7th DOF - warping in single cell concrete box girder

Question:

I am analyzing a box girder using beam elements, and would like to evaluate the effects of warping, which it's my understanding, in addition to the increase in longitudinal stresses in the section, the warping of the section leads to transverse bending of the webs/flanges. I would have thought that the results from the 7th DOF output can be used to estimate these effects, but would question the validity of the Ssy(Mw) (kN/m2) diagram under selfweight, please comment.




Answer:
Hi,

Thanks for writing to us!
Once 7th DOF is turned on in the section properties, then program will calculate below properties additionally.


Then the program will calculate the Bi Moment (W) , Twisitng moment (Mt) , Warping moment (Mw).


After that program will calculate the stresses accordingly as shown in below snapshot.



In your case, as you are pointing out that Ssy is not appropriate, then check the twisting and warping moment behavior.

Your model is not attached, if possible attach your model file for our review. Also for your reference, please see the attached pdf where warping is described.


Regards,
Suman Dhara
Sr.Structural Engineer,
MIDAS, INDIA.
Creation date: 7/17/2018 10:25 PM (dklee@midasit.com)      Updated: 7/18/2018 7:55 AM (dklee@midasit.com)
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7DOF_Warping.pdf
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