Stiffeners in torsion
Stiffeners in torsion
(OP)
Could someone direct me to a design example for a pair of stiffeners [full depth] on a beam subjected to torsion? Specifically, I am trying to check the weld of the stiffeners to the flange and the web. Thanks in advance.






RE: Stiffeners in torsion
What is your situation? Beam size, stiffener thickness, weld size, beam span, beam support, load application location and type?
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RE: Stiffeners in torsion
RE: Stiffeners in torsion
RE: Stiffeners in torsion
RE: Stiffeners in torsion
If the stiffeners are at the load application points, helping to resist web crippling, the only calc that comes to mind is to size the vertical welds for transferring all the concentrated load into the beam's web.
Other than that, just use a weld that looks right based on thickness of joined parts.
tg
RE: Stiffeners in torsion
1. convert the torsion into a force couple at the centerlines of the two flanges.
2. divide this force by the total length of weld between the top of the two stiffeners (1 each side) and the top flange.
3. Choose a fillet weld appropriate for the calculated k/in and apply it throughout.
RE: Stiffeners in torsion
1) web be crushed or bent due to vertical load
2) web being bent due to eccentricity (ie moment through the web)
The moment is what I believe we are really looking to resist. So couldn’t you treat that section with the welded stiffener as a T section and find out your maximum allowable moment through the T?
RE: Stiffeners in torsion
Please let us know where along the length the stiffeners are, and how you plan on providing torsional fixity at the beam ends.
Also, how exactly is the 65kip load is applied?
tg
RE: Stiffeners in torsion
RE: Stiffeners in torsion
then I would do 2 calcs:
1 - per my previous post, sizing the vertical weld for the full 65 kip load. I guess it's roughly 65k / 10 inches = 6.5 k/inch, into the 2 fillet welds that connect the bearing stiffener to the beam web. You may have to do a groove plus fillet weld. Asd you may know, bearing stiffeners have this sole function - to take a direct load from the flange and to carry it into the beam's web.
2- Check web crippling including the contribution of the stiffener, so a certain allowable stress (from your design code) over a portion of the web (including fillet) plus the cross sectional area of the stiffener, as if the stiffener is also a web that is resisting a concentrated load.
The effective area will be a (capital)T shape, unless your applied load bears wide enough to engage the stiffener on the opposite side of the web, in which case you'll use a t (cruciform) shape.
I hope my chicken scratch is clear enough...
tg