Preventing Torsion

[DHKpeWI]

I am designing a bent C channel spanning 14'-0". The channel is loaded by hat channels on the bottom flange. See attached drawing. Since I am not loading the C channel through the shear center the loading will create torsion in the C. I think I can resist the torsion by welding the hat channel to the C. What do you think?

Thanks

DHK

 

[csd72]

structural engineering is sometimes more an art than a science.

There are not answers to everything.

 

[DHKpeWI]

Thanks to everyone for your insights.

I ran a calculation for the warping torsion on the channel assuming the hat channels do not resist the torsion. In this application the C channel is restrained against rotation at the ends. For the load and span used here the warping stresses are larger than the yield stress of the steel (AISC Design Guide #9). I added a stiffener welded to the top of the hat channel and the web and flange of the C channel to retrain the torsion.

God Bless.

DHK

 

[paddingtongreen]

Oops. I didn't finish on my experiment. When I folded the flange out, I realized that the outside edges would try to get back to their original length reversing the curvature.

Michael.
Timing has a lot to do with the outcome of a rain dance.