Use this procedure to change the type of one or more structural members. Because beams, braces, and columns are sub-types of a single structural member object, you can change a beam to a brace, a column to beam, or a brace to a beam.
Select the structural members to change, and double-click one of them.
On the Properties palette, expand Basic, and expand General.
Select a setting for Member type: Beam, Brace, or Column.