Probabilistic Design Tool for Small Turbine Engine High Cycle Fatigue (HCF) Life

"This project will significantly improve the accuracy of small turbine engine high cycle fatigue (HCF) life predictions by including the phenomenon of bladed disk mistuning in the structural analysis modeling. This will be done by developing reduced-ordermodels and integrating them into a probabilistic structural analysis computer code. The reduced-order modeling technique enables a sufficiently accurate representation of the underlying physics while avoiding the prohibitively long computational timesrequired by direct simulations involving random variables. The Phase I Option will develop models and methodologies to predict the redistribution of residual stresses induced by surface enhancement processes (SEP) under thermal and probabilistic HCFloading conditions and use these models to modify the HCF life prediction tool. Phase II would develop the probabilistic model into a robust computational tool and perform verification testing with real data from a limited number of existingturboshaft/turboprop engine bladed disk assemblies. Phase III would generalize the methodology and computer code to a wide variety of gas turbine engine components and applications. The traditional life prediction methodologies used in current smallturbine engine design processes are seriously compromised by their inability to capture the inherently random behavior characteristics of bladed disk assemblies due to mistuning. Consequently, either the compre