Immovable

This restraint type sets all translational degrees of freedom to zero. It is the same for shells, beams and trusses. No reference geometry is used.

To access the immovable restraint, right-click on Fixtures in Simulation study tree and select Fixed Geometry. Under Standard, select Immovable (No translation).

For solids, you cannot access the Immovable (No translation) option. The Fixed Geometry restraint however is the same as the immovable restraint for solids.

The following table summarizes the attributes and input needed for this restraint:

Attribute Value
DOFs restrained for shell meshes 3 translations
DOFs restrained for beam and truss meshes 3 translations
3D symbol
Selectable entities Vertices, edges, faces and beam joints
Selectable reference entity N/A
Translations N/A
Rotations N/A

Example

The following example illustrates the difference between the Immovable and Fixed restraints for shells. Consider a thin plate that is simply supported at two opposite ends. A uniform normal pressure is applied to the shell.

The following schematic figures illustrate the deformed shape (blue dashed curve) of the shell when the Immovable and Fixed restraints are used.

Immovable: Finite rotations at the immovable edges (slope of the deflected shape is not zero). Fixed: No rotations at the fixed edges (slope of the deflected shape is zero).
Video: Shell Restrained with Immovable Restraint Video: Shell Restrained with Fixed Restraint