41st Structures, Structural Dynamics, and Materials Conference and Exhibit · 2000 · 25 citations · 4 references
EngineeringLife PredictionMechanical EngineeringSystem ReliabilityDeterioration ModelingReliability EngineeringDesign AssessmentUncertainty QuantificationDynamic ReliabilitySystems EngineeringModeling And SimulationReliability AnalysisStatisticsService Life PredictionReliabilityDarwin Computer ProgramDesignStructural Health MonitoringReliability PredictionHigh Energy RotorsDesign For ReliabilityManufacturing AnomaliesReliability ModellingSoftware TestingFailure Prediction
Conventional rotor life prediction methodologies are based on nominal conditions that do not account for material and manufacturing anomalies that can degrade the structural integrity of high energy rotors. In order to account for these anomalies, an industry committee recommended adoption of a probabilistic damage tolerance approach to supplement the current safe life methodology. The DARWIN computer program computes the probability-of-fracture as a function of flight cycles, considering random defect occurrence and location, random inspection schedules, and several other random variables. This study focuses on the probabilistic fatigue analysis methodology developed and implemented in DARWIN Version 3.2. The computational efficiency and accuracy of this computer program is illustrated for several realistic rotor models provided by aircraft engine manufacturers. It is shown that the life approximation function (LAF) and importance sampling (IS) methods significantly reduce computation time (nearly two orders of magnitude) compared to the Monte Carlo method.
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