Frequency analysis

sgrogan · September 1, 2015, 6:09pm

Hello Serchu, again.
Please see my other post. http://forum.freecadweb.org/viewtopic.php?f=4&p=98825#p98825
This frequency analysis is in developement. It is not available in the windows snapshots or the Ubuntu PPA to test you need to compile PrzemoF’s private github branch.
I can try to post some Windows builds later today if your interested. Let me know here.

Serchu · September 1, 2015, 7:23pm

Dear Sgrogan, I’m very interesting in following the new characterisitics of the FEA module, if you can compile a Windows64 version every so on I will be very happy and serve you as tester.

sgrogan · September 1, 2015, 9:21pm

I’m also a tester, not a developer. My “service” is to do some testing and offer my insights, sometimes brilliant , sometimes irrelevant.
Some Win builds for this branch can be found here:https://www.dropbox.com/sh/b2f3if41iww2xtx/AAAoAcEi3YdYmRX8jaKgwpdba?dl=0

Jee-Bee · September 2, 2015, 7:44am

Oke how do i check which frequencies the mode shapes are??
I just started with a basic 4 times clamed square plate (200x200x2 mm) and only force normal pressure
According to my calculations the first six modeshapes are arround [437.46 892.31 892.31 1316.40 1599.61 1606.91] hz
I can’t find that anywhere…
Test_fem.tar.gz (858 KB)

PrzemoF · September 2, 2015, 8:15am

Open .dat file in the calculation directory - the info you’re looking for is there. FreeCAD is not importing it yet.

Jee-Bee · September 2, 2015, 8:18am

Don’t see it
txt file is the dat file
Part__Feature_Mesh_dat.txt (168 KB)

PrzemoF · September 2, 2015, 8:23am

You didn’t run frequency analysis, just normal static analysis. Can you send your FreeCAD version info?

PrzemoF · September 2, 2015, 8:31am

The .dat file is too big to post it, but that’s what I got for your model:

     E I G E N V A L U E   O U T P U T

 MODE NO    EIGENVALUE                       FREQUENCY   
                                     REAL PART            IMAGINARY PART
                           (RAD/TIME)      (CYCLES/TIME     (RAD/TIME)

      1   0.9214515E+07   0.3035542E+04   0.4831215E+03   0.0000000E+00
      2   0.4324221E+08   0.6575881E+04   0.1046584E+04   0.0000000E+00
      3   0.4524652E+08   0.6726553E+04   0.1070564E+04   0.0000000E+00
      4   0.1116733E+09   0.1056756E+05   0.1681879E+04   0.0000000E+00
      5   0.1752228E+09   0.1323717E+05   0.2106762E+04   0.0000000E+00
      6   0.1775699E+09   0.1332554E+05   0.2120825E+04   0.0000000E+00
      7   0.2977666E+09   0.1725592E+05   0.2746364E+04   0.0000000E+00
      8   0.3142493E+09   0.1772708E+05   0.2821352E+04   0.0000000E+00
      9   0.5699248E+09   0.2387310E+05   0.3799521E+04   0.0000000E+00
     10   0.6258365E+09   0.2501673E+05   0.3981535E+04   0.0000000E+00

     P A R T I C I P A T I O N   F A C T O R S

MODE NO.   X-COMPONENT     Y-COMPONENT     Z-COMPONENT     X-ROTATION      Y-ROTATION      Z-ROTATION

      1  -0.1101798E-07  -0.1483187E-06   0.1714749E-01  -0.7070093E-01  -0.2341264E-03  -0.4660632E-06
      2  -0.1451572E-06   0.2344101E-06  -0.9910787E-04  -0.5645843E+00  -0.5053591E+00   0.1455623E-05
      3   0.2309252E-06   0.1364810E-06   0.1752227E-03   0.5145110E+00  -0.5599058E+00  -0.3254505E-05
      4   0.6308117E-06  -0.5468559E-07   0.2221658E-03  -0.3193214E-02  -0.2470342E-02   0.1543172E-04
      5   0.1177178E-06   0.4889221E-06  -0.9959675E-02   0.4128305E-01  -0.2435800E-01   0.6536849E-06
      6  -0.7556868E-07  -0.3165870E-07  -0.4837509E-03  -0.1205624E-01   0.5071206E-02  -0.1258939E-04
      7   0.5082467E-07   0.3517168E-06   0.1182215E-03   0.4717605E-01  -0.3008922E+00   0.2818943E-04
      8   0.5943400E-06  -0.5377066E-06   0.1007970E-03   0.2957567E+00   0.7785357E-01  -0.7355986E-06
      9  -0.3385725E-06   0.2533214E-06   0.8146686E-03  -0.2277752E+00  -0.3590970E+00  -0.1507993E-04
     10  -0.1200800E-06   0.1962584E-07  -0.1195887E-02  -0.3538898E+00   0.2357888E+00  -0.8678511E-05

