The Electrostriction Interface
The Electrostriction interface (), found under Electromagnetics–Structure Interaction () branch within the Structural Mechanics branch () or the Electromagnetics and Mechanics () branch within the AC/DC branch () when adding a physics interface, combines Solid Mechanics and Electrostatics together with the constitutive relationships required to model electrostriction in electrostatically actuated structures in regimes when the electric polarization can be assumed to vary linear with the applied electric field. Both the direct and inverse electrostrictive effects can be modeled.
The Electrostriction interface is available for 3D, planar 2D, and axisymmetric 2D geometries.
When this multiphysics interface is added using the Model Wizard, a Solid Mechanics interface and an Electrostatics interface are added to the Model Builder.
In addition, the Multiphysics node is added, which automatically includes the multiphysics coupling feature Electrostriction.
All structural and electrostatics functionality for modeling is also accessible to include surrounding solids, fluids, or free space. For example, add any material model for other solid domains, a dielectric model for fluid, or a combination.
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 Electrostatic interface is described in The Electrostatics Interface in the AC/DC Module User’s Guide.
Settings for Physics Interfaces and Coupling Features
When physics interfaces are added using the predefined couplings, for example Electrostriction, specific settings are included with the physics interfaces and the coupling features.
However, if physics interfaces are added one at a time, followed by the coupling features, these modified settings are not automatically included.
For example, if both Solid Mechanics and Electrostatics interfaces are added, COMSOL Multiphysics adds an empty Multiphysics node. You can add the available coupling feature Electrostriction but the modified settings are not included.
The Electrostatics interface by default adds the Charge Conservation in Solids node with its selection set to all domains. This node serves to represent solid dielectric material domains. Any number of Charge Conservation in Solids or Charge Conservation in Fluids nodes can be added to the interface.
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Electrostriction
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Modeling Electrostrictive and Ferroelectroelastic Materials