An alternative estimate for initial yield would be to use M/I=s1/y
where s1 is the yield stress times the 'fullness' of the bundle.
My /guess/ is the bundle will act as a single bar in bending, and that's the upper bound on M.
The required bending moment for fully plastic deformation will be somewhere between 15 times the moment of plasticity ((d^3/6)*yield_stress) of a single bar, and that of the entire cross section, which would be about 3 times bigger.
But the bundle will be permanently bent once the outer fibres...
Yes the first critical speed of the shaft is the first bending mode of the non rotating shaft.
Am I right in thinking that gyroscopic and centrifugal forces seem to influence the lateral natural frequencies of the shaft in the rotating reference, as they essentially provide a "stiffening"...
"May also want to rethink the pool on the roof thing in earthquake prone areas"
Could go either way. Correctly designed they could act as a Tuned Mass Damper. I haven't done the numbers.
"free-falling objects experience no acceleration due to the body force" in their own non inertial frame of reference.
Using a non inertial reference frame will tend to end in tears. Consider a 3 body universe. The earth. The hapless observer near the earth, who is the frame of reference. And a...
Net zero could make flying “something for the privileged”, the boss of Qantas has warned.
Vanessa Hudson, the chief executive of the Australian flag carrier, said the higher costs associated with clean fuel were likely to push up air fares and could put them out of reach of the masses.
Her...
"if it does spark at the top of the exhaust stroke, perhaps it doesn't matter. (I hope not.) " It doesn't, it's called wasted spark and is benign. https://en.wikipedia.org/wiki/Wasted_spark_system
I have seen successful estimates of stick slip problems, you need to know the axial and radial compliance of the blocks and of course the coefficients of friction, as well as all the other obvious properties of the system
I sort of doubt that UTS is the most important property of the pin material. I'd take a guess that most excavators use something designed to be hit with sledgehammers and covered in wet gravel. Somewhere between mild steel and axle steel.
Shrugs. Without details of the payload, geometry of the tubes etc then it's all going to be handwavium but at a guess you have a non linear kitchen drawer sticking type problem if you only have one set of acetal blocks. 92 Hz is irrelevant.
Never heard of it. Here's wiki https://en.wikipedia.org/wiki/Nuclear_Now
Nuclear is expensive. About $10B/GW. Wind and solar and batteries comes in at only $30B/GW of 24/7 power, although to be fair there is another 1.5 GW of 'free' power when the sun shines or the wind blows more than average...
Ripple looks like it had a history of financial monkey business, and also had late connections for their windfarms.
https://au.trustpilot.com/review/www.rippleenergy.com?page=3
Just to add to the complexity the plastic moment method for steel frames actually assumes yield throughout the cross sections that form the hinges. So the structure is still intact, if bent. Similarly the crumple zones on car are designed for post yield integrity.
