COMSOL 6.2 - Prescribed Displacement

Prescribed Displacement

The node adds a condition where the displacements are prescribed in one or more directions to the geometric entity (domain, boundary, edge, or point).

If a displacement is prescribed in one direction, this leaves the structure free to deform in the orthogonal directions.


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

Coordinate System Selection

The constraints are applied in the axis directions of the coordinate system selected in this section. You should only use a coordinate system that has fixed spatial directions.

Prescribed Displacement

For the displacement in each direction, select a setting from the list — , or . Select:

•

(the default) to leave the displacement component unconstrained.

•

to constrain the displacement component to a given value. Enter a scalar value for the component of the prescribed displacement u0.


	In versions prior to 6.2, you could chose to formulate the constraint in two ways: standard notation or general notation. Since it was rarely used, the general notation option is no longer supported. There are more natural ways of specifying identical constraints. If you have a model created in version 6.1 or earlier, where general notation was used, the settings for this option are visible, and are still functional. You should, however, consider to reformulate the constraints, since the general notation may no longer be supported in future versions. For reference, the documentation for the general notation is provided below: You can specify the displacements using a general notation that includes any linear combination of displacement components. For example, for 2D components, use the relationship For H matrix H select Isotropic, Diagonal, Symmetric, or Full 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.