A Web-Based Uncertainty Plug-In (WUPI) for Fatigue Life Prediction Based on NDE Data and Fracture Mechanics Analysis

Over the last thirty years, much research has been done on the development and application of failure event databases, NDE databases, and material property databases for pressure vessels and piping, as reported in two recent symposia: (1) ASME 2007 PVP Symposium (in honor of the late Dr. Spencer Bush), San Antonio, Texas, on “Engineering Safety, Applied Mechanics, and Nondestructive Evaluation (NDE).” (2) ASME 2008 PVP Symposium, Chicago, Illinois, on “Failure Prevention via Robust Design and Continuous NDE Monitoring.” The two symposia concluded that those three types of databases, if properly documented and maintained on a worldwide basis, could hold the key to the continued safe and reliable operation of numerous aging nuclear power or petrochemical processing plants. During the 2008 symposium, four uncertainty categories associated with causing uncertainty in fatigue life estimates were identified, namely, (1) Uncertainty-1 in failure event databases, (2) Uncertainty-2 in NDE databases, (3) Uncertainty-3 in material property databases, and (4) Uncertainty-M in crack-growth and damage modeling. In this paper, which is one of a series of four to address all those four uncertainty categories, we address Uncertainty-2 in NDE databases by developing a Web-based Uncertainty Plug-In (WUPI), which automates the uncertainty estimation algorithms of flaw sizing, fracture toughness, and crack growth vs. ΔK data such that NDE data from the field can be acted on by office engineers with a reduced feedback time for maintenance decision making.