How do I use the Lateral and Strut restraints options?

Environment

Not environment-specific

Question:

Answer:

The lateral restraints and Strut restraint options are found in the member Properties. This dialog can be opened by right-clicking on a member and choosing the Edit option, or by double-clicking on a member. The values entered alter the effective length values used in the buckling and other checks during the design process. But what do they relate to and what happens if they're edited?

Note that you can now also use the Review View > Show/Alter State "Restraints" command to review and edit restraints graphically for multiple members. Making edits using this automatically updates the restraint properties discussed below. For more on this see the related links - the Show/Alter State - Restraints Video and associated Help Topic. See also the help topics on steel beam and column restraints.

The dialog

The below images show the default Lateral and Strut Restraint property pages. If you wish for a floor or member not to restrain the member being edited, you can tick the option Face A override or Face C override override that face of the member. You can then untick the appropriate restraint option next to it. If you wish for a different effective length to be considered, you can adjust the appropriate effective length factor, defaulted to 1 below.

Face A or Face C?

To determine which face is Face A and which is Face C, turn on the Member > Direction in Scene Content. This will display a pink arrow running along the members in the scene view, and Face A is the face with the arrow running along it.

Strut restraints are usually members which are coming into the major or minor axis (blue arrows) and contribute to the compression buckling checks.

Lateral restraints are the members that restrain the flanges and contribute to the lateral torsional buckling checks (green arrows).