Turbine Fatigue Reliability and Life Assessment Using Ultrasonic Inspection: Data Acquisition, Interpretation, and Probabilistic Modeling
A general method and procedure of fatigue reliability and life assessment of steam turbines using ultrasonic inspections is presented in this chapter. The basic structure of an automated ultrasonic inspection system using in turbine surface engineering is briefly introduced. Using the inspection information, a probabilistic model is developed to quantify uncertainties from flaw sizing and model parameters. The uncertainty from flaw sizing is described using a probability of detection model which is based on a classical log-linear model coupling the actual flaw size with the ultrasonic inspection reported size. The uncertainty from model parameters is characterized using Bayesian parameter estimation from fatigue testing data. A steam turbine rotor example with realistic ultrasonic inspection data is presented to demonstrate the overall method. Calculations and interpretations of assessment results based on risk recommendations for industrial applications are also discussed.
KeywordsMonte Carlo Nuclear Regulatory Commission Ultrasonic Inspection Indication Point Fatigue Reliability
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