Steel Beam Layout - Lower Levels
Steel beams, like concrete beams, must be modeled to have two supports. Beams with cantilevers are modeled as simple-span beams first, then the cantilevers are added to the end. Do not attempt to add a long beam from the tip of the cantilever to the other end of the beam as it will cross the supporting beam or column which is not allowed. When you have indeterminate systems, like two cantilevers meeting at a point, simplifications may have to be made. To begin laying out beams:
- Select the 2nd floor type by using the drop down menu in to toolbar.
- Select .
- Change the shape to Channel Note: In order for a beam to be designed as a composite beam, it not only needs to be defined as a composite section, but it also needs to have a composite deck on top of it for the entire beam length. If the beam is covered with noncomposite deck (or no deck at all) then it will always get designed as noncomposite.
- Click [Single].
- Add steel beams connecting the new steel columns together.
We need a pair of beams to finish the framing of the open atrium. To add them:
- Select .
There are many options for adding beams off-grid. Often it is a matter of adding a new beam parallel to an existing beam with some specified offset. This can be done even if the new beam is in a different bay. In this case the beams will be added from a column to a beam.
- Set the Graphics mode to Column-To-Beam
- Set the angle to 90. This will allow us to add new beams from a selected column to the closest beam that is 90 degrees (global) from the column.
- Click [Add].
- With the target cursor, select the column at R1-S2 and then click to the north of that column. Repeat for the column at R5-S2.
- Switch to the 3rd floor type.
- Repeat the above steps for all of the columns on grid line S3.
That completes the layout of beams on the 2nd level, but there is some more work to do on the other level types.