Viscoelastic Material Model
Model ID: 208
Viscoelastic materials have a time-dependent response, even if the loading is constant. Many polymers and biological tissues exhibit such a behavior. Linear viscoelasticity is a commonly used approximation, where the stress depends linearly on the strain and its time derivatives.
For many materials, the viscoelastic properties have a strong dependence on the temperature. A common assumption is that the material is thermorheologically simple (TRS). In a material of this class, a change in the temperature can be transformed directly into a change in the time scale.
In this model, the geometry consists of a long thick-walled cylinder with inner diameter 5 mm and outer diameter 10 mm. The inner surface is subjected to a prescribed radial displacement of 0.001 mm. The model shows the decay of the stresses during a period of two hours.