Begging for help regarding temperature FEM analysis

About the development of the FEM module/workbench.

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lighting_freak
Posts: 9
Joined: Wed Mar 04, 2020 9:05 am

Begging for help regarding temperature FEM analysis

Postby lighting_freak » Wed Mar 04, 2020 9:24 am

Hello all,

I'm new to FreeCAD and I'm also new in the topic of FEM analysis. In my everyday life I'm an optical engineer that takes care about illumination optics. From personal interest I've started to learn a little about temperature analysis. Therefore I watched an several tutorial videos and I think I'm fine with the general workflow. Now the more complicated topic starts... how do I set it up to receive correct results.

My first task is an LED soldered on an PCB. How hot does the PCB become?
In attachment you'll find the "testsetup". I wonder how to define the surface touching each other in a way that the temperature calculation is right.
LED.FCStd
(50.04 KiB) Downloaded 20 times
I'm grateful for all help that I could get.
Thanks a lot.

EDIT:

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: German/Germany (de_DE)

Best regards
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Kunda1
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Re: Begging for help regarding temperature FEM analysis

Postby Kunda1 » Wed Mar 04, 2020 4:31 pm

Moved to FEM subforum (but left a shortcut in the Python Scripting subforum as well)
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Kunda1
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Re: Begging for help regarding temperature FEM analysis

Postby Kunda1 » Thu Mar 05, 2020 9:13 pm

Bumping so FEM folks can respond
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lighting_freak
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Joined: Wed Mar 04, 2020 9:05 am

Re: Begging for help regarding temperature FEM analysis

Postby lighting_freak » Fri Mar 06, 2020 9:18 am

Hi all,

is there any additional information that I should post?
This is the datasheet of the LED (direct file attachment doesn't work due to it's size):

https://dammedia.osram.info/media/resou ... .CM_EN.pdf

Please feel free to guide me through the process and ask all necessary questions.
If you recommend to switch to another FreeCAD version, please let me know. As I'm a beginner I'm totally free in that topic.
Thank you.

Best regards
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bernd
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Re: Begging for help regarding temperature FEM analysis

Postby bernd » Fri Mar 06, 2020 10:01 am

- read this topic https://forum.freecadweb.org/viewtopic.php?f=18&t=32583

- use FreeCAD 0.19 dev version

- do not delete the mesh object if you post a file, just clear the mesh object. With this the meshing properties will be kept.

bernd
lighting_freak
Posts: 9
Joined: Wed Mar 04, 2020 9:05 am

Re: Begging for help regarding temperature FEM analysis

Postby lighting_freak » Fri Mar 06, 2020 6:31 pm

Hello bernd,

thank you for reply and your hint with the related thread.
I tried to follow to basic setup, but with dev-version some errors occur:

This is the version:
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.19858 (Git)
Build type: Release
Branch: master
Hash: dbe292496b56147c081761084774f42bda56ea90
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: German/Germany (de_DE)

This is the error message appearing on clicking on the material button:

Code: Select all

name 'FemGui' is not definedRunning the Python command 'FEM_MaterialSolid' failed:
Traceback (most recent call last):
  File "C:\Users\jantschek\Downloads\FreeCAD_0.19.19858_x64_LP_12.1.2_PY3QT5-WinVS2015\Mod\Fem\femcommands\manager.py", line 138, in Activated
    self.add_obj_on_gui_set_edit(self.__class__.__name__.lstrip("_"))
  File "C:\Users\jantschek\Downloads\FreeCAD_0.19.19858_x64_LP_12.1.2_PY3QT5-WinVS2015\Mod\Fem\femcommands\manager.py", line 306, in add_obj_on_gui_set_edit
    .format(objtype)
  File "<string>", line 1, in <module>

name 'FemGui' is not defined
This is the error while trying to generate the mesh with GMSH:

Code: Select all

name 'FemGui' is not definedActive analysis found: Analysis
Traceback (most recent call last):
  File "C:\Users\jantschek\Downloads\FreeCAD_0.19.19858_x64_LP_12.1.2_PY3QT5-WinVS2015\Mod\Fem\femguiobjects\_ViewProviderFemMeshGmsh.py", line 299, in clicked
    self.run_gmsh()
  File "C:\Users\jantschek\Downloads\FreeCAD_0.19.19858_x64_LP_12.1.2_PY3QT5-WinVS2015\Mod\Fem\femguiobjects\_ViewProviderFemMeshGmsh.py", line 349, in run_gmsh
    part = self.obj.Part
<class 'AttributeError'>: '_TaskPanel' object has no attribute 'obj'
Didn't know about the clear mesh option, I'll gonna use it with the next file that I'd like to share. Thanks for that hint.

Best regards
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Kunda1
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Re: Begging for help regarding temperature FEM analysis

Postby Kunda1 » Fri Mar 06, 2020 6:45 pm

Did a search on

Code: Select all

name 'FemGui' is not defined
and came up with this, but this is not a solution: https://forum.freecadweb.org/viewtopic. ... =4&t=17169

Maybe try

Code: Select all

import FemGui
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bernd
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Re: Begging for help regarding temperature FEM analysis

Postby bernd » Sat Mar 07, 2020 8:43 am

A regression I added :oops: Lately I did some bigger code refactur ... I will fix it if I am on my computer.
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bernd
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Re: Begging for help regarding temperature FEM analysis

Postby bernd » Sat Mar 07, 2020 3:59 pm

fixed ... you need to use a FreeCAD 0.19.19946 or highter
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Kunda1
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Re: Begging for help regarding temperature FEM analysis

Postby Kunda1 » Sat Mar 07, 2020 4:26 pm

Thanks @bernd :)
lighting_freak wrote:
Fri Mar 06, 2020 6:31 pm
Please test and report back. If successful, please mark this thread [Solved] by editing the first post title. Thanks!
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