All the hyperelastic material models (Arruda-Boyce, Blatz-Ko, Hyperfoam, Mooney-Rivlin, Neo-Hookean, Ogden, Van der Waals, Yeoh) can be used in conjunction with a finite strain viscoelastic model. The viscoelastic material properties are listed below. Refer to the proper page for the hyperelastic material properties.
Elastic Moduli
This drop-down box is used to describe how the linear viscoelastic material is being loaded. If the material will be loaded slowly so that time-dependent behavior is negligible, select the Long-Term option. If the material will be loaded instantaneously, or as a step load, select the Instantaneous option.
Prony Series
The Prony series that will be used to calculate the viscoelastic effects will be defined by pressing the Prony Series Definition button. To apply a temperature shift, select the Williams-Landell-Ferry option in the Shift Function drop-down box. You must then define the reference and analysis temperatures and the constants used to define the shift in the appropriate fields.
If the volume and shape changes are not coupled, activate the Independent Volumetric/Deviatoric Relaxation check box. You can then define the relaxation moduli and relaxation times that will define the Prony series.