Section 4.4 - goes through the torsional stress on a closed shape.
Section 4.6.2 - goes through the combined stresses from torsion and other loads on a closed shape.
There are also a few design examples.
Example 5.2 does what you are looking for I believe.
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
You can actually use the specification itself for this. I don't have it in front of me, but it's relatively straightforward. And as you must also check the combined torsion, flexure and shear.
It is arrogant and not the least bit helpful. True as it may be, it seems the only purpose is to make yourself look informed at the expense of the OP.
And torsion, in general, is NOT an easy problem. In tubular sections, it is fairly straightforward, but for almost any other shape it is quite involved.
Structural engineers have the added burden of taking many other factors into account. Is the section torsionally restrained? Is it compact? Is there additional loading perpendicular to the cross section? In both directions?
You mechanical's may be able to design a circular shaft to transfer torque and forget about it. We don't have that luxury.
Most structural engineers would tend to agree with frv and try to avoid torsion if at all possible. Sometimes that may not be possible so we seek a reference to help us out.
With torsion some strength of materials books dont have exactly what we need so we seek a bit more as the Op is doing.
I have a very interesting residence with a number of curved beams that are loaded on one side only. For example, I have a curved beam with a 32' span with a 2' offset to the side at midspan. There is a roof that cantilevers out from 6' to 8' on the outside of the beam with no structure on the other side.
This one is going to be fun. But it's going to require some study on my part.
I am still holding by my statement; however in fairness to the person who asked the question AISC has excellent reference material eventho to be able to use their naterial,it will require mental toughness as with any code reading.
May not be easy to get the reference Brezler Lin Scalzi "Design of Steel structures" but parts are really advanced strength of materials and theory is derived from first principles. I did use it on a number of occasions for torsion problems (fortunately for me not many)and it got me out of trouble.
I think it may be worth having a look at it if you can locate a copy.
Rather than start a new thread on beam torsion, I thought I'd follow with a similar request to this one. I've recently been asked to look at allowable twist in pre-stressed concrete I girders. I've gone through a couple of first principle derivations of possible strain states, but end up with unrealistic results.
I would appreciate it if anyone could point to some texts/papers/methods for evaluating the angle of twist at which cracking occurs.
torsion on closed sections is normally mainly a matter of addditional shear stress. Warping is negligible and axial forces are smal so both are generally ignored.
Any classical design textbook will give you a formula to calcualate the shear.
