STP995V1: Evaluation of the Ct Parameter for Characterizing Creep Crack Growth Rate in the Transient Regime

    Bassani, JL
    Associate professor, University of Pennsylvania, Philadelphia, PA

    Hawk, DE
    Graduate research assistantresearch,

    Saxena, A
    Professor, Schools of Materials Engineering,,

    Pages: 20    Published: Jan 1988


    Abstract

    An in-depth evaluation of the Ct parameter, which has been proposed for characterizing the creep crack growth behavior under small-scale-creep (transient) to extensive creep conditions, is conducted. The evaluation includes a thorough examination of the assumptions made in the definition of Ct, an experimental evaluation, and a finite-element analysis of a compact specimen used in an actual creep crack growth experiment.

    The experimental correlations between da/dt and Ct are extremely encouraging. Ct is interpreted as the stress-power (or energy rate) release rate during crack extension. Under extensive creep conditions, Ct therefore equals C*, which is given in terms of a path-independent integral as well as the stress-power release rate. Under small-scale creep, Ct is shown to characterize the rate of growth of the creep zone. More finite-element analyses and experiments under highly transient conditions are recommended for completing the understanding of the creep crack growth behavior in this regime.

    Keywords:

    creep, crack, transient regime, Ct, parameter, Cr-Mo-V steel, fracture mechanics, nonlinear fracture mechanics


    Paper ID: STP26768S

    Committee/Subcommittee: E08.06

    DOI: 10.1520/STP26768S


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