ABAQUS Volume II: I–Z - Manual (Page 608)

*VISCOELASTIC
TIME
Use this parameter to choose the time domain definition. In this case the material’s elasticity must
be defined using the *ELASTIC, the *HYPERELASTIC, or the *HYPERFOAM option.
Set TIME=CREEP TEST DATA if the Prony series parameters are to be computed by
ABAQUS from data taken from shear and volumetric creep tests.
Set TIME=FREQUENCY DATA if the Prony series parameters are to be computed by
ABAQUS from frequency-dependent cyclic test data.
Set TIME=PRONY to define a linear, isotropic, viscoelastic material by giving the parameters
of the Prony series representation of the relaxation moduli.
Set TIME=RELAXATION TEST DATA if the Prony series parameters are to be computed by
ABAQUS from data taken from shear and volumetric relaxation tests.
Optional parameters:
PRELOAD
This parameter applies only to ABAQUS/Standard analyses.
This parameter can be used only in conjunction with FREQUENCY=TABULAR to specify the
nature of preload used for defining frequency-domain viscoelastic material properties or effective
thickness-direction gasket properties.
Set PRELOAD=UNIAXIAL to specify that the frequency-domain viscoelastic material
properties correspond to a uniaxial test.
Set PRELOAD=VOLUMETRIC to specify that the frequency-domain viscoelastic material
properties correspond to a volumetric test. This setting is not meaningful when used with gasket
elements to define effective thickness-direction properties.
TYPE
Use this parameter to define whether the *VISCOELASTIC option is being used to define
continuum material properties or effective thickness-direction gasket properties.
Set TYPE=ISOTROPIC (default, and only option for ABAQUS/Explicit) to define continuum
material properties. This choice is appropriate when the viscoelasic material model is used for
any continuum, structural, or special-purpose elements whose material response is modeled using
continuum material properties (examples of such special-purpose elements include modeling
cohesive elements with a continuum response—see “Modeling of an adhesive layer of finite
thickness” in “Defining the constitutive response of cohesive elements using a continuum
approach,” Section 26.5.5 of the ABAQUS Analysis User’s Manual, or gasket elements with a
material response—see “Defining the gasket behavior using a material model,” Section 26.6.5 of
the ABAQUS Analysis User’s Manual).
Set TYPE=TRACTION to define effective thickness-direction gasket properties. This option
is supported only for gasket elements whose behavior is modeled directly using a gasket behavior
model (“Defining the gasket behavior directly using a gasket behavior model,” Section 26.6.6 of
the ABAQUS Analysis User’s Manual).
21.4–2
ABAQUS Version 6.1 Module: ID:
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