Designing a Racking System for Sheet Metal Coils

[munza]

Hi,

***I just noticed this that I posted this in the wrong section thinking I was in the engineering forum...sorry!***

I'm designing a racking system to store sheet metal coils (see attached sketch). I calculated the I and S values required and according to my calculations, 4 x 4 x 3/8 square tubing would
be strong enough. However, I'm not sure about buckling. Could somebody please tell me which equation to use (euler, jb johnson)?

Max coil weight: 8,500 lbs

Is this rack strong enough for the worst case scenario where all coils are 8,500 lbs?

Thanks for your help!

 

[anorlunda]

ping @jrmichler

 

[jrmichler]

The buckling equations for a column with simple or fixed end conditions are fairly simple, however this rack system is anything but simple. The failure mode that needs to be calculated is one where all of the columns buckle simultaneously. The entire assembly could flop over, or the columns could buckle in the middle. The rack shelves provide some restraint, but the connections are not rigid. I am not aware of any hand calculation method that can give a good answer to this problem.

Companies that make rack systems are set up to do the calculations, and this is a good reason to buy a commercial rack system. Note also that US and European machinery codes require that the allowable loads be permanently posted on the rack system.