Electromechanical Forces

) coupling to model electromechanical interaction between deformable solids and electric fields, particularly in case when the deformations of the structure can significantly affect the electric field distribution.


	The presence of such multiphysics node in the model will enforce the Include geometric nonlinearity option on all applicable study nodes.

Settings

The is the default multiphysics coupling feature name.

The is used primarily as a scope prefix for variables defined by the coupling node. Refer to such variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different coupling nodes or physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the field. The first character must be a letter.

The default (for the first multiphysics coupling feature in the model) is eme1.

Domain Selection

The domain selection is locked, so that all applicable domains are selected automatically. Such domains represent an intersection of the applicable domains under the corresponding and interfaces selected in the coupling feature.

In interface, the following two domains are applicable:

•

, if its material type input is set to . Use this domain feature for solid dielectric materials.

•

. You can use the domain terminal feature to represent conductive solid materials such as, for example, doped silicon.

In interface, the following domain material feature are applicable:

•

(with the Nonlinear Structural Materials Module)

•

(with the Nonlinear Structural Materials Module).


	For nonsolid dielectric domains, remove them from the Solid Mechanics interface selection but keep them selected in the Electrostatics interface selection.

electromagnetic stress

To display this section, click the button (

) and select in the dialog box.

Here, you can select the to be used in the coupling. The following options are available:

•

(default)

•

See About different stress forms chapter for more details.

Coupled interfaces

This section defines the physics interfaces involved in this Electromechanical Forces coupling. The and lists include all applicable physics interfaces.

The default values depend on how the node is created.

•

If it is added from the ribbon (Windows users), contextual toolbar (macOS and Linux users), or context menu (all users), then the first physics interface of each type in the component is selected as the default.

•

If it is added automatically when the physics interface is chosen in the or window, then the two participating physics interfaces are selected.

You can also select from either list to uncouple the coupling from a physics interface. If the physics interface is removed from the , for example is deleted, then the list defaults to as there is nothing to couple to.


	If a physics interface is deleted and then added to the model again, then in order to reestablish the coupling, you need to choose the physics interface again from the lists. This is applicable to all multiphysics coupling nodes that would normally default to the once present physics interface. See Multiphysics Modeling Workflow in the COMSOL Multiphysics Reference Manual.