Vibration Table Setup Sanity Check

[Transient1]

I've got a shaker table, with a plate mounted on it. This plate is the mounting plate for units under test. On this plate an accelerometer is placed. Am I correct to think that the accelerometer on the mounting plate, should reflect almost identically the input from the shaker table?

Basically, my vibe testing guy is telling me that it is natural to see system resonances in the shaker table under 2000 Hz. That seems erroneous. There should be no resonances in the frequency range of my tests. If there are , I would have to increase the number of mounting points on the test plate or increase the plates stiffness. Thanks for your input.

 

[IRstuff]

drat...

unless the cart is substantially more substantial than the pendulum.

TTFN

FAQ731-376

 

[floattuber]

Depending on the levels, a properly aligned slip plate will never touch the granite underneath so "keeping the table slipping" shouldn't be a problem.

I say depending on the levels because I've seen some extremely robust tests which have pushed out all the oil faster than the pump can replenish it.

 

[IRstuff]

The resonance wasn't from the slip plate touching the base, but from the rocking motion of the plate while riding on the oil.

TTFN

FAQ731-376