propper welding of top and bottom plates to i beam
propper welding of top and bottom plates to i beam
(OP)
I have a w27x114lb x 240"l I-beam with a 12"w x 240"l 1"t plate on top and a 12"w x 240"l x .625"t plate on bottom. The reason for the plates was to achieve the section modulus needed and to meet required existing heights and safety factor. What I am unsure of is appropriate welding practice to simulate these plates being part of the I-beam. We were originally going to bevel and seam weld all interface edges all around. I am worried about tempering the I-beam when introducing that much heat. So how much of a weld do I need. Can it be stitch welded 1 foot every foot or some other variant?
Thanks for the impute
Dallas
Thanks for the impute
Dallas
only in a steel mill.





RE: propper welding of top and bottom plates to i beam
In a very old reference called "Design of structural steel work"
plates that are welded onto the top and bottom of a rolled beam can have space welding the spacing being a maximum 16 times the thickness of the thinner part in compression, in no case more than 300mm and 24 times the thickness of the thinner part in tension. Also the stiffening plates are not required to go beyond any point at which the applied bending moment falls below the bending strength of the rolled beam.
If the plates are automatic welded then the welds are usually continuous.
You really need the updated specs for this project but at least you know that the plates can be stitch welded.
desertfox
RE: propper welding of top and bottom plates to i beam
RE: propper welding of top and bottom plates to i beam
desertfox, thanks for the reply just ordered the most recent version of that book.
thanks for the help
Dallas
RE: propper welding of top and bottom plates to i beam
your welcome.
RE: propper welding of top and bottom plates to i beam
ht
RE: propper welding of top and bottom plates to i beam
RE: propper welding of top and bottom plates to i beam
For fatigue, consider using continuous welds rather than stitch welds.
RE: propper welding of top and bottom plates to i beam
would adding this much heat into the beam effectively temper the steel thus making it brittle and more prone to fatigue failure
RE: propper welding of top and bottom plates to i beam
RE: propper welding of top and bottom plates to i beam
As you're dealing with an overhead crane might it be advisable to talk to a crane manufacturer?
I am not sure that beams with strengthing plates are permissible for overhead crane construction.
Your strengthing plates top and bottom will increase the static strength of the beams but you increase the chance of fatigue failure of the doubler plate welds by only stitch welding them.
Have a look at this link:-
http:/
it shows a doubler plate welded on a beam and gives classifications to the weld type and geometry in relation to possible fatigue failure.
I beams are completely fabricated by welding plates together so I don't see a problem welding doubler plates continiously.
desertfox
RE: propper welding of top and bottom plates to i beam
2-1.4.2 Girders (for new)
.... conform to the design parameters as specified, in CMAA Specification No. 70 or AISE Technical Report No. 6.
2-1.4.3 Modifications
Cranes may be modified or rerated provided such modifications and the supporting structure are analyzed thoroughly and approved by a qualified person or manufacturer of cranes.
and look at posts
http://www
RE: propper welding of top and bottom plates to i beam
www.PeirceEngineering.com
RE: propper welding of top and bottom plates to i beam