Issue on torsion checks of round HSS using AISC 360-10https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/131022/issue-on-torsion-checks-of-round-hss-using-aisc-360-10Hi, I am analyzing a a frame of primarily individually defined round HSS sections, sections are defined as below. When the frame is post-processed with the AISC 360-10 code Method ASD, it appears that even when the code states TORSION 0, the programen-USTelligent Community 12RE: Issue on torsion checks of round HSS using AISC 360-10https://communities.bentley.com/thread/511604?ContentTypeID=1Sun, 17 Mar 2019 10:31:21 GMT6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:d6168fbc-aced-4f16-9132-d51b6f7f9a5eSon Nguyen<p>Hi Sye,</p> <p>How about&nbsp;round HSS which user defined as tapered tube, how the torsional constant (C) was calculated? AISC 360 have a user note to calculate this but i am not sure that it is used in Staad.Pro? I think Staad.Pro probably used incorrect&nbsp;<span>torsional constant for the user defined round HSS and this is the reason why the utilization ratio was so&nbsp;high.</span></p><div style="clear:both;"></div>RE: Issue on torsion checks of round HSS using AISC 360-10https://communities.bentley.com/thread/400066?ContentTypeID=1Thu, 26 Jan 2017 17:32:38 GMT6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:83561b0b-7b45-4990-81d6-93ed3b43a37aSye<p>For HSS sections, torsion check is automatically carried out. The design parameter TORSION only affects the torsion check for non-HSS sections. Regarding the second part of your question, the HSS torsional constant ( C ) is considered as per the values provided in AISC section tables. You may check the values by going to Tools &gt; Section Database &gt; Rolled Steel and choosing the appropriate section table ( like HSS Round) &nbsp;from within the AISC database (v14.1). Editing the value for the parameter C is possible too using the Edit Record option but ensure that you are using the correct value.</p><div style="clear:both;"></div>