Frame Fixity
To change or review the member end fixities it is recommended that you display the end fixity on screen:
The default element fixity for lateral beams and columns is fixed in all degrees of freedom (Major, Minor, Torsion). Gravity steel beams are always pinned, though concrete gravity beams can be fixed. The default for braces is to be pinned in all directions.
The fixed condition is indicated by an "X" while a pinned end condition is indicated with an "O". When all fixity conditions are shown simultaneously, for the left or top end of a member, the first character (reading left to right) is for the major axis, the second is for the minor axis and the third is for the torsion axis. For the bottom or right end of the member the opposite order applies.
If the Frame numbers are interfering with the end fixity symbols then turn off the frame numbers by again selecting Options – Show Property – Frame Number.
- Select the Elevation View of the Frame on Line A.
- Select .
The Assign Frame Column Fixity dialog box should appear. It has two sets of option buttons that give you the choice of setting the column ends to fixed or pinned. One set is for the top of the column and the other for the bottom.
- Set Major and Minor Axes of the Bottom to Pinned.
- Click [Single].
- Select the third level columns (the bottom level of steel). Notice that the fixity display changes.
- Repeat for the braced frame on Grid F.
To change the Frame Fixity for the ends of the beams for the frame on Grid F only:
- Select .
- Set Major and Minor Axes of the Left and Right ends to Pinned.
- Click [Fence].
- Fence the entire elevation.
- Select .
This completes the layout of the frames. Now you can assign the fixity for all concrete beams.