Pallet Rack Connections

[peinma]

I'm performing an analysis of an existing pallet rack system. The beam to column connection is a "teardrop" boltless connection. The connection needs to take some moment for seismic forces in the longitudianl direction (parrallel to thespan of the beams). A previous set of calculations limits the end fixity to 25% or 2000 in-lbs, but I'm not sure why. Does anyone have any information on this type of connection. The brand is Prest Lock 2, and they appear to be out-of-business. Thanks.

 

[DijonEIT]

I found this after a quick search, it looks fairly similar to the Prest Lock 2.

http://www.ridgurak.com/products/pallet-rack/teardrop-pallet-rack/

Maybe you could give them a call and see if they have any information.

 

[JoshPlumSE]

The moment connections on these sorts of rack systems do not tend to be very rigid. Therefore, if you analyze the structure with the connections modeled rigidly then you get very little drift (which is a significant design consideration for these systems). In reality, you will get much greater drift which leads to larger 2nd order moment amplification and such.

That being said, I'm not sure what is meant by "Limiting end fixity to 25% or 2000 lb-in". To me, the key is looking at the moment rotation curve established from testing. Then adjusting your analysis model to match the elastic rigidity of these curves.

 

[peinma]

Thanks for the responses. I called Ridgurak. Their engineer was helpful with background info. Unfortunately, with the manufacturer out of business, I can't get the moment rotation curves.

I modeled the upright only with pins (x direction) at the beam locations. I added moments to account for partial fixity in the beams and to account for amplification from drift. I'm making some assumptions, so I'll need to review further. Thanks again.