STP1189: Experimental Relationship Between Equivalent Plastic Strain and Constraint for Crack Initiation

    Reuter, WG
    Principal engineer, engineering specialist, and senior engineering specialists, Idaho National Engineering Laboratory, Idaho Falls, ID

    Lloyd, WR
    Principal engineer, engineering specialist, and senior engineering specialists, Idaho National Engineering Laboratory, Idaho Falls, ID

    Williamson, RL
    Principal engineer, engineering specialist, and senior engineering specialists, Idaho National Engineering Laboratory, Idaho Falls, ID

    Smith, JA
    Graduate student, Texas A&M University, College Station, TX

    Epstein, JS
    Principal engineer, engineering specialist, and senior engineering specialists, Idaho National Engineering Laboratory, Idaho Falls, ID

    Pages: 25    Published: Jan 1993


    Abstract

    The applicability of fracture mechanics data generated from standard fracture toughness specimens in predicting structural integrity is often a concern. For elastic-plastic conditions, a second parameter identified as “constraint” (hydrostatic stress divided by the equivalent stress) is being used to link different specimen/flaw configurations, thus providing a mechanism for using data generated from standard fracture toughness specimens to predict structural integrity. Much of the literature is concerned with the difference in constraint between specimens and a structure, while little effort is being given to investigating the sensitivity of the crack initiation process to constraint for a given material. This paper presents experimental results relating crack initiation processes to constraint for a ferritic steel and an aluminum-based alloy.

    Keywords:

    tension tests, equivalent plastic strain, constraint, crack initiation, fracture mechanics


    Paper ID: STP24264S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP24264S


    CrossRef ASTM International is a member of CrossRef.