Different moment beam and column in etabs and robot structural, help me !

[Anonymous]

hi everyone,

I have question about moment between Rsap and Etabs:

+ when i run the same model but the moment of beam and column at point beam-column if different. the result of RSAP is higher 15-20 % at this point.

can you explain to me how to error in my model.

regard

[Artur.Kosakowski · Accepted solution]

I hope that somebody having ETABS and RSA will be able to compare both models but in the meantime I would suggest making the following tests to see where the difference originates from:

1. Check the sum of vertical and horizontal reactions

2. Delete meshes and see if the results are the same

3. Delete offsets and check if this is the reason

4. Delete all but the bottom level and check again

5. Delete lines of frames one by one 

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[Anonymous]

thanks for your help, 

I find problem ( the result of Rsap similar ETabs 9.7... Etabs 2015 hae different result.. )

Can i ask you one question the moment of Beam when I use spectral case between etabs and Robot I get the result similar but the robot is - value, the etabs is + value... both them use CQC combination,

can you explain about problem ! thank you so much Artur. Kosakowski

[Anonymous]

Sorry I sent you this files

[Artur.Kosakowski]

If the absolute values are the same and the difference is in signs then I assume that both programs use different sign convention for internal forces for bars. In RSA it is as described here:

http://help.autodesk.com/cloudhelp/2016/ENU/RSAPRO-UsersGuide/files/GUID-D1195F2E-6310-4DF6-BE1E-DCC...

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.