Originally Posted by
rydaddy
Again, you are completely wrong. It's obvious you have zero understanding of the concept of prestressed structures. I happen to design them for a living. Just take a wheel (with tire and air) set if on the ground vertically, and put all the weight you can at the 12:00 position. How are the forces being distributed? Does the wheel suddenly collapse? Draw that FBD and explain to me the load path.
I hope you actually read my post instead of just "blahblahblah". I took some time writing it and it's correct.
The wheel doesn't collapse for the same reason corrugated piping doesn't collapse when buried underground. Forces push the sides of the cylinder (or circle) in, preventing ovalization in the horizontal axis. You can replicate this experiment by popping the lid and bottom off of a tin can. Place the now extremely flexible cylinder between two blocks of wood, as shown in the diagram below. You can now stand on top of this assembly without crushing the can. The vertical load is transfered compressively through the rim, all the way around the perimeter, to the bottom. The tin can scenario is an especially good example of this, as there is nothing inside the can at all, and the upper and lower halves of wood are not touching.
Yes, we have actually done this experiment at the office. That's how bored we get at lunch.
Anyway, "zero understanding" is a pretty insulting judgment on my professional ability. I design buildings for a living. I'd be seriously concerned if the structural engineer on my team (or I, myself) couldn't draw a free body diagram of a spoked wheel being loaded at 12 o'clock and supported at 6 o'clock. We're liable when things go wrong, so we know what we're talking about and don't bluff about things we don't understand.