# Rate-dependent plasticity: creep and swelling

 The classical deviatoric metal creep behavior in Abaqus/Standard: can be defined using user subroutine CREEP or by providing parameters as input for some simple creep laws; can model either isotropic creep (using Mises stress potential) or anisotropic creep (using Hill's anisotropic stress potential); is active only during steps using the coupled temperature-displacement procedure, the transient soils consolidation procedure, and the quasi-static procedure; requires that the material's elasticity be defined as linear elastic behavior; can be modified to implement the auxiliary creep hardening rules specified in Nuclear Standard NEF 9-5T, “Guidelines and Procedures for Design of Class 1 Elevated Temperature Nuclear System Components”; these rules are exercised by means of a constitutive model developed by Oak Ridge National Laboratory (ORNL – Oak Ridge National Laboratory constitutive model); can be used in combination with creep strain rate control in analyses in which the creep strain rate must be kept within a certain range; and can potentially result in errors in calculated creep strains if anisotropic creep and plasticity occur simultaneously (discussed below). Rate-dependent gasket behavior in Abaqus/Standard: uses unidirectional creep as part of the model of the gasket's thickness-direction behavior; can be defined using user subroutine CREEP or by providing parameters as input for some simple creep laws; is active only during steps using the quasi-static procedure; and requires that an elastic-plastic model be used to define the rate-independent part of the thickness-direction behavior of the gasket. Volumetric swelling behavior in Abaqus/Standard: can be defined using user subroutine CREEP or by providing tabular input; can be either isotropic or anisotropic; is active only during steps using the coupled temperature-displacement procedure, the transient soils consolidation procedure, and the quasi-static procedure; and requires that the material's elasticity be defined as linear elastic behavior. The following topics are discussed:
 Related Topics About the material library Inelastic behavior In Other Guides Defining the gasket behavior directly using a gasket behavior model *CREEP *CREEP STRAIN RATE CONTROL *POTENTIAL *SWELLING *RATIOS Defining a creep law Defining swelling

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