Application of elastic and elastic-plastic fracture mechanics methods to surface flaws

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6110200

McCabe, D E ^[1]; Ernst, H A ^[2]; Newman, Jr, J C ^[3]

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1. Oak Ridge National Lab., TN (USA)
2. Georgia Inst. of Tech., Atlanta, GA (USA). School of Mechanical Engineering
3. National Aeronautics and Space Administration, Hampton, VA (USA). Langley Research Center

Fuel tanks that are part of the External Tank assembly for the Space Shuttle are made of relatively thin 2219-T87 aluminum plate. These tanks contain about 917 m of fusion weld seam, all of which is nondestructively inspected for flaws and all those found are repaired. The tanks are subsequently proof-tested to a pressure that is sufficiently severe to cause weld metal yielding in a few local regions of the weld seam. The work undertaken in the present project was to develop a capability to predict flaw growth from undetected surface flaws that are assumed to be located in the highly stressed regions. The technical challenge was to develop R-curve prediction capability for surface cracks in specimens that contain the flaws of unusual sizes and shapes deemed to be of interest. The test techniques developed and the elastic-plastic analysis concepts adopted are presented. The flaws of interest were quite small surface cracks that were narrow-deep ellipses that served to exacerbate the technical difficulties involved. 9 refs., 15 figs., 5 tabs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• Sponsoring Organization: USDOE; National Aeronautic and Space Administration (NASA); USDOE, Washington, DC (USA); National Aeronautics and Space Administration, Washington, DC (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6110200
• Report Number(s): CONF-900610-2; ON: DE91009936
• Resource Relation: Conference: 22. national symposium on fracture mechanics, Atlanta, GA (USA), 26-28 Jun 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
WELDED JOINTS
CRACK PROPAGATION
FRACTURE MECHANICS
CONTAINERS
DEFECTS
ELASTICITY
FORECASTING
FRACTURE PROPERTIES
INSPECTION
PERFORMANCE TESTING
PLASTICITY
PLATES
SPACE SHUTTLES
SURFACES
YIELD STRENGTH
AIRCRAFT
ELEMENTS
JOINTS
MECHANICAL PROPERTIES
MECHANICS
METALS
SPACE VEHICLES
TENSILE PROPERTIES
TESTING
VEHICLES
360103* - Metals & Alloys- Mechanical Properties