version 3.10-dev
geomechanics/poroelastic/model.hh File Reference

A poroelastic geomechanical model. More...

Go to the source code of this file.

Description

This model describes the deformation of a porous medium using the theory of linear poroelasticity. The momentum balance equation of a porous medium can be expressed by

\[ \nabla\cdot\boldsymbol{\sigma_{\mathrm{eff}}} + \rho \mathbf{g} + \mathbf{f} = \rho\ddot{\mathbf{u}}, \]

where \( \boldsymbol{\sigma_{\mathrm{eff}}} \) is the effective stress tensor, \( \rho = (1 - \phi) \rho_s + \phi \rho_f \) is the average density of solids and fluids within the porous medium, \( \mathbf{f} \) in \( \mathrm{N/m^3} \) is the external force acting on the body per unit volume (e.g. magnetism), and \( \mathbf{u} = \mathbf{x} - \mathbf{x}_{\mathrm{initial}} \) is the displacement, defined as the difference in material points \( \mathbf{x} \) and \( \mathbf{x}_{\mathrm{initial}} \) in the deformed and undeformed (initial) state, respectively. The model assumes quasi-static conditions, that is, the above momentum balance equation is solved under the assumption that the acceleration term \( \rho\ddot{\mathbf{u}} \approx 0\).

Using the concept of the effective stress, the effective stress tensor \( \boldsymbol{\sigma_{\mathrm{eff}}} \) is determined by the stress tensor \( \boldsymbol{\sigma} \) , the effective pore pressure \( p_{\mathrm{eff}} \) and the Biot's coefficient \( \alpha \) :

\[ \boldsymbol{\sigma_{\mathrm{eff}}} = \boldsymbol{\sigma} - \alpha p_{\mathrm{eff}} \mathbf{I} \]

Per default, Hookes' Law is used for expressing the stress tensor \( \boldsymbol{\sigma} \) as a function of the displacement:

\[ \boldsymbol{\sigma} = \lambda\mathrm{tr}(\boldsymbol{\varepsilon}) \mathbf{I} + 2G \boldsymbol{\varepsilon}, \]

with

\[ \boldsymbol{\varepsilon} = \frac{1}{2} \left[ \nabla\mathbf{u} + (\nabla\mathbf{u})^{\mathrm{T}} \right]. \]

Primary variables are the displacements in each direction \( \mathbf{u} \). Gravity can be enabled or disabled via a runtime parameter.

Classes

struct  Dumux::PoroElasticModelTraits< dim, numSC, numFP, numFC >
 Specifies a number properties of the poroelastic model. More...
 
struct  Dumux::Properties::TTag::PoroElastic
 
struct  Dumux::Properties::LocalResidual< TypeTag, TTag::PoroElastic >
 Use the local residual of the poro-elastic model. More...
 
struct  Dumux::Properties::IOFields< TypeTag, TTag::PoroElastic >
 default vtk output fields specific to this model More...
 
struct  Dumux::Properties::ModelTraits< TypeTag, TTag::PoroElastic >
 The default model traits of the poro-elastic model. More...
 
struct  Dumux::Properties::VolumeVariables< TypeTag, TTag::PoroElastic >
 Set the volume variables property. More...
 
struct  Dumux::Properties::StressType< TypeTag, TTag::PoroElastic >
 Per default, we use effective stresses on the basis of Hooke's Law. More...
 

Namespaces

namespace  Dumux
 
namespace  Dumux::Properties
 The energy balance equation for a porous solid.
 
namespace  Dumux::Properties::TTag
 Type tag for numeric models.
 
Include dependency graph for geomechanics/poroelastic/model.hh: