FEM analysis from Freecad manual using Freecad 0.18

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Gurbhej Singh
Posts: 19
Joined: Thu Sep 27, 2018 10:19 am

FEM analysis from Freecad manual using Freecad 0.18

Postby Gurbhej Singh » Wed Jan 23, 2019 6:43 pm

I tried to do the Finite Element Analysis of a simple house as explained by the FreeCAD manual. I am using 0.18 version FreeCAD, but the FEM Analysis described by the FreeCAD manual is done using FreeCAD 16. Because of which I face problems while doing the analysis.

On following the steps of manual, after producing mesh and providing material to the mesh the problem occurs. After the meshing and material step, when we select the fixed constraint command our structure gets disappeared from the screen and we have no structure to provide the constraint.
Then I close the command and try to find the issue in the Tree view, I found there that the meshing group got hidden automatically. Then I press spacebar button to make it visible. But when again I tried to provide the fixed constraint, the structure gets invisible from the screen. This means that on every time when I tried to execute any command after providing meshing and material this issue occurs.

Then I tried to do this exercise, with little changes. After selecting the analysis command instead of producing mesh as explained by the manual, I provide material. Afterwards as described by the FreeCAD manual constraint and pressure are provided. Then I produce the meshing and finally, the calculation is done. If we execute this way the analysis process gives results.

I also tried this exercise with the FreeCAD 16. When following the steps of manual after providing the material when I attempt to provide the constraints, the produced mesh hides but the structure remains there. So we can provide the constraint and afterwards we can make it visible using the spacebar. After that when we tried to provide the pressure, again the meshing hides and after providing the pressure we have to make it visible.

Below given is the link for the FreeCAD manual from which the exercise Creating FEM analysis which is on page 140 is done:

https://www.freecadweb.org/manual/a-freecad-manual.pdf

These are the conclusions I have found from whole work which I have done. Please help me to confirm that manual procedure need updation for FreeCAD 0.18 or there is any bug in this version of the software.
Thank You.
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cnirbhay
Posts: 116
Joined: Wed Aug 17, 2016 4:24 pm

Re: FEM analysis from Freecad manual using Freecad 0.18

Postby cnirbhay » Sun Jan 27, 2019 2:37 pm

You just have to simply unhide the structure again to apply material, constraints and loads. Don't worry about the mesh unhiding.
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Gurbhej Singh
Posts: 19
Joined: Thu Sep 27, 2018 10:19 am

Re: FEM analysis from Freecad manual using Freecad 0.18

Postby Gurbhej Singh » Wed Jan 30, 2019 4:08 pm

Thank you for your reply, sir I have followed the step as you suggest and able to complete the process of FEM analysis. But I have noticed some difference during result mesh presentation between the process mentioned in the manual and in the other process, I have used for the FEM analysis as explained in my previous reply. This difference is as shown in the snapshots below:

link to snapshot of process followed the steps of manual
https://drive.google.com/open?id=1KvVpF ... vXH_FGw57Z

link to snapshot of other process
https://drive.google.com/open?id=1v0N-7 ... 73u8DNdNGM

Please help me to understand this difference.
kisolre
Posts: 2258
Joined: Wed Nov 21, 2018 1:13 pm

Re: FEM analysis from Freecad manual using Freecad 0.18

Postby kisolre » Wed Jan 30, 2019 5:00 pm

Not on the question but you can append pictures to the post and put them inline your post like so:

"link to snapshot of process followed the steps of manual
Screenshot (125).png
Screenshot (125).png (210.65 KiB) Viewed 252 times
link to snapshot of other process
Screenshot (126).png
Screenshot (126).png (239.15 KiB) Viewed 252 times
"
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Gurbhej Singh
Posts: 19
Joined: Thu Sep 27, 2018 10:19 am

Re: FEM analysis from Freecad manual using Freecad 0.18

Postby Gurbhej Singh » Wed Jan 30, 2019 6:03 pm

kisolre wrote:
Wed Jan 30, 2019 5:00 pm
Not on the question but you can append pictures to the post and put them inline your post like so:

"link to snapshot of process followed the steps of manual
Screenshot (125).png
link to snapshot of other process
Screenshot (126).png
"
Thank you very much for the suggestion. I will keep this in mind for next time.