Member Code Check - Standard Provisions

You will now perform a code check on all lateral members using the load combinations you selected previously. To perform a code check:

Select Process > Member Code Check.

A progress bar will keep you informed of the progress of the code check. Because the program needs to check each unbraced segment of each member for each load combination, the process can take several minutes.

When the code check is complete, the lateral system of the model will appear color coded to indicate to what degree the members are stressed. A color scale correlates the colors to the interaction values of the members. The display of each member is based on the controlling Interaction Equation from all the selected load combinations.

Click [Show Values] to display the interaction equation values on screen.
Note: An interaction value of "-1" indicates that the member fails some prescriptive limitation (e.g. KL/r > 200).

The View/Update command can be used to interactively modify individual member sizes to improve the design.

Select Process > Member View/Update.
With the cursor, select one of the red beams in the braced frames at the roof level.

The Beam View/Update dialog box should appear. In the lower left hand corner is an indication of the maximum interaction equation or design warning. In this case, the bottom flange of the beam is completely unbraced. When there is compression in the member it will thus fail the KL/r limit of 200 (US codes) or it will fail the L/r limit of 300 when the member is in tension. The stoplight in the box will be red to indicate when the member has a design warning.

Click [Close].
Select one of the Moment Frame beams.
This beam should pass and the interaction value will be listed at the bottom.
To see the details of the design Click [View Results].

The Member Code Check Report should come up. Review the report. In particular, take note of the unbraced length for bending - Y-axis value.. A beam is typically broken into several unbraced segments, each with a different unbraced length. The single segment that yields the highest interaction ratio is the one segment that gets reported on the design report.

Note: When a member fails a prescriptive limit, the reports results are for the first combo that causes the problem. The reported forces are not necessarily the critical forces.

For more information on the design performed in this check, refer to the technical portion of the RAM Frame Manual.

Click to exit the report.
Select a different section from the Beam Size list box.
Click [Analyze]. The interaction equation and signal light will be updated to reflect the results of the analysis.
Click [Close] to exit without saving the modified design.(Click [Update Database] if you want to make the change permanent.)

If you modify any member size using the view/update command, the color of the member will change to indicate the new level of stress. As with View/Update in Analysis Mode, a second member can be selected without closing the View/Update dialog box.

Note: The program uses the member forces from the original analysis, but uses the section properties of the currently selected size when a redesign is performed. Once sizes have been changed the analysis of the model is no longer technically valid. Notice that the status indicator light on the status bar in the lower right corner has turned yellow to indicate that you should view all results with caution as they no longer represent the analysis of the current member sizes in the database. Whenever member sizes are changed, the analysis should be re-run to insure accuracy. This applies to all of the View/Update commands in RAM Frame.

To rerun the analysis and verify the new sizes:

Select Mode > Analysis > Load Cases.
Select Process > Analyze.
When the Analyze dialog box opens, make sure that all of load cases are selected and Click [OK].
Select Mode > Steel > Standard Provisions.
If you want to skip the slenderness limit checks this time, select Criteria > Axial Slenderness Limits and turn off both parameters.
Select Process > Member Code Check.

The new code check results should be indicated on screen. By working through a few cycles of this process, you can quickly converge on an efficient working design.