Out of Plane Tolerance of Bolted Plate

[wadavis]

I have a bolted T section to an existing web to pick up a shear load. The T section is to be shop fabricated and will consist of welded heavy plate, there is concern that the welded T will bow out the bolted plate and reduce the effectiveness of the shear connection. This is for the pricing phase of project so we are looking for a out of plane tolerance to supply to the fabricators, so that they can factor in QC requirements.

Are there any standards for out of plane tolerances on Shear / Slip Critical bolted connection?

wadavis
E.I.T.

 

[dhengr]

Wadavis:
I would use the AISC Manual or ASTM Specs. for mill tolerances on structural shapes as a good starting point. Also, there should be some fit-up tolerances for the flatness of the faying surfaces in slip critical joints/plates; at least a statement that the bolts must easily pull the plates up for a tight fit. I don’t think you will find any explicit tolerance for your exact detail. I don’t know what plane you are talking about, I only have a small single engine, 4 seater. In any case, the welds btwn. the flange pl. and the web pl. should tend to curl the flg. tips up toward the web, and this can easily be straightened or accounted for before welding. Any good fabricator should be able to account for this from experience. They just put the flg. pl. on a piece of .25" bar stock and gag the flg. tips down a bit before welding the web, if that needed. Additionally, the bolting will tend to flatten this curled bolting flg.

 

[wadavis]

ha, I see the problem with the term out of plane.

How about dimensional tolerances of the bolted T-section to a deep girder web. I've fished though CSA W59 and found the applicable clauses 5.3, 11.5.3.1 and 12.5.3.1. I think we are going to decide that the bolted T stiffener is stiffer than the girder web, so therefor must meet the dimensional tolerances of CSA W59 5.8(e) for deviation from flatness in the web.

I've dug through through the Specification for Structural Joints Using High-Strength Bolts from RCSC, I found nothing on deviation from flatness of the faying surfaces but some fit up tolerances would be great.

Thanks for the input, and in conclusion; a good machine shop know how to build it flat, we just need a way to tell them how flat.