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Unformatted text preview: AAE 552 Spring 2009 A. F. Grandt 1 1 AAE 552: Nondestructive Evaluation of Structures and Materials A. F. Grandt, Jr. Professor of Aeronautics and Astronautics Purdue University W. Lafayette, IN 47907 Session 9 2 February 2009 2 Contact Information Alten F. (Skip) Grandt, Jr. Email: [email protected] Telephone: Office: 765-494-5141 Home: 765-463-4276 FAX: 765-494-0307 Course webpage accessed at: http://www.itap.purdue.edu/tlt/blackboard 3 AAE 552 Session 9 2 February 2009 Last Time: NDE design requirements Today: Evaluating maturity of technology Overview LEFM 4 Assignment Please read Textbook : Chapter 16.1 16.3, 16.5, 16.7-16.9 Skim Chapter 3 AAE 552 Class Demographics Spring 2009 5 campus ugrad 21 campus grad 19 ProEd grad 26 total 66 40 campus 26 ProEd 66 total AL 3 CA 1 CT 2 FL 1 GA 1 IA 1 IN 4 KS 1 MD 1 NY 1 OH 2 OK 2 WA 3 India 2 Qatar 1 total 26 ProEd Location 13 states 2 International locations 17 different companies International AAE 552 ProEd Locations 6 Doha, QATAR Bangalore, India Purdue AAE 552 Spring 2009 A. F. Grandt 2 7 Design Requirements (Section 16.2.2, p 448) USAF Aircraft: MIL-A-83444 Airplane Damage Tolerance Requirements [July 1974]. This specification contains the damage tolerance design requirement applicable to airplane safety of flight structure. The objective is to protect the safety of flight structure from potentially deleterious effects of material, manufacturing and processing defects through proper material selection and control, control of stress levels, use of fracture resistant design concepts, manufacturing and process controls and the use of careful inspection procedures . . . . . . . The analyses shall assume the presence of flaws placed in the most unfavorable location and orientation with respect to the applied stresses and material properties. 8 NASA Spacecraft NDE Guidelines (MSFC-STD-1249 - see AAE 552 webpage and text 16.2.2) Scope: MSFC-STD-1249 provides NDE guidelines for spacecraft fracture control plans Gives minimum crack-like flaws reliably found by traditional NDE 90/95 probability/confidence methods: Penetrant Eddy Current Magnetic Particle Ultrasonics Radiography (manual) 9 Inspection Requirements (Section 16.2.2, p 449) NASA Space Craft (Cont) MSFC-STD-1249 The Fracture Control Program concept dictates that fracture mechanics design assessments of aerospace structures and pressure vessels assume the potential existence of crack-like flaws in crucial, higher stressed zones of hardware. Mission fulfillment expectations are thus confirmed by fracture mechanics calculations of acceptable maximum size initial crack-like flaws (Critical Initial Flaw Size CIFS) that would not grow to catastrophic-failure size within the number of cyclic exposures dictated for mission assurance. NDE then is obligated to assure that the CIFS does not exist in the newly fabricated hardware. 10 Inspection Requirements...
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This note was uploaded on 11/04/2010 for the course AAE 552 taught by Professor Longuski during the Spring '10 term at IUPUI.
- Spring '10