The shaking table, or base plate, is not a "non-moving mass", but is the coupling factor which transfers the energy from the sum of all the other moving masses from the strongest to the weaker. Another example of "majority rule", if you will.
Remove the resonance frequency of this coupling factor far enough from the frequency of the driving sources, e.g. by adding mass, will reduce the coupling and will reduce lock-up, although not totally eliminate it. Think of this as adding a low-pass filter between the driving and driven units. Acoustics Engineers and Loudspeaker Designers are familiar with this, as sound sources are frequently located close together and may interfere with each other. Add enough mass to the coupling factor ( walls, floors, ceiling, or speaker cabinet) to lower the resonant frequency (or frequencies) is a known cure. -- Flemming Larsen On Sep 13, 2013, at 20:47, Bob Stewart <b...@evoria.net> wrote: > And, in fact, the mass of the "shake table" has a big impact on the lock > time, as does the mass of everything else besides the mass of the pendulum > weights. Would there be a natural resonant frequency of the non-moving > masses (shake table etc) that could prevent lockup? > > > Bob _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
