Random on random

[izax1]

I have a vibration spec where a "floor level" broadband random data is given. Additionally 5 narrowbands are given with frequency data and PSD. For each narrowband a Sweep Bandwith (SB) is defined. For example for narrowband 1 a PSD level is given for 20, 40, 60, 80 and 100 Hz with SB 5. I assume each of the frequencies given is then the center frequency for each band. So with SB 5 the first RoR bandwith would be from 17.5 to 22.5 Hz, the second from 37.5 to 42.5 Hz. and so on. Is this correctly understood?

Thanks for any help

 

[GregLocock]

That looks like some milspec for engine type vibration. I don't know if your interpretation is correct.

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Ron]

Agree with Greg....what are you measuring vibrations on?

 

[floattuber]

That's something where you need to have your customer clarify what they mean. It's ambiguous and can be interpreted different ways.