When the Unidirectional tab is selected, the New Release Definition dialog is displayed.

To define a release, specify a label and the direction of the releases for the beginning and the end of the bar.

For displacements:

For rotations:

For example, to define a release for the bar in the previous image that makes this bar only a tension bar, define the release of the Ux+ direction at the beginning of the bar or the release of the Ux- direction at the end of the bar.