Because design is an iterative process, after a {steel frame, concrete frame, composite beam, composite column, steel joist} design has been run, changes to the design section property assigned to one or more frames / joists may be necessary. ETABS allows multiple design iteration to be run without rerunning the analysis, which can save computing time.
Change a design section and redesign the structure without rerunning the analysis as follows:
Select the Analyze menu > Run Analysis command to analyze the model.
Select the Design menu > {Steel Frame, Concrete Frame, Composite Beam, Composite Column, Steel Joist} Design > Start Design/Check command to complete the initial design.
Select the Design menu > {Steel Frame, Concrete Frame, Composite Beam, Composite Column, Steel Joist} Design > Verify All Members Passed command to complete a stress/capacity check of the model. As necessary, use the Design menu > {Steel Frame, Concrete Frame, Composite Beam, Steel Joist} Design > Interactive Design command to evaluate the results.
Assuming that the design section for a selected member(s) must be changed, first select the member(s) to be changed. Then select the Design menu > {Steel Frame, Concrete Frame, Composite Beam, Composite Column, Steel Joist} Design > Change Design Section command to access the Select Sections form. Note that if no members are selected, the command will not be available.
Note: The Select Sections form also displays when the Sections button is clicked on the Interactive {Type} Design and Review form.
Choose the new section from the display list.
Rerun the design (Step 2) and repeat the stress/capacity check (Step 3). Repeat until all members pass the stress/capacity check.
If all members do not pass the stress/capacity check, change the design section (Steps 4 and 5). Rerun the design (Step 2), repeat the stress/capacity check (Steps 3), repeat until all members pass.
When design is acceptable, repeat Steps 1, 2 and 3 to verify that the frame members/joists have been designed using the correct forces and to verify that all members pass the stress/capacity check.
TIP: The Design menu > {Steel Frame, Concrete Frame, Composite Beam, Composite Column, Steel Joist} Design > Change Design Section command is useful when an auto select section is assigned to a beam. To control the section property used in the next analysis for a beam assigned an auto selection section property, use this command to set the design section property to a specified section.
See also