Probabilistic Methods for Ceramic Component Design and Implications for Standards

Author(s):  
J Cuccio ◽  
A Peralta ◽  
J Song ◽  
P Brehm ◽  
C Johnson ◽  
...  
Author(s):  
Masaru Sakakida ◽  
Tadashi Sasa ◽  
Kazuho Akiyama ◽  
Shinya Tanaka

CGT 301 is a recuperated, single-shaft, ceramic gas turbine for cogeneration capable of continuous full load application. In order to reduce its size, thermal stress, and deformations, ceramic parts are designed axi-symmetrically. The combustor is located on a shaft axis just before the turbine, therefore it does not have a large scroll. The turbine is a two-stage axial flow-type with ceramic blades. For the first phase of the program, the primary-type gas turbine with all-metallic parts was fabricated and tested under various conditions. The test results confirmed the rotation stability of the gas turbine. After the test of preliminary metallic gas turbine, all-ceramic parts were fabricated and various tests were carried out to confirm their reliability. The configuration and structure of the ceramic turbine were improved based on the data obtained from the tests of the primary-type gas turbine and the fundamental tests for ceramic components. The primary-type ceramic gas turbine of TIT 1200°C was designed and fabricated for the second phase of the program. This paper outlines the concept of the ceramic component design, test results of ceramic parts in the hot section, and the engine test.


1987 ◽  
Vol 2 (4) ◽  
pp. 809-812 ◽  
Author(s):  
T. SOMA ◽  
Y. ISHIDA ◽  
M. MATSUI ◽  
I. ODA

1989 ◽  
Vol 111 (1) ◽  
pp. 158-167 ◽  
Author(s):  
G. L. Boyd ◽  
D. M. Kreiner

The Garrett Turbine Engine Company/Ford Advanced Gas Turbine Program, designated AGT101, came to an end in June 1987. During this ceramic technology program, ceramic components were exposed to over 250 h of engine test. The 85-h test of the all-ceramic hot section to 1204C (2200F) was a significant accomplishment. However, this AGT101 test program also identified ceramic technology challenges that require continued development. These technology challenges are the basis for the five-year Advanced Turbine Technology Applications Project (ATTAP), which began in Aug. 1987. The objectives of this program include: (1) further development of analytical tools for ceramic component design utilizing the evolving ceramic material properties data base; (2) establishment of improved processes for fabricating advanced ceramic components; (3) development of improved procedures for testing ceramic components and test verification of design methods; and (4) evaluation of ceramic component reliability and durability in an engine environment. These activities are necessary to demonstrate that structural ceramic technology has the potential for competitive automotive engine life cycle cost and life.


Author(s):  
M. L. Easley ◽  
J. R. Smyth

Under the U.S. Department Of Energy/National Aeronautics and Space Administration (DOE/NASA) funded Ceramic Turbine Engine Demonstration Program, AlliedSignal Engines is addressing the remaining critical concerns slowing the commercialization of structural ceramics in gas turbine engines. These issues include demonstration of ceramic component reliability, readiness of ceramic suppliers to support ceramic production needs, and enhancement of ceramic design methodologies. The AlliedSignal/Garrett Model 331-200[CT] Auxiliary Power Unit (APU) is being used as a ceramics test bed engine. For this program, the APU First-stage turbine blades and nozzles were redesigned using ceramic materials, employing the design methods developed during the earlier DOE/NASA funded Advanced Gas Turbine (AGT) and Advanced Turbine Technologies Application Project (ATTAP) programs. The present program includes ceramic component design, fabrication, and testing, including component bench tests and extended engine endurance testing and field testing. These activities will demonstrate commercial viability of the ceramic turbine application. In addition, manufacturing process scaleup for ceramic components to the minimum level for commercial viability will be demonstrated. Significant progress has been made during the past year. Engine testing evaluating performance with ceramic turbine nozzles has accumulated over 910 hours operation. Ceramic blade component tests were performed to evaluate the effectiveness of vibration dampers and high-temperature strain gages, and ceramic blade strength and impact resistance. Component design technologies produced impact-resistance design guidelines for inserted ceramic axial blades, and advanced the application of thin-film thermocouples and strain gages on ceramic components. Ceramic manufacturing scaleup activities were conducted by two ceramics vendors, Norton Advanced Ceramics (East Granby, CT) and AlliedSignal Ceramic Components (Torrance, CA). Following the decision of Norton Advanced Ceramics to leave the program, a subcontract was initiated with the Kyocera Industrial Ceramics Company Advanced Ceramics Technology Center (Vancouver, WA). The manufacturing scaleup program emphasizes improvement of process yields and increased production rates. Work summarized in this paper was funded by the U.S. Dept. Of Energy (DOE) Office of Transportation Technologies, part of the Turbine Engine Technologies Program, and administered by the NASA Lewis Research Center, Cleveland, OH under Contract No. DEN3-335.


2009 ◽  
Author(s):  
P.R.F. de M. Bastos ◽  
N. Ferreira ◽  
B.A. de Souza

2020 ◽  
Vol 12 (17) ◽  
pp. 2809
Author(s):  
Meirman Syzdykbayev ◽  
Bobak Karimi ◽  
Hassan A. Karimi

Detection of terrain features (ridges, spurs, cliffs, and peaks) is a basic research topic in digital elevation model (DEM) analysis and is essential for learning about factors that influence terrain surfaces, such as geologic structures and geomorphologic processes. Detection of terrain features based on general geomorphometry is challenging and has a high degree of uncertainty, mostly due to a variety of controlling factors on surface evolution in different regions. Currently, there are different computational techniques for obtaining detailed information about terrain features using DEM analysis. One of the most common techniques is numerically identifying or classifying terrain elements where regional topologies of the land surface are constructed by using DEMs or by combining derivatives of DEM. The main drawbacks of these techniques are that they cannot differentiate between ridges, spurs, and cliffs, or result in a high degree of false positives when detecting spur lines. In this paper, we propose a new method for automatically detecting terrain features such as ridges, spurs, cliffs, and peaks, using shaded relief by controlling altitude and azimuth of illumination sources on both smooth and rough surfaces. In our proposed method, we use edge detection filters based on azimuth angle on shaded relief to identify specific terrain features. Results show that the proposed method performs similar to or in some cases better (when detecting spurs than current terrain features detection methods, such as geomorphon, curvature, and probabilistic methods.


Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 709
Author(s):  
Uwe Zerbst ◽  
Mauro Madia ◽  
Giovanni Bruno ◽  
Kai Hilgenberg

The safe fatigue design of metallic components fabricated by additive manufacturing (AM) is still a largely unsolved problem. This is primarily due to (a) a significant inhomogeneity of the material properties across the component; (b) defects such as porosity and lack of fusion as well as pronounced surface roughness of the as-built components; and (c) residual stresses, which are very often present in the as-built parts and need to be removed by post-fabrication treatments. Such morphological and microstructural features are very different than in conventionally manufactured parts and play a much bigger role in determining the fatigue life. The above problems require specific solutions with respect to the identification of the critical (failure) sites in AM fabricated components. Moreover, the generation of representative test specimens characterized by similar temperature cycles needs to be guaranteed if one wants to reproducibly identify the critical sites and establish fatigue assessment methods taking into account the effect of defects on crack initiation and early propagation. The latter requires fracture mechanics-based approaches which, unlike common methodologies, cover the specific characteristics of so-called short fatigue cracks. This paper provides a discussion of all these aspects with special focus on components manufactured by laser powder bed fusion (L-PBF). It shows how to adapt existing solutions, identifies fields where there are still gaps, and discusses proposals for potential improvement of the damage tolerance design of L-PBF components.


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