Structural Analysis (part 1)

Consulting the book Structural Design for the Stage from Music Books Plus, I got the result that my original idea of constructing the rings from 2" black pipe or 2" square tubing would fail!

To simplify the analysis, I straightened the ring. Perhaps this was too conservative; only further analysis will tell. Anyway, it turns out that if one has a 38-foot long flat structure that is supported only by the ends, it needs to be pretty stiff. In fact, according to the analysis, 5" pipe is needed! This change makes the structure gain weight from 500 lbs to 1300 lbs. And all of this steel holds up only 61 lbs of plywood panels.

I'm hoping that a less pessimistic analysis will show that I can use a less expensive approach. Perhaps I should consider using cables to stiffen the rings. Maybe I can use the tubing and fittings of chain-link fencing?

Larger Ring

The analysis above includes a change to the overall design. I've not liked the interference between the sofa and the projection surface. And I've been concerned with the apparent size of the ring, as seen on the playa. So, the latest design eliminates the sofa but increases the size of the ring from 16 feet in diameter to 24 feet.

That increase means that a stronger frame is needed.