Cleats with slotted Holes

[civeng80]

I’ve been thinking about this for quite a while.

In connections with slotted holes in cleats and snug tight bolts, how successfully does the joint slip to accommodate steel expansion and deflections and any unwanted moments ?

 

[Ron]

Not so great. Less so with time.

 

[hokie66]

Depends a lot on the loading normal to the slots. If this slotted connection is at, say, the top of a wind column, it should work well. If on a floor beam, it won't work at all, but rather will result in binding, noise, and possibly overstress. If in a roof purlin, will probably be fine...unless there is a lot of vertical loading from snow or something.

 

[civeng80]

Is there some way to make them work better e.g. a lubricant between the steel or a special bolt that doesn't require snug tightening?

 

[CELinOttawa]

The main problem isn't the bolt or the slot, but dirt that gets into the slot and works its way in between metal plate components... This is why slot connection have been all but entirely abandoned in bridge design. I've successfully adapted bridge bearing type details to building works, but who knows how many years such details will be trouble free. I'm confident they are better than slotted connections, but have no literature or other to demonstrate so.

 

[hokie66]

Check out this failure which occurred at the Pittsburgh convention center.

http://failures.wikispaces.com/David+L.+Lawrence+Convention+Center