PoroViscoElastic model to describe hydrogels' behavior

- Coupling poroelasticity and viscoelasticity to describe the behavior of hydrogels
- Model based on non-linear mechanics and non-equilibrium thermodynamics
- Parametric FEM simulations of hydration and stress-relaxation tests

Hydrogels are three-dimensional, cross-linked hydrophilic polymeric network able of absorb large amount of water. The mechanics of these systems is strictly coupled with the water transport resulting in the peculiar behavior known as poroviscoelasticy. This can be considered as sum of the viscoelastic behavior of the polymeric network and the poroelastic behavior caused by the water movement within the hydrogel. In this work a 3D monophasic model able to depict the poroviscoelastic behavior of these systems, within the field of nonlinear solid mechanics, is developed. The mass and momentum balances equations, supported by constitutive equations from non-equilibrium thermodynamics and by initial and boundary conditions, is implemented through the weak formulation in a commercial FEM-based software. A parametric study is performed in order to assess the relative importance of the model parameters on hydrogels' behavior.

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