aisc lrfd punched holes
aisc lrfd punched holes
(OP)
If you have punched holes on connection, you add the diameter by 1/8" right? Where can I find that on the manual? I cant seem to find it.
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
Download nowINTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: aisc lrfd punched holes
RE: aisc lrfd punched holes
RE: aisc lrfd punched holes
RE: aisc lrfd punched holes
D3.2, Page 16.1-27 in the 13th Ed.
Just in case you're looking at an older Manual,
B2, Page 16.1-10 in the 3rd Ed. LRFD
B2, Page 6-34 in the 2nd Ed. LRFD
LOL, and while we're at it (drumroll):
B2, Page 5-33 in the 1989 ASD
RE: aisc lrfd punched holes
RE: aisc lrfd punched holes
That being the case, the bolt hole should be taken as 1/8" greater than the nominal bolt diameter.
RE: aisc lrfd punched holes
"One of the critical details in a bolted or riveted structure is the fastener hole. Punching the holes causes strain aging and work hardening of the material around the hole."
and
"To eliminate these points of potential crack initiation, holes should be either drilled or subpunced and then reamed in order to eliminate small surface cracks and work hardened material if brittle fracture is possible under service conditions."
Under division II of AASHTO's Standard Specifications, Article 11.4.8.1 limits the thickness of material that can be punched.
RE: aisc lrfd punched holes
RE: aisc lrfd punched holes
For example, if you have a standard hole, when checking tension rupture, shear rupture, or block shear, you'd use the bolt diamter + 1/8.
If you have an oversided hole, you'd have the bolt diamter + 1/8 + 1/16.
RE: aisc lrfd punched holes
RE: aisc lrfd punched holes
My old college textbook (McCormack, 2nd Ed.) says that the 1/16" is to account for the damage to the holes during the punching process. McCormack goes on to say that it is unnecessary to add/subtract the 1/16" for drilled holes.
The AISC code has apparently decided to not differentiate between the two methods, and to be conservative for drilled holes.
RE: aisc lrfd punched holes
RE: aisc lrfd punched holes
I would guess that AISC makes no distinction because EOR types don't know what fabricator will be used, etc., so he might not know if it will be drilled or punched. Those limit states don't control very often, so the extra 1/16 doesn't hurt much.
I think bridge folks might be closer to the process so might know more about what'll be done, but I could be wrong, not being a bridge guy.
For AISC, the part that screws everybody up is how the 1/16 only applies to some limit states. Tear-out does sometimes control for close bolt spacing, so I guess they decided to not further simplify the situation by using the extra 1/16 there too. Then again, I'm just guessing.