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Effect of Measured Welding Residual Stresses on Crack GrowthWelding residual stresses in thin plate A516-70 steel and 2219-T87 aluminum butt weldments were measured by the strain-gage hole drilling and X-ray diffraction methods. The residual stress data were used to construct 3D strain fields which were modeled as thermally induced strains. These 3D strain fields were then analyzed with the WARP31) FEM fracture analysis code in order to predict their effect on fatigue and on fracture. For analyses of fatigue crack advance and subsequent verification testing, fatigue crack growth increments were simulated by successive saw-cuts and incremental loading to generate, as a function of crack length, effects on crack growth of the interaction between residual stresses and load induced stresses. The specimen experimental response was characterized and compared to the WARM linear elastic and elastic-plastic fracture mechanics analysis predictions. To perform the fracture analysis, the plate material's crack tearing resistance was determined by tests of thin plate M(T) specimens. Fracture analyses of these specimen were performed using WARP31D to determine the critical Crack Tip Opening Angle [CTOA] of each material. These critical CTOA values were used to predict crack tearing and fracture in the weldments. To verify the fracture predictions, weldment M(T) specimen were tested in monotonic loading to fracture while characterizing the fracture process.
Document ID
20020070288
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Hampton, Roy W.
(NASA Ames Research Center Moffett Field, CA United States)
Nelson, Drew
(Stanford Univ. Stanford, CA United States)
Doty, Laura W.
Date Acquired
August 20, 2013
Publication Date
October 1, 1998
Subject Category
Metals And Metallic Materials
Meeting Information
Meeting: ASTM 31st National Symposium Fatigue and Fractures Mechanics
Location: Cleveland, OH
Country: United States
Start Date: June 22, 1999
End Date: June 24, 1999
Sponsors: American Society for Testing and Materials
Funding Number(s)
PROJECT: RTOP 297-10-02
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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