Resonance dwell nomenclature
Resonance dwell nomenclature
(OP)
What do the terms "resonance dwell" mean to you? Does it mean tracking dwell or fixed freqency dwell?
Or is it more of a general term that further needs to be defined by "track" or "fixed"?
Or is it more of a general term that further needs to be defined by "track" or "fixed"?





RE: Resonance dwell nomenclature
We did this a lot during gas turbine testing to gauge the life of the engine structure as the turbine sped up to operating speed passing through each components resonance.
Jim
Jim Kinney
Kennedy Space Center, FL
RE: Resonance dwell nomenclature
Tobalcane
"If you avoid failure, you also avoid success."
"Luck is where preparation meets opportunity"
RE: Resonance dwell nomenclature
At this site, the conventional nomenclature of "Resonance Dwell" specifically means a tracked dwell (follow any frequency shifts) while "Fixed frequency" means stay with one frequency regardless of whether there is a shift in the resonant frequency.
To me, "resonance dwell" needs the qualifer "tracked" or "fixed" to mean anything. I wanted to know if there is a standard industry definition.
RE: Resonance dwell nomenclature
The resonance frequency has to be interpreted from a g/rms chart or displacement chart. It will vary depending on the part and where you are sensing during testing.
A parts resonant frequency cooresponds with its natural frequency. Generally each harmonic is a multiple of its natural frequency. Testing a "resonance dwell" is generally much more intense of a test being that you can see spikes of 10 to 20 times more g's at the natural freqency.
StrykerTECH Engineering Staff
Milwaukee, WI
http://www.stryker-tech.com/
RE: Resonance dwell nomenclature
They will show up as spikes on your grms read out.
StrykerTECH Engineering Staff
Milwaukee, WI
http://www.stryker-tech.com/
RE: Resonance dwell nomenclature
Here we have two routes, we can stay at one frequency regardless of any shift or the computer can continuously track and adjust the frequency to maximize the response.
RE: Resonance dwell nomenclature
But, . . . why is it shifting? Generally that means one of two things. poor fixturing or the structure/part/assembly is yielding and through the course of the yeilding its natural frequency is changing, which is generally bad.
StrykerTECH Engineering Staff
Milwaukee, WI
http://www.stryker-tech.com/
RE: Resonance dwell nomenclature
Tobalcane
"If you avoid failure, you also avoid success."
"Luck is where preparation meets opportunity"
RE: Resonance dwell nomenclature
First do a sine sweep to find the natural frequency of your part. Next determine the frequency where the amplitude is maximun and store the value of the phase.
Then do vibration endurance with the phase constant.