STP803V1: Ductile Growth of Part-Through Surface Cracks: Experiment and Analysis

    White, CS
    Graduate fellow and associate professors of mechanical engineeringprofessor1st lieutenant, Department of Mechanical Engineering, Massachusetts Institute of TechnologyUniversity of CaliforniaU.S. Army, Materials and Mechanics Research Center, CambridgeBerkeleyWatertown, Mass.Calif.Mass.

    Ritchie, RO
    Graduate fellow and associate professors of mechanical engineeringprofessor1st lieutenant, Department of Mechanical Engineering, Massachusetts Institute of TechnologyUniversity of CaliforniaU.S. Army, Materials and Mechanics Research Center, CambridgeBerkeleyWatertown, Mass.Calif.Mass.

    Parks, DM
    Graduate fellow and associate professors of mechanical engineeringprofessor1st lieutenant, Department of Mechanical Engineering, Massachusetts Institute of TechnologyUniversity of CaliforniaU.S. Army, Materials and Mechanics Research Center, CambridgeBerkeleyWatertown, Mass.Calif.Mass.

    Pages: 26    Published: Jan 1983


    Abstract

    It is an essentially open question as to how well characterizations of through-thickness crack growth based on parameters such as J, crack-tip opening displacement, and tearing modulus describe ductile cracking in important structural configurations such as the part-through surface-cracked plate.

    In this work we compare experimental observations and predictions of ductile crack extension in surface-cracked plates subject to bending. Predictions are made by performing finite-element analysis of this three-dimensional geometry using the line-spring model, in conjunction with experimental plane-strain crack growth data from R-curves obtained from through-thickness-cracked compact-tension specimens.

    Analysis of the surface flaw is based upon the incremental plasticity theory line-spring element, which has been incorporated into the ABAQUS© general-purpose finite-element program.

    The material under study is a low-alloy bainitic pressure vessel steel; namely, fossil energy ASTM A542, Class 3.

    Results show that for the crack configuration considered here the amount of stable tearing is quite uniform along the crack front as is the local value of the J-integral. Crack growth initiation occurs at similar J's for both through-crack and surface-crack specimens, but the surface-crack specimens tested exhibit a higher apparent tearing modulus.

    Keywords:

    stable crack growth, fracture, plastic properties, surface crack, line spring, J-integral, resistance curves, elastic-plastic fracture


    Paper ID: STP37305S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP37305S


    CrossRef ASTM International is a member of CrossRef.