Crane outrigger loading type problem

[RogerRabbit99]

Hi There,

I have what I imagine is a simple engineering problem but cant seem to find a solution at present, so would be great if you could guys could shed some light.
the problem is similar to a crane with four outriggers but in this case the outriggers are fixed in all degrees of freedom (as if they are bolted in situ)

I am trying to find the distribution of load for each foot/outrigger for varying angles of slew and increase/decrease in moment assuming the platform is of uniform stiffness.
any help on this would be greatly received
Thanks in advance,
Ben

 

[JStephen]

In a case like that, you can't determine loads at the outriggers without considering stiffness and deflection of the crane itself and of the surface to which it is attached. Depending on the details, that might involve frame software or finite element analysis. You might be able to make simplifying assumptions or determine some worse-case scenarios, but that would involve looking at more detail also.

 

[Lomarandil]

If you have room in the design for an approximation, and the bolted connections don't require consideration of moment fixity, we've found that the maximum outrigger load is typically less than 50% of the total crane and pick weight (when the pick is over that outrigger, land based hydro crane w/o list, typical chart with large counterweight, etc).

It's been a while, but I also recall doing some calculations to find outrigger reactions just solving 3D FBDs and assuming rigidity everywhere.