mzso wrote: ↑06 Mar 2026, 02:42
Tommy Cookers wrote: ↑05 Mar 2026, 21:14
resonance is only a vibration response bigger than the forced vibration response
ie resonance can occur without even a complete forcing cycle
(consider a spring balance or NASA's Challenger nonsense and Airbus Queens NY crash lies) ....
Why add wacky conspiracy theories? The airbus lost its rudder because the pilot kept stomping the pedals and over-stressed it. The challenger got destroyed because of flawed sealings that got rigid in the cold.
there's no conspiracy theories in my posts
Airbus lost its rudder because it could be overloaded (though their USP was that it couldn't be overloaded)
ie time-varying load(s) not exceeding eg 1 ton could produce a deflection corresponding to a steady load of over 1 ton
ie Airbus designers made the 'spring balance' mistake (as if 1 kg weight can only cause a reading of 1 kg)
the Space Shuttle booster pack was designed to deflect eg 1' at full thrust - and the gantry positioned to clear that
but ramping the thrust to full produced eg a deflection of 2' - and so the booster fouled the gantry on many launches
in (disaster) investigation proceedings NASA implied this was a new thing - and named it structural 'dynamic overshoot'
actually it was the 'spring balance' mistake (forgetting that 1kg weight can cause a temporary reading up to 2 kg)
yes I only found one analysis of the spring balance (years before either case)
yes it seems to be absent from the textbooks in modern times
force and deflection (though related) are not equivalent
(valve springs 'surge' is another example)