STP1296: Fracture Analysis of Full-Thickness Clad Beam Specimens

    Keeney, JA
    Engineers, Oak Ridge National Laboratory, Oak Ridge, TN

    Bass, BR
    Engineers, Oak Ridge National Laboratory, Oak Ridge, TN

    McAfee, WJ
    Engineers, Oak Ridge National Laboratory, Oak Ridge, TN

    Pages: 20    Published: Jan 1997


    Abstract

    Finite-element analyses were performed on full-thickness clad beam specimens to quantify fracture toughness for shallow cracks in material for which metallurgical conditions are prototypic of those found in reactor pressure vessels (RPVs). The beam specimens are fabricated from a section of an RPV wall (removed from a canceled nuclear plant) that includes weld, plate, and clad material with metallurgical factors potentially influencing fracture toughness for shallow cracks. A summary of the testing program is provided and the analyses of the test data are discussed, including comparisons of measured displacements with finite-element analysis results, applications of toughness estimation techniques, and interpretations of constraint conditions implied by stress-based constraint methodologies. Fracture toughness estimates were obtained from displacement data using finite-element techniques and estimation schemes based on the η-factor method. The J-Q methodology was used to assess crack-tip stress triaxiality in the clad beam specimens. The shallow-crack clad beam specimens showed a significant loss of constraint similar to that of other shallow-crack single-edge notch bend specimens. The stress-based Dodds-Anderson scaling model was also utilized to analyze constraint conditions in the clad beam specimens and appears to be effective in adjusting the test data to account for loss of in-plane constraint for uniaxially tested beams.

    Keywords:

    reactor pressure vessel, full-thickness clad beams, shallow crack, single-edge notch bend specimens, constraint, η-factor method, J-Q, methodology, crack-tip stress triaxiality


    Paper ID: STP16244S

    Committee/Subcommittee: E08.04

    DOI: 10.1520/STP16244S


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