beams cracking torsion

[Ahmad Alhamad]

Hello,

I want to ask about cracking torsion when the member subjected to high axial force like tempreture
then the term under the square root will be minus, so then what is this mean ?
can i ignore torsion or the cracking torsion will be zero ?
in ETABS the program calculate Tcr zero, is this correct ?

 

[Lomarandil]

Yes, if you have sufficient axial tension, the critical tension could be zero (essentially, the tension alone is cracking your section).

In this case -- you cannot neglect torsion! You must design and detail closed stirrups adequate to take the torsional load without the benefit of the concrete.

Of course, check that the tension being generated by your model is correct (and not due to a boundary condition issue), and consider whether such a member justifies being pre-tensioned.



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The name is a long story -- just call me Lo.