Determining dynamic compliance - complicated matter?

Posted by Thomas_A (A) on January 30, 2010 at 02:02:19

Some discussion going on at VE regarding compliance and resonance,

static compliance is really nothing difficult - it is the "real" compliance figure at 0 Hz.

But dynamic compliance depends on damping with is affected by velocity, thus both frequency and amplitude ???

So any measurement of resonance with a sweep e.g. 20->5 Hz, will be dependent on the level of the sweep.

I've been puzzled about my measurements using the HFN vs, Ultimate Analogue Test LP (vertical resonance). It is around 8.5 Hz using HFN and 20-25 Hz using the UAT LP. THis indicates a cu of 21 and 4, respectively, depending on the test made. Very confusing, but result are quite clear.

The sweep of the UATL is at -20 dB. Does anyone know what level the low frequency sweep of the HFN LP is recorded at? Secondly, does anyone know what frequency and level 10 and 100 Hz compliance is tested? For 100 Hz I've read that it may be 50 micron amplitude, but for 10 Hz?

T

T

This post is made possible by the generous support of people like you and our sponsors:

Topic - Determining dynamic compliance - complicated matter? - Thomas_A 02:02:19 01/30/10 (14)

Not really - Mark Kelly 03:05:12 01/30/10 (13)

Agreed... - Thomas_A 03:35:14 01/30/10 (12)

Where I think the confusion lies - Mark Kelly 16:25:11 01/30/10 (1)

Ok - Thomas_A 09:52:50 01/31/10 (0)

RE: Agreed... - John Elison 06:37:59 01/30/10 (9)

What I did - Thomas_A 07:08:18 01/30/10 (8)

The sweeps should be found here - Thomas_A 07:39:58 01/30/10 (7)

RE: The sweeps should be found here - John Elison 09:27:16 01/30/10 (6)

Regarding the resonance of HFN - Thomas_A 13:33:26 01/30/10 (0)

As you say - Thomas_A 12:46:22 01/30/10 (0)

RE: The sweeps should be found here - Lew 11:48:07 01/30/10 (3)

RE: The sweeps should be found here - John Elison 12:25:14 01/30/10 (2)

Thank you, John.. - Lew 09:27:11 01/31/10 (1)

RE: Thank you, John.. - John Elison 09:45:49 01/31/10 (0)

Determining dynamic compliance - complicated matter?

Post a Message!