Prescribed Displacement/Rotation
The Prescribed Displacement/Rotation node adds an edge (3D), boundary (2D), or point (2D and 3D) condition where the displacements and rotations are prescribed in one or more directions.
Coordinate System Selection
Specify the coordinate system to use for specifying the prescribed displacement/rotation. See the section Coordinate System Selection for Edge Load.
Prescribed Displacement
Select one or all of the Prescribed in x direction, Prescribed in y direction, and for 3D models, Prescribed in z direction check boxes. Then enter a value or expression for u0, v0, and for 3D models, w0.
Prescribed Rotation
For 2D models, to define a prescribed rotation select the Prescribed in out of plane direction check box and enter a value or expression for θ0z.
Free (the default) to leave the rotations unconstrained.
Rotation to activate a prescribed rotation. Enter values or expressions for the prescribed rotation vector θ. When the study is geometrically linear, you directly prescribe the individual components of the rotation vector.Under For geometric linearity, select one or several of the Free rotation around x direction, Free rotation around y direction, and Free rotation around z direction check boxes to remove the constraint for the corresponding rotation component. If unchecked, the rotations are constrained to either the input value or to the default zero rotation. The status of the check boxes has no effect when geometric nonlinearity is activated under the study settings. This is because the constraints put on different rotation components are not independent of each other in the case of finite rotations. Here, θ should be interpreted as a rotation vector in the given coordinate system. The norm of the vector is the angle of rotation, and the orientation of the axis of rotation is given by the vector components.
Constraint Settings
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box.
In the COMSOL Multiphysics Reference Manual:
You can add a Harmonic Perturbation subnode for specifying a harmonic variation of the values of the prescribed displacements in a frequency domain analysis of perturbation type.
Location in User Interface
Context Menus
Ribbon
Physics tab with Beam or Pipe Mechanics selected: