The motions of a structure can be restricted by the deactivation of one or more of its degrees of freedom.
To add a Deactivated Freedoms:
Select the Hydrodynamic Response object in the tree view.
Right-click the Hydrodynamic Response object and select Insert > Deactivated Freedoms, or click the Deactivated Freedoms icon in the Analysis toolbar.
Deactivated Freedoms objects can be added to Stability Analyses and Time Response Analyses. A Deactivated Freedoms object which has been added to a Stability Analysis can be propagated to any downstream Time Response Analyses.
Under Freedom Deactivation, select a Structure from the drop-down menu of structures included in the analysis. Then select up to six Deactivated Freedoms. A graphical representation of the unrestricted freedoms will be displayed at the structure's center of gravity. In the example below, the motion of the selected structure has been restricted to the horizontal (XY) plane.
Note: If all translational degrees of freedom are to be deactivated, it is preferrable to use a Joint connection to restrict the motion of the structure.