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Advanced Characterization Techniques that Improve Durability of Fracture Critical DoD Components
Navy SBIR 2008.1 - Topic N08-065 ONR - Mrs. Tracy Frost - [email protected] Opens: December 10, 2007 - Closes: January 9, 2008 N08-065 TITLE: Advanced Characterization Techniques that Improve Durability of Fracture Critical DoD Components TECHNOLOGY AREAS: Air Platform, Materials/Processes ACQUISITION PROGRAM: F135 Joint Strike Fighter Program. OBJECTIVE: Develop and apply advanced fracture mechanics and thermal-mechanical fatigue (TMF) characterization tools and techniques addressing the variability and mission simulation issues below. This would result in increased fidelity assessments and improved durability management of fracture critical DoD components DESCRIPTION: Many DoD systems employ fracture critical and/or retirement for cause methodologies for asset deployment, operation and management. They are a key element in the design and certification of turbine engines including the F100, F119, and F135. A key element in this approach is the characterization of structural materials and development of life prediction methodologies and then application of these to component design, validation and assessment. In structural metallic systems fracture mechanics approaches provide the foundation for this assessment, however variability and uncertainty are introduced due to the presence of many factors including residual stresses, material variability, complex damage environments, etc. These factors can influence life assessments by factors of four or more. In addition, mission cycles for hot section components such as turbine airfoils are quite complex and test methodologies such as TMF have not been sufficiently standardized and matured to provide repeatable results across a broad range of facilities and environments. This challenge is exacerbated by the complex loading profiles these components experience. This can lead to loss of durability in key hot section components. The goal of this topic is to develop, demonstrate and validate advanced fatigue and fracture characterization techniques and analytical tools resulting in refined assessments of turbine durability. PHASE I: Demonstrate in a laboratory environment the feasibility of the test techniques through demonstration of reduced variability and accurate capture of complex cycle damage mechanisms. Develop a business case and development program plan that would support further investment of this approach. PHASE II: Clearly develop and demonstrate a prototype test system including software, hardware and associated analytical tools to provide more robust characterization of fracture critical DoD components. Validate the performance of the system at several industrial test facilities. PHASE III: Incorporate improvements and modifications based on the prototype system validated in Phase II into a commercially available product. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Hot section material durability and fracture critical designs play key roles in commercial turbine engine systems. The tools and techniques should be directly applicable to commercial applications. REFERENCES: 2. Renauld, M.L., Scott, J.A., Favrow, L.H., McGaw, M.A., Marotta, D., and Nissley, D.M.: "An Automated Facility for Advanced Testing of Materials," Applications of Automation Technology in Fatigue and Fracture Testing and Analysis, ASTM STP 1411, A. A. Braun, P. C. McKeighan, M. A. Nicolson, and P. R. Lohr, Eds., American Society for Testing and Materials, West Conshohocken, PA, 2002 3. Halford, G.R., Lerch, B.A., and McGaw, M.A.: "Fatigue, Creep-Fatigue, and Thermomechanical Fatigue Life Testing", ASM Handbook, Volume 8, Mechanical Testing and Evaluation, H. Kuhn and D. Medlin, Eds. ASM International, Materials Park, Ohio, 44073-0002, pp. 686-716. KEYWORDS: TMF, fracture mechanics, mechanical behavior, thermo-mechanical fatigue, durability, life prediction modeling TPOC: David Shifler
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