STP856: Alternative Displacement Procedures for J-R Curve Determination

    Hiser, AL
    Engineer and technical director, Materials Engineering Associates, Inc., Lanham, MD

    Loss, FJ
    Engineer and technical director, Materials Engineering Associates, Inc., Lanham, MD

    Pages: 15    Published: Jan 1985


    Abstract

    This investigation evaluates alternative displacement techniques with the single-specimen compliance (SSC) procedure, which do not require the commonly used load-line displacement measurements in a compact toughness (CT) specimen to determine the J-R curve. The two techniques studied are a double clip gage technique involving both crack-mouth displacement and load-line displacement at the edges of the specimen and a technique that requires only crack-mouth displacement. J-R curves developed using these techniques are compared to J-R curves developed with the normal load-line based deflections. In addition, results of a round-robin program using the SSC procedure are discussed in terms of validating the double clip gage technique. J-R curves developed from crackmouth displacements on the J-integral specimen from ASTM Test for JIc, a Measure of Fracture Toughness (E 813) suggest that the ASTM Test Method for Plane-Strain Fracture Toughness of Metallic Materials (E 399) specimen design can be used for both linear-elastic (for example, KIc) and elastic-plastic (for example, J-R curve) toughness assessments. This fact can be of particular value in the testing of reactor surveillance specimens that may not have been machined to permit load-line displacement measurements.

    Keywords:

    fracture tests, displacement, elasticity, J-R, curve, elastic-plastic fracture, single-specimen compliance procedure, double clip gage technique, nuclear pressure vessel steel


    Paper ID: STP34529S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP34529S


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