Selecting the Assign- Column-Unbraced Length command causes the Assign Unbraced Length dialog box to be displayed. From this dialog the engineer can specify on a column-by-column basis whether to override the automatically calculated unbraced lengths. These can be assigned for each of the two axial buckling axes (Major and Minor) and the bending compression flange (out-of-plane from bending axis) for lateral torsional buckling consideration.

By assigning Global to any of the column axes for consideration of unbraced length the program will automatically calculated the values as described in section 3.1.8. Assigning a specific value to an axis the program will use that value for the appropriate strength calculation. Assigning a specific value to an axis the program will use that value for the appropriate strength calculation for every segment of the column that is checked.

To view which columns have an assigned unbraced length, select unbraced length from the frame column tab in the View-Members Dialog.