     E F F E C T I V E   M O D A L   M A S S

MODE NO.   X-COMPONENT     Y-COMPONENT     Z-COMPONENT     X-ROTATION      Y-ROTATION      Z-ROTATION

      1   0.1213958E-15   0.2199843E-13   0.2940364E-03   0.4998621E-02   0.5481517E-07   0.2172149E-12
      2   0.2107060E-13   0.5494811E-13   0.9822370E-08   0.3187555E+00   0.2553878E+00   0.2118839E-11
      3   0.5332645E-13   0.1862707E-13   0.3070300E-07   0.2647215E+00   0.3134945E+00   0.1059181E-10
      4   0.3979234E-12   0.2990514E-14   0.4935766E-07   0.1019662E-04   0.6102592E-05   0.2381380E-09
      5   0.1385748E-13   0.2390448E-12   0.9919513E-04   0.1704290E-02   0.5933124E-03   0.4273040E-12
      6   0.5710625E-14   0.1002273E-14   0.2340149E-06   0.1453530E-03   0.2571713E-04   0.1584928E-09
      7   0.2583147E-14   0.1237047E-12   0.1397632E-07   0.2225580E-02   0.9053613E-01   0.7946440E-09
      8   0.3532401E-12   0.2891284E-12   0.1016003E-07   0.8747205E-01   0.6061178E-02   0.5411053E-12
      9   0.1146314E-12   0.6417172E-13   0.6636849E-06   0.5188155E-01   0.1289507E+00   0.2274041E-09
     10   0.1441921E-13   0.3851735E-15   0.1430145E-05   0.1252380E+00   0.5559636E-01   0.7531656E-10
TOTAL     0.9768837E-12   0.8160013E-12   0.3956734E-03   0.8571526E+00   0.8506518E+00   0.1507892E-08

     T O T A L   E F F E C T I V E   M A S S

MODE NO.   X-COMPONENT     Y-COMPONENT     Z-COMPONENT     X-ROTATION      Y-ROTATION      Z-ROTATION

          0.5835370E-03   0.5835370E-03   0.5835370E-03   0.1793014E+01   0.1783589E+01   0.3575053E+01


                    E I G E N V A L U E    N U M B E R     1


 displacements (vx,vy,vz) for set NALL and time  0.1000000E+01

         1  0.000000E+00  0.000000E+00  0.000000E+00
         2  0.000000E+00  0.000000E+00  0.000000E+00
         3  0.000000E+00  0.000000E+00  0.000000E+00
         4  0.000000E+00  0.000000E+00  0.000000E+00
         5  0.000000E+00  0.000000E+00  0.000000E+00
         6  0.000000E+00  0.000000E+00  0.000000E+00
         [..]

Jee-Bee · September 2, 2015, 8:37am

OS: Ubuntu 15.04
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.Unknown
Build type: Unknown
Python version: 2.7.9
Qt version: 4.8.6
Coin version: 4.0.0a

As far as i can see know it didn’t use my normal place… but can’t find out(yet) where he put’s the data…

PrzemoF · September 2, 2015, 8:51am

Set a directory in FEM Preferences. Did you compile FreeCAD yourself or it’s a build by sgrogan?

Right now the frequency analysis is only in my github frequency branch:

OS: Linux
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.5423 (Git)
Build type: Unknown
Branch: frequency
Hash: 4946043643372d8a00f7a1dd625171661a86ff69
Python version: 2.7.8
Qt version: 4.8.6
Coin version: 3.1.3
OCC version: 6.7.1.oce-0.16

Jee-Bee · September 2, 2015, 9:02am

Self build but i used the GIt download not from terminal i didn’t get that to work (directly)

But i found already the stuff. The calculix use the term of the last used feautere. So evertying is calling Feature_Part or box or …
So it is more difficult to find out whats new.
Verry annoiing. It the name of the FEM data could change to file name that would be great!!

bernd · September 2, 2015, 9:52am

The name of the FEMMesh ist taken for the CalculiX input file name. See https://github.com/FreeCAD/FreeCAD/blob/993a8a858380e2e17eb062a20d807c5cd4d25608/src/Mod/Fem/ccxInpWriter.py#L20

bernd · September 2, 2015, 10:03am

change the line from:

        self.base_name = self.dir_name + '/' + self.mesh_object.Name

too

        self.base_name = self.dir_name + '/' + self.mesh_object.Label

and restart your FreeCAD. The label of the FemMesh will be taken. You can easely change the label off the FemMesh and thus the file name off the CalculiX input file.

bernd · September 2, 2015, 10:16am

sorry for that many post in this regard …

take the following line and you will be fine

        self.base_name = self.dir_name + '/' + FreeCAD.ActiveDocument.Name

but be careful with spaces and special character. They could cause problems …

Serchu · September 2, 2015, 11:46am

Hi, I have problems also with the name of the generated Calculix files, maybe would be great if they can be the same as the analysis on the FreeCAD tree. We normally run several load cases for the same part, so having the Calculix files correctly named is very good for archiving.

Regards, and thanks in advance for your work in the FEM workbench.

bernd · September 2, 2015, 11:57am

could some off the moderators move that CalculiX file name stuff in a separate thread ?!?

BTW: Analysis Name up to date will allways be MechanicalAnalysis …

bernd · September 3, 2015, 5:42am

Wow, Przemo it’s so cool, it really makes fun …

Just a note. Why puting the adjustments of the analysis into global FreeCAD preferences? How about saving them as properties into the FreeCADdocument. With this we could save different adjustments for different FreeCADdocuments. How about an analysis object which holds all such properties. If the start calculation is pressed all analysis objects are calculated one by one. Batch calculation would be possible even inside the GUI.

scalling of the first modal form could be better …

Jee-Bee · September 3, 2015, 7:32am

If you mean the same as what i said on page 2(http://forum.freecadweb.org/viewtopic.php?f=18&t=12189&start=10#p98812) then i agree with you!

PrzemoF · September 3, 2015, 8:07am

Thanks for testing and the comments! What would be the best place too edit those document preferences? Looks like we might need a frequency analysis GUI window to change the parameters like max allowed deformation (hardcoded to 10% now) or the number of frequencies calculated (hardcoded to 10 now).

Jee-Bee · September 3, 2015, 8:32am

Something like this

Or otherwise a pop-up screen

With serval parameters

number of modes OR Frequency range or max (min and serval modes)
deformation
Showing frequnecy on screen
make movie (scaling between -1 and +1) if possible

some parameter changes (like material or dimensions etc )but maybe is that to complex to create for now