stabilization diagram and frequency range

Hello,

During our last modal test with Version 2022.1, we encountered the following phenomenon:

We get different results in the stabilization diagram depending on the settings for the highest frequency (see below).

Is there an explanation for this behavior? Is this “normal”?

Dear Mr. Rieger,

the LSCF algorithm fits the curve with the polynomial order defined in the settings (in your case, this was the polynomial up to the 24th order).

The main purpose of curve fitting is to mathematically represent the modal data in the best way possible.

The algorithm does the curve fitting in the defined frequency range. So it really depends on your data if some peaks may be missed if the whole range is selected.

The order needs to be set high enough to be able to fit the function to all modes included in the selected frequency range/band.

Best regards,