04-05-2017, 11:24 AM
(This post was last modified: 04-05-2017, 11:25 AM by Permeable Ceiling.
Edit Reason: thanks added
)
Thanks for the quick reply!
Let’s assume a meter of spoke masses 100 tons with elevators, shielding, everything really. Going in from outside, the lest stressed parts, at 3rpm and 100 radius the final meter is pulling with a force of 1,000,000 N at its more axis parts. The 2nd meter inward pulls with a little less force, since it’s closer, the radius is smaller, you know the drill; but still has the same mass, i.e. it exerts 990,000 N. But the 1st meter of the spoke is attached, so its connection to the third meter is actually stressed with 1,990,000 N. Still easy peasy for the connections to deal with, but a few iterations down the line, at 50m inside, the force is 36 MN. At 90 meter, ten from the middle of the torus and as good a point as any to connect to a hub, the spoke is pulling with a force of 50 MN.
You’re right, steel can pull that off, but up to what length, or rather to what force?
(04-05-2017, 07:35 AM)JoeStrout Wrote: As for the tapered spokes:Let me expand on that then.Quote:(1) Due to stress of centrifugal force on spoke. Spokes have mass. The longer the spoke, the more mass is pulling the closer to the hub. To have equal stress per cross sectional area, you have to widen the spokes as you get closer to the hub.
That's an interesting thought, but I'm not sure I'm buying it. The spokes are tension structures; cables would do the job just as well, except that we want them pressurized, radiation-shielded, and supporting things like elevators inside. And none of those things vary with distance from the hub.
But I'm going to think about it some more!
Let’s assume a meter of spoke masses 100 tons with elevators, shielding, everything really. Going in from outside, the lest stressed parts, at 3rpm and 100 radius the final meter is pulling with a force of 1,000,000 N at its more axis parts. The 2nd meter inward pulls with a little less force, since it’s closer, the radius is smaller, you know the drill; but still has the same mass, i.e. it exerts 990,000 N. But the 1st meter of the spoke is attached, so its connection to the third meter is actually stressed with 1,990,000 N. Still easy peasy for the connections to deal with, but a few iterations down the line, at 50m inside, the force is 36 MN. At 90 meter, ten from the middle of the torus and as good a point as any to connect to a hub, the spoke is pulling with a force of 50 MN.
You’re right, steel can pull that off, but up to what length, or rather to what force?