dealing with the CUF-based fatigue evaluation. The method of analysis is applied to several pipe tests over a wide range of geometries and loadings, and the results are compared with data with the objective of assessing the validity of the NSC criterion. The resulting range of expected uncertainty in the application of the NSC criterion and the ranking of controlling inputs based on the sensitivity analysis are discussed.
