Prescribed Displacement (Thin Layer)

The node adds a condition where the displacements are prescribed in one or more directions to the boundary.

If a displacement is prescribed in only one direction, this leaves the thin layer free to deform in the other directions.

You can also define more general displacements as a linear combination of the displacements in each direction, see Prescribed Displacement.


	If a zero displacement is applied in all directions, this is the same as a Fixed Constraint (Thin Layer).


	For details, see Prescribed Displacements, Velocities, and Accelerations.

Coordinate System Selection

The is selected by default. The list contains all applicable coordinate systems in the model. Prescribed displacements and rotations are specified along the axes of this coordinate system.

Prescribed Displacement

Select a — or .

Standard Notation

To define the displacements individually, click the button.

Select one or all of the ,, check boxes. Then enter a value or expression for the corresponding inputs u0x, u0y, and u0z. For axisymmetric components, select one or both of the and check boxes. Then enter a value or expression for u0 and w0. When twist is included in 2D axisymmetry, the circumferential displacement can also be prescribed.

General Notation

In 3D, 2D, or 2D axisymmetry, click to specify the displacements using a general notation that includes any linear combination of displacement components. For example, for 2D components, use the relationship

For the H matrix H select , , , or and then enter values as needed in the field or matrix. Enter values or expressions for the R vector R.

For example, to achieve the condition u = v, use the settings

which force the domain to move only diagonally in the xy-plane.

Constraint Settings

To display this section, click the button (

) and select in the dialog box. For more information about this section, see Constraint Settings in the COMSOL Multiphysics Reference Manual.

Excluded Points

To display these sections, click the button (

) and select in the dialog box. For more information about these sections, see Excluded Surfaces, Excluded Edges, and Excluded Points in the COMSOL Multiphysics Reference Manual.

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Modeling Thin Layers in the Structural Mechanics Modeling chapter.

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Theory for Thin Layers in the Structural Mechanics Theory chapter.

Location in User Interface

Context Menus

Ribbon

Physics tab with node selected in the model tree: