After the Vibration - SCI Publication P354 command has been invoked and the beams all classified according to types of bays, the target cursor is available to select any beam. When a beam is selected, the bay of which it is a part is analyzed as explained here.

For "Irregular" bays (gray) no vibration analysis is performed, as that analysis would be meaningless (and probably erroneous). As explained previously, no analysis is performed because, according to the research, no analysis is necessary; those bays do not, in real floors, exhibit vibration problems. For a unique beam in an area of irregular, non-orthogonal framing the SCI P354 methodology is not appropriate at all, nor, according to research, is it even necessary (except in very rare circumstances); any vibrations will dissipate into the surrounding framing before it is perceptible to a person standing near the beam under consideration. When an "Irregular" bay member is selected for analysis, a message is given indicating that no analysis can be performed on that bay.

For "Perfect" bays (blue), those in which the bay "perfectly" matches the Publication bays, the vibration analysis is performed directly by launching FloorVibeUK with all pertinent size and geometry data passed from RAM Steel to FloorVibeUK.

For "Imperfect" bays (yellow), those bays that exhibit some characteristic but have some deviation from the "Perfect" bay, the vibration analysis cannot be performed until after the user has "idealized" the bay by indicating how those deviations should be appropriately approximated as a "Perfect" bay. To accommodate this, a dialog box appears showing the framing of the bay selected and the corresponding idealized bay. Edit boxes and controls in the dialog box contain the data defining the bay. This data is filled in as much as possible by the program; where there is ambiguity or where there are significant variations from the configuration of a "Perfect" bay, the values are left blank. All entered values should be verified and any missing data supplied by the user. When all of the necessary data has been entered, selecting OK will cause the FloorVibeUK program to be launched with the data as specified. The FloorVibeUK program will indicate that this is an approximation of the actual configuration of the bay in the RAM Structural System, since it is an "idealization" of the actual bay.

To assist the user in determining the data to enter into the Define Idealized Framing dialog box, the reasons that the bay was not considered a Perfect bay are listed in the "Bay Imperfections" section. The beam and girder sizes are shown on the Actual Framing graphic; by selecting the Show Length button the beam and girder lengths will be shown instead.

The Floor Width and Floor Length values represent the distances between slab edges or bays of significantly different framing, and physically represent the extent of the floor in each direction that may vibrate as a unit. When the bay is a "Perfect" bay the program determines these values automatically by determining the extent of additional "Perfect" bays in each direction and summing up these distances. In addition, Floor Width and Floor Length boundaries are also established by any of the following: slab edges, walls, the edge of any bay whose length is less than one half of that of the selected bay, or the edge of any bay with a change in the direction of joist framing. This approach may be conservative as it will ignore the contribution of any "Imperfect" bays to these values (which in some cases could be included in the values). See P354 for more information on the definition of these values. If the bay selected for analysis is not a "Perfect" bay, these values are not calculated automatically, but must be determined and entered by the user.

Note that although, as explained previously, the need to analyze an area of irregular framing is very rare, it can be done by invoking the FloorVibeUK program independently of RAM Steel and entering the data as an idealized bay. In this way even framing that RAM Steel identifies as Irregular can be analyzed for vibration if it can be approximated within the guidelines of SCI P354.