Understanding Materials Uncertainty for Prognosis of Advanced Turbine Engine Materials

Larsen, J. M.; Caton, M. J.; Rosenberger, A. H.; John, Reji; Jira, Jay R.; Golden, Patrick J.; Jha, S. K.; Buchanan, Dennis J.

doi:10.2514/6.2010-2973

Cited by 4 publications

(3 citation statements)

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“…Using comprehensive engine performance and stress analysis models of the engine, one can then calculate location-specific stresses and temperatures in individual engine components for use in life analysis. In the longer term, it should be possible to use diagnostics of structural and materials health as part of a comprehensive philosophy of condition based management + prognosis (CBM+) [5][6][7][8][9]. In the longer term, a key goal is to pursue the concept of aircraft digital twin to represent the evolving health state of each individual asset [10].…”

Section: A Bright Future For Materials Designmentioning

confidence: 99%

“…2. This separation in fatigue lifetimes, known as bimodal or competing-modes fatigue, has been observed in a wide range of alloys, including the superalloys: Rene'95 [21,22], Rene'88DT [23], IN100 [8,[24][25][26][27][28][29], Waspaloy [30], the single crystal alloy PWA 1484 [31], the titanium alloys Ti-10-2-3 [23,[32][33][34], Ti-6Al-2Sn-4Zr-6Mo [35][36][37][38][39][40][41][42], Ti-6Al-4V [43][44][45][46][47], gamma titanium aluminides [48,49], the aluminum alloy 7075-T651 [50], and others. Although such a separation of fatigue response has been known for some time [51], the significance of this behavior has not yet been generally captured in the strategies for fatigue design of turbine engine materials.…”

Section: Life Limits and Competing-mode Of Fatiguementioning

confidence: 99%

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Reducing uncertainty in fatigue life limits of turbine engine alloys

Larsen

Jha

Szczepanski

et al. 2013

International Journal of Fatigue

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a b s t r a c tIn probabilistic design of materials for fracture-critical components in modern military turbine engines, a typical maximum design target risk (DTR) is 5 Â 10 À8 component failures/engine flight hour. This metric underscores the essential role of safety in a design process that simultaneously strives to achieve performance, efficiency, reliability, and affordability throughout the life cycle of the engine. Traditionally, the design and life management approaches for engine materials have typically relied on extensive testing programs to produce large databases of fatigue data, from which statistically based life limits are derived by extrapolation from the mean fatigue behavior. However, we have found that the statistical behavior of fatigue lifetimes under a given test condition often exhibits a bimodal form, and that the trends in mean vs. minimum fatigue lifetime typically respond differently to loading or to microstructural variables. Under such circumstances, the underlying life-limiting mechanisms appear to exhibit a probabilistic microstructural hierarchy in fatigue resistance that is controlled by susceptibility of local microstructural neighborhoods to early damage and the growth of small cracks. These findings suggest that significant opportunities may exist for reductions in uncertainty in materials life-cycle prediction and management, if such hierarchies can be understood and controlled. This paper explores the potential implications of these findings, and a number of possible approaches are suggested for incorporating the insights of life-limiting fatigue into methods of integrated computational materials engineering (ICME) to support optimized life-cycle design of materials and components in turbine engines. Benefits of this approach appear to include substantial improvements in model accuracy, coupled with reduced requirements for materials testing, potentially leading to a significant reduction in the time and cost to develop, validate, transition, and implement new, more fatigue resistant alloys. Published by Elsevier Ltd.

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Section: A Bright Future For Materials Designmentioning

confidence: 99%

Section: Life Limits and Competing-mode Of Fatiguementioning

confidence: 99%

Reducing uncertainty in fatigue life limits of turbine engine alloys

Larsen

Jha

Szczepanski

et al. 2013

International Journal of Fatigue

View full text Add to dashboard Cite

show abstract

“…When GEA developed the LEAP engine with SiC/SiC CMC shrouds, they made the decision to incorporate these new CMC components based on a safe life approach (Suresh, 1998;Grandt, 2004;Larsen, 2010). The approach employed to introduce the GEA shrouds started with the identification of the key turbine engine operational cycle points that generate the most critical combined stress and temperature points for the shroud.…”

Section: Introductionmentioning

confidence: 99%