The Poroelasticity, Solid Interface
The Poroelasticity, Solid Interface
The Poroelasticity, Solid interface () combines a transient formulation of Darcy’s law with a quasistatic formulation of Solid Mechanics under isothermal conditions. The coupling occurs on the domain level, where the pore pressure from the Darcy’s Law interface acts as a load for the Solid Mechanics interface, causing swelling or shrinkage. Changes in volumetric strain affect the porosity, acting as a mass source or sink in Darcy’s law.
When a predefined Poroelasticity, Solid interface is added from the Structural Mechanics branch () of the Model Wizard or Add Physics windows, the Solid Mechanics and Darcy’s Law interfaces are added to the Model Builder.
In addition, the Multiphysics node is added, which automatically includes the Poroelasticity multiphysics coupling.
On the Constituent Physics Interfaces
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The Solid Mechanics interface is described in The Solid Mechanics Interface.
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The Darcy’s Law interface is described in The Darcy’s Law Interface.
To model orthotropic or anisotropic porous materials requires the Structural Mechanics Module. For information about the constitutive equations and theory background, see Structural Mechanics Theory.
The Poroelasticity multiphysics coupling handles both geometrically linear and nonlinear problems automatically according to the settings in material model used in the Solid Mechanics interface. In the default Linear Elastic Material node, geometric nonlinearity is controlled by the Formulation list. By default, it is set to From study step. Changing this setting to Total Lagrangian forces the checkbox Include geometric nonlinearity in the study step to be selected and grayed out.
Conversely, select Geometrically linear in the Formulation list to enforce a small strain formulation, even if the checkbox Include geometric nonlinearity is selected in the study. See Geometric Nonlinearity for the Solid Mechanics Interface in the Structural Mechanics Module User’s Guide.
Settings for Physics Interfaces and Coupling Features
When physics interfaces are added using the predefined couplings, for example Poroelasticity, specific settings are included with the physics interfaces and the coupling features.
However, if the physics interfaces are added one at a time, followed by the coupling features, these modified settings are not automatically included.
For example, if single Solid Mechanics and Darcy’s Law interfaces are added, an empty Multiphysics node appears in the model tree. You can choose from the available coupling features, but the settings in the constituent interfaces are not modified.
Table 15-8: Modified Settings for a Poroelasticity interface.
Physics Interface or Coupling Feature
Modified Settings
Solid Mechanics
For the Solid Mechanics interface, under Structural Transient Behavior, the Structural transient behavior is set to Quasistatic.
Darcy’s Law
For the Darcy’s Law interface, a Poroelastic storage model is added by default.
Poroelasticity
The Domain Selection is the same as that of the participating physics interfaces.
The corresponding Solid Mechanics and Darcy’s Law interfaces are preselected in the Coupled Interfaces section.
 
Failure of a Multilateral Well: Application Library path Subsurface_Flow_Module/Poromechanics/multilateral_well
Large Swelling in Polymer Hydrogels: Application Library path Porous_Media_Flow_Module/Poromechanics/hydrogel_swelling