Composite Beam Action?
Composite Beam Action?
(OP)
I'm looking for feedback on the analysis/common practices for reinforcing an existing W-flange beam. I' reviewing an existing W-flange beam supporting some mechanical equipment. The owner wants to add equipment to the beam doubling the load on the existing beam and over stressing the beam. I would like to reinforce the beam with a WT section welded to the bottom flange of the existing W-flange beam. The existing load cannot be removed during the installation of the WT. My question is this: Do I treat the design of the built-up section similar to a composite steel/concrete section (simplified: Moment_existing/Section_existing + Moment_additional/Section_built-up)?






RE: Composite Beam Action?
The sum of the new stress plus the old stress must be below allowable. ( Here I go still thinking in ASD!!)
For full disclosure, this is a point of disbute in our office.
Is there anyway to shore the beam up from below to relieve the existing stress on the beam while the new WT section is added? Then the built up section would be effective (in my mind) for the whole load when the shoring is removed.
JMHO.
RE: Composite Beam Action?
Some other thoughts:
Is there anyway you can cut the tributary area of the beams to lessen the load instead of installing a large WT section. Also, can you add studs to this beam? Maybe do some studs with a smaller WT section.
Just some ideas.
Is it failing in bending and shear?
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
RE: Composite Beam Action?
RE: Composite Beam Action?
RE: Composite Beam Action?
RE: Composite Beam Action?
RE: Composite Beam Action?
There are a large number of ways to strengthen such a frame. Anything from changing fixity condtions at the ends of the beam to adding kickers to kingposting the beam may work depending on the actual geometry and loads, but if you have determined that welding a WT to the bottom flange is the best bang for your buck then good luck with it.
kslee
I don't see the benifit of adding to the sides of the web. You would need to add far more steel by weight to get the same increase in bending strength and require a much longer length of field welding.
RE: Composite Beam Action?
thread507-221554: Steel Built-Up Beam
Check it out.
Read through the thread, too, it will be helpful
RE: Composite Beam Action?
I have used a small but heavy W shape to do the same job.
RE: Composite Beam Action?