RISA V10.0 Sway Flags

Question

RISA V10.0 Sway Flags

JoshH726 (Structural)

(OP)

28 Jun 12 11:40

What has happened to the sway flag designation in the Hot Rolled Steel Design Parameters? It appears the only way to assign them is through the Modify Member command or by clicking individual members. Previous versions allowed sway to be assigned directly through the Hot Rolled Steel Design Parameter spreadsheet.

JoshPlumSE (Structural) · Answer 1 · 2012-07-02 10:56:49

Jhost -

The Sway Flags are still there. But, it depends on which code you are using. If you are using the newer steel codes (AISC 13th and 14th editions) we hide these sway flags because they are no longer used for those codes. I suppose they could still affect the "approximate K" value feature. But, the 13th and 14th editions are really built around the Direct Analysis Method and the assumption that you will be using a K value of 1.0.

Josh

JoshH726 (Structural) · Answer 2 · 2012-07-02 13:27:29

Josh, thanks for the reply. A follow up question regarding the K-values using DAM, if I would approximate a K-value not equal to 1, but have the Adjust Stiffness Global Parameter set to "yes (either iterative or tau=1), will RISA use the approximated K-value, or will RISA override that value and use 1 for the DAM?

JoshPlumSE (Structural) · Answer 3 · 2012-07-02 17:10:46

RISA will use whatever K value you entered, even if you are using the Direct Analysis Method.

Some might say that this is a bit inconsistent with the direct analysis provisions. But, there are times where you might want to use the K value to adjust the unbraced length rather than adjusting the unbraced length directly. So, using the user's K value gives him/her a bit more control over the program's code checks.

Come Join Us!

Posting Guidelines

RISA V10.0 Sway Flags