Define uniform or continuous bracing by specifying a distance along the beam that locates the starting point of the continuous bracing, specifying a second (longer) distance along the beam that locates the ending point of the continuous bracing, and then indicating whether the top, bottom, or both flanges are continuously braced over this length. Specify the distances as absolute (actual) distances or as relative distances, both measured from the I-end of the beam. A relative distance to a point is the absolute distance to that point divided by the length of the beam measured from the center-of-support to center-of-support.
Note: The Uniform Brace form also displays when a frame object is selected and the Design menu > {Steel Frame, Steel Joist} Design > Lateral Bracing command is used and the User Specified option is selected on the resulting Lateral Bracing form and the Specify Uniform Bracing button is clicked.
Relative Distance from End-I and Absolute Distance from End-I options. Indicate whether the specified distances will be relative or absolute from the I-end of the beam by selecting the appropriate option.
Braces -- Click the Add button to begin specifying the location of the uniform braces.
Start and End edit boxes. Input distances from the end-I to locate the starting point of the continuous bracing and a second (longer) distance along the beam to locate the ending point of the continuous bracing.
Type drop-down list. Choose the brace type. Top means only the top flange is braced, Bottom means only the bottom flange is braced, and All means both flanges are braced at that point.
Delete button. Click on a uniform brace specification and click this button to delete it.
Sort button. Click this button to sort the uniform braces based on the start locations.
Click the OK button and to return to the Composite Beam Overwrites form. Note that the No. Uniform Braces item is automatically updated by ETABS to reflect the specified uniform braces.
Access the Uniform Braces form as follows:
Select a beam or beams.
Select the Design menu > Composite Beam Design > View/Revise Overwrites command to access the Composite Beam Overwrites form
Click the Bracing (C) or Bracing tab.
Select Bracing Specified from the Bracing Condition drop-down list.
Double click the No. Uniform Braces cell.