aisc bolted connection question

huangyhg

aisc bolted connection question.
section j3.10 bearing strength at bolt holes (13th ed.)
when is deformation at the bolt holes at service load design consideration?  what type of situation dont you consider it?
also, how did they come up with equation j3-6a b and c?
thanks!
never, but never question engineer's judgement
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there is a pretty good discussion of this on page 16.1-350 (it starts as the last sentence on 16.1-349).
ok, that explains about the factors.  when do you think i should use eq a or b?  that is what they dont explain.
never, but never question engineer's judgement
when do you think you should use them?
all i am asking is, when do you have to consider the deformation?  what type of structure?  lateral   
it all depends. lateral   
i just wanted to know your thoughts first...
you would want to consider deformation, for instance, if you are trying to allow the bolts to slip in a slotted hole.  you don't want too much bearing deformation letting the bolt "dig in" to the base material.  this would put it in a dip and keep it from slipping.  
good explaination ucfse!  right now i am desigining it with short slotted hole just for tolarance.  i think since bearing usually doesnt control in most cases, i would just use the conservative number.   
never, but never question engineer's judgement