Layman's explanation of random-on-random vibration
Layman's explanation of random-on-random vibration
(OP)
Anyone out there have a writeup that explains random-on-random vibration in terms a non-vibration-expert can understand?
Tunalover





RE: Layman's explanation of random-on-random vibration
Sine on Random Vibration
Sine-on-random tests combine multiple sinusoids with broadband random noise. The sine tones may be stationary or sweeping, harmonically or non-harmonically related, and have varying levels across a frequency band. Sine-on-random is an excellent tool for simulating a moving vehicle subjected to random vibration due to road variations while the engine speed is increasing or decreasing.
Random on Random Vibration
Random on random testing involves creating fixed or sweeping narrow bands of random vibration superimposed over a broadband random vibration base. Random on random vibration profiles most typically apply to testing components and systems of tracked vehicles, where the narrowband random vibration simulates track laying components and the broadband random base the rest of the vehicle.
RE: Layman's explanation of random-on-random vibration
RE: Layman's explanation of random-on-random vibration
What does SFTI stand for?
Tunalover
RE: Layman's explanation of random-on-random vibration
- Steve
RE: Layman's explanation of random-on-random vibration
Tunalover
RE: Layman's explanation of random-on-random vibration
I'm really really dubious about the truth of " the narrowband random vibration simulates track laying components", but don't have any evidence. The reason I say that is that a periodic impact has a spectral structure that has sharp spikes at the fundamental, and then 3rd 5th and so on harmonics. However, I can't readily find a vibration spectrum from a tracked vehicle.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Layman's explanation of random-on-random vibration
RE: Layman's explanation of random-on-random vibration
Imagine a pair of white noise sources.
filter one via a bandpass filter, that sweeps through the frequency range. Amplify it a bit. Add the output of that to the other source's unfiltered output.
So the spectrum would look like
CODE
xxx xxxxxxxxx
0--------------
and then a bit later
xx
xxxxx xxxxxxx
0--------------
in reality of course the broadband signal will have an upper frequency limit.
Incidentally if you are programming this yourself do NOT use a string of random numbers to generate the random noise. You will destroy your driver system.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Layman's explanation of random-on-random vibration
Tunalover
RE: Layman's explanation of random-on-random vibration
Random Vibration: Earthquake
Random-on-Random Vibration: Car suspension (or some other indirectly connected chassis) on top of shaking ground while driving on a dirt road.
The Earthquake is completely random, while the car suspension has a defined range of motion; however, it vibration (oscillation up and down) is random due to its interaction with the uneven road and its interaction with the unpredictable earthquake.
Random-on-Random...
Kyle Chandler
www.chiefengineering.net
RE: Layman's explanation of random-on-random vibration
RE: Layman's explanation of random-on-random vibration
kchan711 seems to have a pretty good description.
Tunalover
RE: Layman's explanation of random-on-random vibration
What is the STFI method? Speak plain man!
Tunalover
RE: Layman's explanation of random-on-random vibration