[SOLVED] Frequency Analysis - FEM: No nodes found in Frd file

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EkaitzEsteban
Posts: 108
Joined: Wed Sep 12, 2018 1:31 pm

[SOLVED] Frequency Analysis - FEM: No nodes found in Frd file

Post by EkaitzEsteban »

Hello,

When I perform a frequency analysis, I edit the .inp file manually including in the frecuency step:

Code: Select all

***********************************************************
** At least one step is needed to run an CalculiX analysis of FreeCAD
** written by write_step_begin function
*STEP
*FREQUENCY, SOLVER=MATRIXSTORAGE
1,0.0,100000.0
I include SOLVER=MATRIXSTORAGE option for obtaining the mass and stiffness matrices (.mas) and (.sti) files as described in the calculix manual

http://web.mit.edu/calculix_v2.7/Calcul ... de206.html

However, when I run the analysis I get the following error in the report view.

FEM: No nodes found in Frd file.
Problem on frd file import. No nodes found in frd file.
FEM: No result object in active Analysis.

The files containing stiffness and mass matrices are correctly written but there is no simulation results.

I dont know, Am I doing something wrong?

Thank you!

EDIT: fandaL solution works! https://forum.freecadweb.org/viewtopic. ... 76#p257758

However there is a small bug. Frd and the rest of the files contains all the information but (N-1) modal frequencies are displayed in the FreeCAD GUI. Shall someone check this?

best regards,

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13528 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: 5c3f7bf8ec51e2c7187789f7edba71a7aa82a88b
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: Spanish/Spain (es_ES)
Last edited by EkaitzEsteban on Tue Sep 25, 2018 9:57 am, edited 1 time in total.
Jee-Bee
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Posts: 2566
Joined: Tue Jun 16, 2015 10:32 am
Location: Netherlands

Re: [Problem] Frequency Analysis - FEM: No nodes found in Frd file

Post by Jee-Bee »

I guess looking to the link it should be

Code: Select all

***********************************************************
** At least one step is needed to run an CalculiX analysis of FreeCAD
** written by write_step_begin function
*STEP
*FREQUENCY, MATRIXSTORAGE
1,0.0,100000.0
otherwise does it werks with default analysis??
fandaL
Posts: 440
Joined: Thu Jul 24, 2014 8:29 am

Re: [Problem] Frequency Analysis - FEM: No nodes found in Frd file

Post by fandaL »

... Notice that the program stops after creating these files. No further steps
are treated. Consequently, *FREQUENCY, MATRIXSTORAGE only makes
sense as the last step in a calculation.
It seems that saving stiffness and mass matrices is taken as a separate step (last one) which does not calculate the analysis itself.

Try to add it as the last step. Previous step could be the frequency calculation as usual, e.g.:

Code: Select all

*STEP
*FREQUENCY
5

** Fixed Constraints
*BOUNDARY
FemConstraintFixed,1
FemConstraintFixed,2
FemConstraintFixed,3

** Outputs --> frd file
*NODE FILE
U

*END STEP


** added step for saving mass and stiffness matrices
*STEP
*FREQUENCY, SOLVER=MATRIXSTORAGE

*END STEP
EkaitzEsteban
Posts: 108
Joined: Wed Sep 12, 2018 1:31 pm

Re: [Problem] Frequency Analysis - FEM: No nodes found in Frd file

Post by EkaitzEsteban »

Jee-Bee wrote: Fri Sep 21, 2018 5:14 pm I guess looking to the link it should be

Code: Select all

***********************************************************
** At least one step is needed to run an CalculiX analysis of FreeCAD
** written by write_step_begin function
*STEP
*FREQUENCY, MATRIXSTORAGE
1,0.0,100000.0
otherwise does it werks with default analysis??
It simulates correctly with default analysis.
EkaitzEsteban
Posts: 108
Joined: Wed Sep 12, 2018 1:31 pm

Re: [Problem] Frequency Analysis - FEM: No nodes found in Frd file

Post by EkaitzEsteban »

fandaL wrote: Fri Sep 21, 2018 8:01 pm
... Notice that the program stops after creating these files. No further steps
are treated. Consequently, *FREQUENCY, MATRIXSTORAGE only makes
sense as the last step in a calculation.
It seems that saving stiffness and mass matrices is taken as a separate step (last one) which does not calculate the analysis itself.

Try to add it as the last step. Previous step could be the frequency calculation as usual, e.g.:

Code: Select all

*STEP
*FREQUENCY
5

** Fixed Constraints
*BOUNDARY
FemConstraintFixed,1
FemConstraintFixed,2
FemConstraintFixed,3

** Outputs --> frd file
*NODE FILE
U

*END STEP


** added step for saving mass and stiffness matrices
*STEP
*FREQUENCY, SOLVER=MATRIXSTORAGE

*END STEP
Thank you fandaL, it works perfectly. Awesome!
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seppelw
Posts: 115
Joined: Tue Jan 16, 2018 11:12 pm
Location: CH/DE

Re: [SOLVED] Frequency Analysis - FEM: No nodes found in Frd file

Post by seppelw »

Hello,

sorry, but I fo not understand what needs to be changed, I have the same error.

What does need to be deletedd and added at the end of the file?

Thanks a lot, Seppel
Attachments
FEMMeshGmsh.inp.txt
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lponz
Posts: 2
Joined: Wed Dec 29, 2021 12:15 pm

Re: [SOLVED] Frequency Analysis - FEM: No nodes found in Frd file

Post by lponz »

Hi all,

I made several trials as suggested but am still unsuccessful with release 0.19.3.
That's the reason why I downloaded the previous previous version here below for a last attempt.
Could you @EkaitzEsteban send an example (inp and fcstd files) running well your side ?

Thanks

OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24291 (Git)
Build type: Release
Branch: releases/FreeCAD-0-19
Hash: 7b5e18a0759de778b74d3a5c17eba9cb815035ac
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.0
Locale: French/France (fr_FR)
lponz
Posts: 2
Joined: Wed Dec 29, 2021 12:15 pm

Re: [SOLVED] Frequency Analysis - FEM: No nodes found in Frd file

Post by lponz »

Ok,

I finally installed release 0.18.4 here below and it works fine as is, with no modification of the inp file !

Dear Freecad developpers, could you check what's wrong with last release 0.19.3 and Calculix frequency analysis (eigenmodes) ?
("No nodes found in frd file")

Thanks for this marvellous open source tool anyway and wish you the best for the coming new year :)

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4 (GitTag)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 980bf9060e28555fecd9e3462f68ca74007b70f8
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)
thschrader
Veteran
Posts: 3132
Joined: Sat May 20, 2017 12:06 pm
Location: Germany

Re: [SOLVED] Frequency Analysis - FEM: No nodes found in Frd file

Post by thschrader »

lponz wrote: Thu Dec 30, 2021 6:19 pm Dear Freecad developpers, could you check what's wrong with last release 0.19.3 and Calculix frequency analysis (eigenmodes) ?
("No nodes found in frd file")
Related problem, but solved:
https://forum.freecadweb.org/viewtopic.php?f=13&t=64834
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