Probabilistic Turbine Blade Tip Durability Analysis

Mcknight, R. L.; Bechtel, G. S.; Cook, Thomas C.

doi:10.2514/6.1993-1383

Cited by 3 publications

(5 citation statements)

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“…It is vitally important that this nonlinear deformation in both the coating(s) and the substrate be characterized. This was demonstrated in previous studies on coated blades by McKnight, et al (1982), Hillery, et al (1987), Swanson, et al (1987), and Heine, et al (1989). In the work of Hillery, et al (1987), coated specimens underwent pure thermal cycles (21 -871-21C) with a hold at maximum temperature.…”

Section: Introductionsupporting

confidence: 68%

TMFSLAM-Design Analysis Tool for Coated Structures

Bechtel

Mcknight

Cook

1991

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation;

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Hot flowpath components in aircraft gas turbine engines are subject to a severe operating environment. The large thermal gradients can produce high thermal strains which, when combined with mechanical loads and a deleterious environment, can lead to premature failure. To combat this possibility, designers spend considerable time determining the stress and strain fields in these components as the parts undergo typical operating histories. These field quantities can then be used to determine failure parameters and determine life limiting locations. The field determinations can be difficult and, in combination with numerous potential failure mechanisms, the structural assurance process can take a considerable time to complete. To shorten this process, a personal computer (PC) based preliminary design system has been developed. This system, called Thermomechanical Fatigue – Structural Life Assessment Method (TMFSLAM), permits the user to rapidly evaluate the interactive effects of duty cycle, geometry, and materials on component life. The quantitative results determined by TMFSLAM will be available to make decisions on design changes, material substitution, etc.

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Section: Introductionsupporting

confidence: 68%

TMFSLAM-Design Analysis Tool for Coated Structures

Bechtel

Mcknight

Cook

1991

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation;

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“…These roughness measurements both had a cut-off length of 250 µm. Chemical composition and mechanical properties of René 80 can be found in [5,8,9]. …”

Section: Experimental Plan and Samplesmentioning

confidence: 99%

“…These roughness measurements both had a cut-off length of 250 μm. Chemical composition and mechanical properties of René 80 can be found in [5,8,9]. As a consequence, contact area and pressure calculated using Hertz's theory at different temperatures are listed in Table 1.…”

Section: Experimental Plan and Samplesmentioning

confidence: 99%

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Contact Properties and Wear Behaviour of Nickel Based Superalloy René 80

Lavella

2016

Metals

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A superalloy traditionally offers excellent mechanical strength, resistance to thermal creep deformation, good surface stability and resistance to corrosion or oxidation. However, a superalloy often also needs performance in terms of fretting resistance. Experimental results regarding fretting wear and contact properties of the superalloy René 80 are illustrated and discussed. The widespread applications of superalloys in jointing with friction as in the jointing of a turbine blade, is the main motivation for characterizing their fretting behaviour. The fretting experiments were performed at 100 Hz for two temperatures (600, 800˝C), and two sliding amplitudes (30, 60 µm). These temperatures and strokes are typical at the medium stage of a low-pressure gas turbine. Wear volume and the contact properties such as friction coefficient and tangential contact stiffness were measured and analysed. Results show that the lowest friction coefficient was measured at the temperature of 800˝C. This temperature hence appears to be an optimum working condition for the fretting wear of René 80. With regard to wear mechanism, a fundamental role of the sliding amplitude was found. In particular, the ratio between the sliding amplitude and the characteristic contact length has a significant influence upon the oxide growth on contact surfaces.

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“…Nevertheless, these past two decades have given the viscoplastic community a vast wealth of experience with a variety of evolution equations that need to be verified and implemented through characterization of models that have predictive capabilities that are in reasonable agreement with experiments [11]. Moreover, analytical studies of engine hot section components, such as turbine blades [12] and combustor liners [13], have demonstrated that classical methods do not always accurately predict the cyclic response of a structure, simply because of the lack of interaction between plasticity and creep. In addition to the inability to model the interaction between creep and plasticity, most of the classical plasticity theories suffer from an inability to model material behavior under cyclic loading conditions.…”

Section: Freed's Viscoplastic Modelmentioning

confidence: 99%

Characterization of a Viscoplastic Constitutive Model and Its Application for the Finite Element Analyses of a Stirling Space Power Converter Heater Head

Abdul-Aziz

Krause

Tong

2003

Mechanics of Advanced Materials and Structures

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NASA has identified the Stirling power converter as a prime candidate for the next generation power system for space applications requiring 60,000 hours of operation. To meet this long-term goal, several critical components of the power converter were analyzed using advanced structural assessment methods. Perhaps the most critical component, because of its geometric complexity and operating environment, was the power converter's heater head. Low-cycle fatigue and creep experiments on a nickelbase superalloy, Udimet 720 LI (low inclusions) and viscoplastic analyses for the Stirling starfish heater head were conducted. All testing was performed at temperatures of 625 to 820• C in air. This work was initiated to generate a unique and consistent database in support of a life prediction modeling effort aimed at characterizing Freed's viscoplastic model and verifying the key damage mechanisms. In general, this paper describes the life assessment of the heater head, which included the characterization of a viscoplastic material model, the thermal and structural analyses of the heater head, and the interpolation of fatigue and creep test results at several elevated temperatures for life prediction purposes.

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Probabilistic Turbine Blade Tip Durability Analysis

Cited by 3 publications

References 1 publication

TMFSLAM-Design Analysis Tool for Coated Structures

TMFSLAM-Design Analysis Tool for Coated Structures

Contact Properties and Wear Behaviour of Nickel Based Superalloy René 80

Characterization of a Viscoplastic Constitutive Model and Its Application for the Finite Element Analyses of a Stirling Space Power Converter Heater Head

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