Weld Strength of Cantilever Beam 2

[mark4lte]

Hey guys,

I have a question that I'm sure most of you can answer without even thinking about it. I have no structural experience and no mentor at my place of business (believe it or not). It seems most universities cover weld strength in their structural steel design course however, mine did not.

My question is how to determine the capacity of a beam to beam connection (see attached drawing) with the top and bottom flanges welded together? This little beam is going to support a pipe weighing a little over 2200-lb. The beam itself is adequate but I'm not sure how to analyze the strength of these welds. For simplicities sake assume the load is acting vertically at the far end of the beam.

I would appreciate if someone could explain this or upload a hand calculation for this.

Thanks a lot!

 

[desertfox]

Hi

This site might help

http://www.gowelding.com/calcs/c7.html

I don't think it's a very good way to design and connect the beams as shown in the diagram, why can't you just extend the cantilever beam coming from the wall to support the pipe.
If you need another piece of beam running at right angles to the cantilever, then it would be better to allow the web of one beam to butt upto the other beam Webb, this can be achieved by cutting off the flanges of one beam for an approximate length of half a beam section width and allowing the web of this beam to pass under the flanges of the intersecting beam.
This will allow the supporting beam to be welded to the other beam at both flanges for the whole width and the whole web depth on both sides.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[kingnero]

Also, don't forget to check the existing W10 as you add a lot of torsion to it.

 

[racookpe1978]

Any structure supporting a 2200 pound load overhead should be checked, if not completely designed, by a qualified engineer. There is always time and money to check things - after they fail.

Be safe.

 

[gtaw]

The top and bottom flanges of the stub beam form a moment couple, the top flange being loaded in tension, the bottom flange loaded in compression. The shear is typically sustained by the beam web.

A single plate shear tab can be welded to supporting beam. A two bolt connection will provide a means of locating and securing the stub beam while the top and bottom flanges are welded.

The top and bottom flanges of the stub beam can be CJP groove welds as shown in the sketch, but backing must be employed if the welds are to be considered prequalified per AWS. Likewise, the allowable unit stress should be in accordance with AWS D1.1 and AISC Steel Construction Manual.

As per one of the responses, one must check the supporting beam for to verify it can sustain the torque being applied by the stub beam.

Best regards - Al

 

[MikeHalloran]

As noted, you need to check the W10's deflection from the pipe weight and from the associated torsion.
I sections and W sections are remarkably limber in torsion. That's not always a good thing.


Mike Halloran
Pembroke Pines, FL, USA