STP803V2: Ductile Fracture of Circumferentially Cracked Pipes Subjected to Bending Loads

    Zahoor, A
    Supervising engineer, EDS Nuclear Inc., Bethesda, Md.

    Kanninen, MF
    Research leader, Battelle Columbus Laboratories, Columbus, Ohio

    Pages: 18    Published: Jan 1983


    Abstract

    A plastic fracture mechanics methodology is presented for part-through cracks in pipes under bending. A previous analysis result on the behavior of part-through cracks in pipes is reviewed. Example quantitative results for the initiation and instability of radial growth of part-through cracks are presented and compared with the experimental data to demonstrate the applicability of the method. The analyses in our previous work are further developed to include the instability of circumferential growth of part-through cracks. Numerical results are then presented for a compliant piping system, under displacement controlled bending, which focus on (1) instability of radial growth (unstable wall breakthrough) and (2) instability of circumferential growth of the resulting through-the-thickness crack. The combined results of the above two types of analyses are presented on a safety assessment diagram. This diagram defines a curve of critical combination of length and depth of part-through cracks which delineates leak from fracture. The effect of piping compliance on the leak-before-break assessment is discussed.

    Keywords:

    ductile fracture, degraded piping, part-through cracks, J-integral/tearing modulus, J, -resistance curve, unstable wall breakthrough, leak-before-break, safety assessment diagram, elastic-plastic fracture


    Paper ID: STP36773S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP36773S


    CrossRef ASTM International is a member of CrossRef.