Defining Long-term and Instantaneous Moduli in Viscoelastic Models

Is it possible to define long-term and instantaneous moduli in viscoelastic materials?

The elastic properties (isotropic elastic or hyperelastic) that are defined along with the viscoelastic properties are the instantaneous responses. Currently there is no way of defining the long-term response, but there is a simple workaround for this.

For more details, please refer to the document below.