Request for help meshing and and analysing a part {Solved}

About the development of the FEM module/workbench.

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Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

@cad1234 - you have just given me more delving to do ;)
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

thschrader wrote: Thu Sep 09, 2021 7:24 am This gives a better resolution of the buckling mode. Like in FC.
The buckling factor is mesh dependent.
Buckling-factor now 4,25. Much better.
This is very good isn’t it Thomas!
cad1234
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Re: Request for help meshing and and analysing a part

Post by cad1234 »

@thomas
even if MASTAN2 is very slow with buckle, I`m very happy that I followed your recommendation to test it and now have it, together with FC-FEM, in my tool box!
Almost all FEMs I do with FC-FEM, but in some cases, MASTAN2 can deliver additional helpful information.. I think..

@Laurie
here is a annother MASTAN2 screenshot of the normal forces, you maybe might like ;) :
red: compressive force
blue: tensile force
Set "Fill" Option for colored force display.
Attachments
Normal Forces.jpg
Normal Forces.jpg (261.8 KiB) Viewed 14023 times
thschrader
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Re: Request for help meshing and and analysing a part

Post by thschrader »

Here is a simple test case.
Buckling of a beam, L=2000 mm, Profile 10x100 mm rectangular, initial load 1000 N.
Computed are the first 2 modes:
mode1: FC=4,33 Mastan=4,30 buckling-factors
mode2: FC=17,45 Mastan=17,21
looks good in my opinion.
My commercial software pcae gives 4,0 as factor, due to design-manuals.

zip contains FC/Mastan/Smath files.
Have fun with buckling :mrgreen:
bucklingTest.zip
(102.56 KiB) Downloaded 250 times
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

cad1234 wrote: Thu Sep 09, 2021 2:27 pm @Laurie
here is a another MASTAN2 screenshot of the normal forces, you maybe might like ;) :
Yes very beautiful. not quite "a picture is worth a thousand words" but very informative. Colour is a very useful way of providing and enhancing information.
I haven't had much time to look into Mastan - I have been trying to absorb the information that has flowed through this thread. Can you establish the compression and tension forces of individual members in Mastan? Actually can we do that it in FreeCAD? That would be something.

@ Thomas - "buckling" - the scourge of the scaffold and formwork industry from which I came , along with wind loads. It is interesting for me viewing these screenshots and the pipeline outputs - If it makes sense I can "see" what they would look like in the outside world.

Well time for me to take a deep breath. I am going to prepare what I think might be a suitable check list for the structural integrity of this structure based on what I have learnt from this thread. I will post it in a couple of days time - this may be a source of amusement but as the saying goes -"you will never know if you don't have a go"

That exercise will no doubt result in more questions but one more before I go :D - Is there an output for the reactions at the points of support in FreeCAD?

Have a good weekend.
cad1234
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Re: Request for help meshing and and analysing a part

Post by cad1234 »

Laurie Hartley wrote: Sat Sep 11, 2021 6:18 am Can you establish the compression and tension forces of individual members in Mastan?
Yes, but letting all results be displayed on the screen looks a bit crowdy.
Here is a selective view.
You can also select each element / node to see the values eg. force, displacement, reaction force, node rotation etc.

However, as far as I see, FC-FEM can deliver the same results, in a great way with paraview.
Thomas knows much more about this than I do

BTW:
I understand this more as a quick results verification, with a different tool...from my point of view ...
Too many options, for wrong user inputs :D
Of course we are at an FC-FEM party !!!
Attachments
Normal Forces-values.jpg
Normal Forces-values.jpg (170 KiB) Viewed 13860 times
balrobs
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Re: Request for help meshing and and analysing a part

Post by balrobs »

Hi guys,
this is an amazing thread :o ... full of usefull informations and a beautifull example of how willing people can grow together.
Thank you all for making this possible!
Just for fun and to have another comparision I did the same buckling calculation in Code_Aster (I'm still learning this software).
Here are my results which BTW are in great accordance with what already was found:
Deformations
Deformations
deformation.jpg (238.26 KiB) Viewed 13773 times
Buckling mode - 3 segments per element
Buckling mode - 3 segments per element
buckling_mode1_3_segment_per_element.png (304.52 KiB) Viewed 13773 times
Buckling mode - 6 segments per element
Buckling mode - 6 segments per element
buckling_mode1_6_segment_per_element.jpg (350.94 KiB) Viewed 13773 times
Have a nice weekend :D
cad1234
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Re: Request for help meshing and and analysing a part

Post by cad1234 »

balrobs wrote: Sat Sep 11, 2021 12:56 pm
GREAT!!!
Have a nice weekend too!
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johnwang
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Re: Request for help meshing and and analysing a part

Post by johnwang »

Nodes
msh3.jpg
msh3.jpg (71.48 KiB) Viewed 13643 times
hfc series CAE workbenches for FreeCAD (hfcNastran95, hfcMystran, hfcFrame3DD, hfcSU2 and more)
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

balrobs wrote: Sat Sep 11, 2021 12:56 pm this is an amazing thread :o
Agreed, welcome to the thread and thank you for your contribution.

It appears to me that the input from other open source applications and Thomas’ commercial software is confirming the reliability and accuracy of FreeCAD FEM workbench.

@John you are a man of few words :) - is your screenshot saying that Mystran gives the information by member?
Also I noticed the numbering matrix of the nodes eg 1, 2, 3, & 4 “reads” 4, 3, 1, 2.
I now have Mystran in my Linux FreeCAD v20 weekly build - just got to figure out how to use it now!
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