Beam with End-Plates Too Short

[Cambridge99]

We have a large beam with end plates attached at each end that is too short by about 1/2". What is a common solution to this type of problem?
We are concerned about the bending load on the bolts. We are thinking about installing longer high strength bolts (longer bolts to keep the threads out of the shear plane) along with providing vertical shims. Will the shims ensure that there is no bending in the bolts? The beam and the columns can't be moved.

 

[JAE]

I would be tempted to weld a new 1/2" plate (with holes to match) onto the original plate and go from there.

 

[ToadJones]

I dont see an issue with 1/4" shim on each end.

 

[nutte]

With a 1/2" shim on one end, you'd have to reduce the shear capacity of the bolts. With a 1/4" shim on each end, you don't have to reduce the bolt's capacity. I second Toad's suggestion.

 

[EngJP]

Agree with the 1/4" shim each end. See AISC Specification Section J5 on fillers for more info on the shear reduction applicable if filler greater than 1/4".

 

[JAE]

But if you fully weld the 1/2" plate to the one end, it isn't a filler anymore...just an extension of the end plate - as though you had a thicker end plate so J5 filler provisions wouldn't even apply correct?

 

[nutte]

JAE, that's right.

 

[ToadJones]

You may find you need half of that 1/2" just to install the girder!

 

[dik]

Two 1/4" shims is likely less costly that field welding a 1/2" shim...

Dik

 

[connectegr]

Another vote for 1/4" shims at each end.

If a 1/2 fill is added to the endplate, then the plate must be welded to the endplate adequately to develop it's proportion of load.

http://www.FerrellEngineering.com

Providing fabrication and erection efficient structural design of connections. Consulting services for structural welding and bolting.

 

[msquared48]

Looks like your total length tolerance is about 1/16", 1/32" at each end. Does the 1/2" include this figure or not? If it does, you may need to go to 3/16" or 7/32" end plates.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[paddingtongreen]

I'd go 1/4" at one end, and 2 @ 1/16" and 1 @ 1/8" finger shims at the other. I wouldn't put plates at both ends in the original design unless it was going between columns before they were set.

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

 

[dik]

I'd be looking at 1/4" for both and use a swing press to install the second if necessary...

Dik