Trying to simulate a clip critical connection with a bearing condition
Trying to simulate a clip critical connection with a bearing condition
(OP)
Hey folks,
Is it legitimate to 'undersize' bolt holes (not actually undersize, but match drill the connections for a snug fit) so that a bolted connection resists forces like bearing, but since it is somewhat snug, it moves a relatively small amount - hence behaving more like a slip critical connection??
I know all the bolts won't be perfectly snug, but certainly our effort would be to minimize the slop in the connection bolt holes.
We're basically trying to do this to minimize the number of bolts required to get something close to a slip critical connection as the proper number of bolts will cause clash problem with other items.
Thanks for any thoughts.
DRW
Is it legitimate to 'undersize' bolt holes (not actually undersize, but match drill the connections for a snug fit) so that a bolted connection resists forces like bearing, but since it is somewhat snug, it moves a relatively small amount - hence behaving more like a slip critical connection??
I know all the bolts won't be perfectly snug, but certainly our effort would be to minimize the slop in the connection bolt holes.
We're basically trying to do this to minimize the number of bolts required to get something close to a slip critical connection as the proper number of bolts will cause clash problem with other items.
Thanks for any thoughts.
DRW





RE: Trying to simulate a clip critical connection with a bearing condition
First thing to evaluate is if you need a slip critical connection in the first place.
Dik
RE: Trying to simulate a clip critical connection with a bearing condition
and no... welding is not an option...
so slip is 'somewhat' critical ... lol. there will be some obviously, but it will be preferably minimized.
I wouldn't have thought that the fit-up would be excessively bad by using match-drilling (instead of predrilling and oversizing)
DRW
RE: Trying to simulate a clip critical connection with a bearing condition
Dik
RE: Trying to simulate a clip critical connection with a bearing condition
The new splice steel will be located up against cut steel, and splice plates will be through-matchdrilled. Nominal diameter holes will be drilled for the bolts (i.e. 1" hole for a 1" bolt), and each of the bolts will be 'encouraged' to fit.
We are an engineering and construction company, so we will have our personnel for the fit-up. The fabrication will simply be making the splice steel without pre-drilled bolt holes. The existing in-situ steel will obviously not have bolt holes, and hence we will already have to drill on site - thus it won't be a lot more work to through drill instead of pre-drilling.
DRW
RE: Trying to simulate a clip critical connection with a bearing condition
Hg
Eng-Tips policies: FAQ731-376
RE: Trying to simulate a clip critical connection with a bearing condition
RE: Trying to simulate a clip critical connection with a bearing condition
Dik
RE: Trying to simulate a clip critical connection with a bearing condition
RE: Trying to simulate a clip critical connection with a bearing condition
dik - I'm not sure how a filler type material would work, but an epoxy would be conceivable - but without any experience with this material/adhesive, the client (and myself) would be pretty shy about using it in this application as the consequences of it failing would be disastrous.
mog69 - I was thinking that the match drilling would occur one bolt at a time. as the bolt hole is drilled, the bolt would but put in place and tightened, and then move onto drilling the next hole. The notion of providing undersized holes, and consequently reaming out to match for alignment is intriguing as the reaming process would be quicker than full diameter through bolting...
I never heard of barrel bolts pre se - but i guess you are just suggesting using a machined bolt with a died (sp?) smaller thread diameter.
The use of liquid nitrogen would likely be out of the question, and even dry ice may not be too popular for this site...
Thanks for the ideas!
DRW
RE: Trying to simulate a clip critical connection with a bearing condition
RE: Trying to simulate a clip critical connection with a bearing condition
RE: Trying to simulate a clip critical connection with a bearing condition
Dik