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Get list of natural frequencies from a modal analysis

Is there a way to get a list of the natural frequencies solved for in a modal analysis, other than manually noting them one-by-one?

5 REPLIES
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Accepted by topic author Kava
‎05-25-2016 06:25 AM

Re: Get list of natural frequencies from a modal analysis

Dear Kava,

Check the nastran output file *.F06, there you have the eigenvalue results computed by NX Nastran solver, for instance:

 

 

                          E I G E N V A L U E  A N A L Y S I S   S U M M A R Y   (READ MODULE)
                                     BLOCK SIZE USED ......................    7
                                     NUMBER OF DECOMPOSITIONS .............    2
                                     NUMBER OF ROOTS FOUND ................   10
                                     NUMBER OF SOLVES REQUIRED ............   12
               
                                              R E A L   E I G E N V A L U E S
   MODE    EXTRACTION      EIGENVALUE            RADIANS             CYCLES            GENERALIZED         GENERALIZED
    NO.       ORDER                                                                       MASS              STIFFNESS
        1         1        2.705817E+05        5.201746E+02        8.278836E+01        1.000000E+00        2.705817E+05
        2         2        2.705900E+05        5.201827E+02        8.278964E+01        1.000000E+00        2.705900E+05
        3         3        1.462022E+06        1.209141E+03        1.924408E+02        1.000000E+00        1.462022E+06
        4         4        3.254206E+06        1.803942E+03        2.871062E+02        1.000000E+00        3.254206E+06
        5         5        3.254207E+06        1.803942E+03        2.871063E+02        1.000000E+00        3.254207E+06
        6         6        3.290790E+06        1.814053E+03        2.887155E+02        1.000000E+00        3.290790E+06
        7         7        3.290792E+06        1.814054E+03        2.887157E+02        1.000000E+00        3.290792E+06
        8         8        3.496462E+06        1.869883E+03        2.976011E+02        1.000000E+00        3.496462E+06
        9         9        3.892409E+06        1.972919E+03        3.139998E+02        1.000000E+00        3.892409E+06
       10        10        3.892412E+06        1.972920E+03        3.139999E+02        1.000000E+00        3.892412E+06

Best regards,

Blas.

 

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Get list of natural frequencies from a modal analysis

Hi Kava,

 

In the Simulation Navigator(not in Post Processing Navigator) right click the solution you are interested and in the context menu click "Setup Report". It may take some time of NX to create the report. After the report is created you can double click it and all the information about the solution - including results(in your case frequencies) - will open in your default browser.

 

Best regards,

 

Candas

 

Candas Urunga, Founder/Engineer

www.ecan.com.tr

Re: Get list of natural frequencies from a modal analysis

Thanks Candas, but this was a FEMAP question. The forum merger has made it slightly less clear where posts are I guess.

Re: Get list of natural frequencies from a modal analysis

Sorry thats my mistake...If you like, you can delete it.

 

Best regards,

 

Candas

 

Candas Urunga, Founder/Engineer

www.ecan.com.tr

Re: Get list of natural frequencies from a modal analysis

I have attached an API that will allow you to pick a Study and list the titles of all of the sets in the study. For a Modal analysis that should give you something like this...

 

Study 1..NX Nastran Modes Analysis Set
2..Mode 1, 56.35941 Hz
3..Mode 2, 61.41957 Hz
4..Mode 3, 78.30073 Hz
5..Mode 4, 79.32263 Hz
6..Mode 5, 82.12699 Hz

 

Not sure if that is what you wanted, but the API shouldn't be too hard to tweak to get something similar.