Dears,
Reference to below example, the moment is positive reached the maximum 2000 and then go down to -1600.
But According to STAAD, it is on the opposite direction.
Can someone kindly explain the reason?
This is our sign convention for MZ: A positive moment will mean a moment causing tension at the top of the member. Conversely, a negative moment will cause tension at the bottom of the member. The top of a member is defined as the side towards positive local y-axis.
See this for more: C:\Program Files\Bentley\Engineering\STAAD.Pro CONNECT Edition\Help\GUID-389C95C2-0C22-4FC8-8D1C-05A5C654BBA1.html
Answer Verified By: Rabih Elias
The diagram of bending moment in Staad is coherent to his convention.
With this convention, it will be easier for concrete design --> put steel in tension fiber
Great, now i understood, thank you very much
Thanks a lot
I have a model of a large structure, analysis is complete. If I go into post processing mode, and click on a particular member, I get a dialog box with several tabs. One is labeled Shear Bending. If I select this tab, I am able to se shear and bending moments on the selected member. I am observing the Mz values at the end of a member. (This is major axis bending for a beam. Then, when I right-click on the screen I get a dialog where I can select various output tables. I can select the table for member end forces. If I look into that table, at the Mz values at the end of the same member, I find that the sign has been changed for all the Mz values. Apparently, from one output screen to the other, a sign convention has been changed. Can someone explain this change, and advise which sign convention is used in each location?
thanks in advance.