Properties of a nonlinear viscoelastoplastic model of Maxwell type with two material functions

General qualitative properties of quasistatic curves for creep, relaxation, strain, and others are studied analytically. These curves are obtained on the basis of a one-dimensional constitutive relation of Maxwell type. Some constraints are proposed for the material functions to adequately describe the typical properties of experimental curves for a wide class of viscoelastoplastic materials. The applicability of the proposed model to describe, in particular, the superplastic deformation is analyzed. The effects that cannot be described in the framework of this model are found and its applicability range is revealed.