Requesting examples of Modal Shape

[Peter W Brown]

I'm currently using a program called LMS with a HP VXI mainframe DAQ to capture dynamic data of a scaled timber bridge. The main area of interest is the FFT, FRF and mode shapes of the structure. LMS does this well but there is a problem getting the data out in a form which is usable, nor can we get time data. We are using a VI that we made that will do the FFT, FRF, time data and able to save them in a spreadsheet file. Problem is that we have to use both programs as I'm not aware of how to use labviews data to do modal analysis eg. what 3rd party program, if there is a vi that will do this, whether we can save in sdf format so we can import into LMS. Any help would be gratefully appreciated.

[JenK]

Hi Peter,

There is an add-on toolset in LabVIEW that will allow you to do modal-analysis. You can read the description of this Advanced Signal Processing Toolset here. Please repost if you have further questions.

JenK

[Peter W Brown]

Thanks for reply. Is it possible to do the mode shapes with this add on. From reading the description it does give the modal analysis. Would it be possible to use this data to find the mode shapes in another program? I'm fairly new to mode shapes so excuse my lack of knowledge

[Philip_Courtois]

Hey Peter,

I haven't tried it, but it should be quite easy to create a 3D Graph of the measured modal data, and therby show the modal shape of your object.

Can anyone help with some examples of this?

You should try the evaluation version of the Signal Processing Toolkit from here:

Signal Processing Suite Evaluation Software