STP1191: Viscoplasticity Theory Based on Overstress: The Modeling of Biaxial Cyclic Hardening Using Irreversible Plastic Strain

    Choi, SH
    Graduate studentmanager, Mechanics of Materials Laboratory, Rensselaer Polytechnic InstituteDAEWOO Group, TroySeoul, NY

    Krempl, E
    Professor, Mechanics of Materials Laboratory, Rensselaer Polytechnic Institute, Troy, NY

    Pages: 14    Published: Jan 1993


    Abstract

    Cyclic hardening behavior of stainless steel under various loading paths is modeled by using the small-strain, isotropic theory of viscoplasticity based on overstress. The cyclic hardening is modeled by postulating a growth law of an internal variable which is equivalent to isotropic hardening of yield surface plasticity. The growth of the hardening variable is formulated in a discrete way by using changes in the direction vector of the inelastic strain rate and the concept of irreversible plastic strain. The irreversible plastic strain is given as a function of variables representing amplitude, nonproportionality, and the history of the loading path. This formulation does not use separate growth laws for proportional and nonproportional loading. They are handled by a difference of the direction vectors of inelastic strain rate before and after it changes its direction. The capability of the model is demonstrated by numerical experiments for various loading conditions.

    Keywords:

    viscoplasticity, numerical experiments, cyclic hardening, path dependence, irreversible plastic strain, cross hardening, extra hardening


    Paper ID: STP24806S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP24806S


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