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*TRS
Used to define temperature-time shift for time history viscoelastic analysis.

This option can be used only in conjunction with the *VISCOELASTIC option and, in Abaqus/Explicit, with the *VISCOSITY option.

In an Abaqus/Standard analysis, either the nonlinear viscoelasticity must be defined by using the *VISCOELASTIC, NONLINEAR option or viscoelasticity must be defined in the time domain by using the *VISCOELASTIC, TIME option.

Products: Abaqus/Standard  Abaqus/Explicit  Abaqus/CAE  

Type: Model data

Level: Model  

Abaqus/CAE: Property module

References:

Optional parameters:

DEFINITION

Set DEFINITION=WLF (default) to define the shift function by the Williams-Landel-Ferry approximation.

Set DEFINITION=ARRHENIUS to define the shift function by the Arrhenius approximation.

Set DEFINITION=USER to define the shift function in user subroutines. In Abaqus/Standard analyses define the shift function in user subroutine UTRS for the linear viscoelastic model (see “Time domain viscoelasticity,” Section 22.7.1 of the Abaqus Analysis User's Guide) or in user subroutine UTRSNETWORK for the nonlinear viscoelastic model defined using the parallel rheological framework (see “Parallel rheological framework,” Section 22.8.2 of the Abaqus Analysis User's Guide). In Abaqus/Explicit analyses define the shift function in user subroutine VUTRS for the linear viscoelastic model.

PROPERTIES

This parameter applies only to Abaqus/Explicit analyses and to Abaqus/Standard analyses if user subroutine UTRSNETWORK is used to define the shift function.

Set this parameter equal to the number of properties being entered. The properties are available for use in user subroutines VUTRS or UTRSNETWORK.

Data line to define the shift function by the Williams-Landel-Ferry approximation: 

First (and only) line:

  1. Reference temperature, .

  2. Calibration constant, .

  3. Calibration constant, .

Data line to define the shift function by the Arrhenius approximation: 

First (and only) line:

  1. Reference temperature, .

  2. Activation energy, .

In addition, you need to specify the universal gas constant and absolute zero using the *PHYSICAL CONSTANTS option.

Data lines to define material properties for a user-defined shift function (DEFINITION=USER): 

No data lines are needed if the PROPERTIES parameter is omitted or set to 0. Otherwise, first line:

  1. Enter the material properties, eight per line.

Repeat this data line as often as necessary to define all material properties.