Hi All
i'm trying to do static analysis (with force and fixed constraint on sides)
in Previous version of FreeCAD i could see Stress Values along with displacement in CCX_Results
but now i see only displacement, Stress is always zero on all the faces (tried with different materials, but no effect on result)
although i can see min and max values for Stress in CCX_Result but in color gradient its zero on entire model
Since attachment file size limit is 1mb, FreeCAD file can be found here
Is it something to do with latest version of FreeCAD or FEM solver settings?
Freecad Version: 0.19
Revision Number: 24291 (Git)
Thanks for your time.
with warm regards,
Prakash
FEM Stress values are not showing
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Re: FEM Stress values are not showing
FEM solver needs a mesh satisfying some quality standards to get a valid solution.
Tetrahedrons should have a maximum aspect ratio of 2.
That means if you consider a profile thickness of 2 mm, mesh element size should not exceed 4 mm.
Furthermore model defeaturing is a major task in your workflow and shouldn't be skipped.
All these tiny arc has to be removed before engaging a mesher.
This gives using gmsh_4.8.4:
========================== Dump contents of mesh ==========================
1) Total number of nodes: 488861
2) Total number of edges: 15066
3) Total number of faces: 160078
4) Total number of polygons: 0
5) Total number of volumes: 248750
6) Total number of polyhedrons: 0
7) Total number of linear edges: 0
8) Total number of linear faces: 0
9) Total number of linear volumes: 0
10) Total number of quadratic edges: 15066
11) Total number of quadratic faces: 160078
11.1) Number of quadratic triangles: 160078
11.2) Number of quadratic quadrangles: 0
12) Total number of quadratic volumes: 248750
12.1) Number of quadratic hexahedrons: 0
12.2) Number of quadratic tetrahedrons: 248750
12.3) Number of quadratic prisms: 0
12.4) Number of quadratic pyramids: 0
===========================================================================
Solving with ccx_2.17_PARDISO.dhondt.exe gives:
used versions:
gmsh 4.8.4
ccx_2.17_PARDISO.dhondt.exe
OS: Windows 10 (10.0)
Word size of FreeCAD: 64-bit
Version: 0.20.24893 (Git)
Build type: Release
Branch: master
Hash: 03855f793feaceeb4385c02f6520f3e1b6429c93
Python version: 3.9.4
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: German/Germany (de_DE)
Tetrahedrons should have a maximum aspect ratio of 2.
That means if you consider a profile thickness of 2 mm, mesh element size should not exceed 4 mm.
Furthermore model defeaturing is a major task in your workflow and shouldn't be skipped.
All these tiny arc has to be removed before engaging a mesher.
This gives using gmsh_4.8.4:
========================== Dump contents of mesh ==========================
1) Total number of nodes: 488861
2) Total number of edges: 15066
3) Total number of faces: 160078
4) Total number of polygons: 0
5) Total number of volumes: 248750
6) Total number of polyhedrons: 0
7) Total number of linear edges: 0
8) Total number of linear faces: 0
9) Total number of linear volumes: 0
10) Total number of quadratic edges: 15066
11) Total number of quadratic faces: 160078
11.1) Number of quadratic triangles: 160078
11.2) Number of quadratic quadrangles: 0
12) Total number of quadratic volumes: 248750
12.1) Number of quadratic hexahedrons: 0
12.2) Number of quadratic tetrahedrons: 248750
12.3) Number of quadratic prisms: 0
12.4) Number of quadratic pyramids: 0
===========================================================================
Solving with ccx_2.17_PARDISO.dhondt.exe gives:
used versions:
gmsh 4.8.4
ccx_2.17_PARDISO.dhondt.exe
OS: Windows 10 (10.0)
Word size of FreeCAD: 64-bit
Version: 0.20.24893 (Git)
Build type: Release
Branch: master
Hash: 03855f793feaceeb4385c02f6520f3e1b6429c93
Python version: 3.9.4
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: German/Germany (de_DE)
Re: FEM Stress values are not showing
files:
(mesh and result object stripped)
(mesh and result object stripped)
Re: FEM Stress values are not showing
Thanks for Detailed Answer.
Did you manually removed all those tiny arcs(fillets) or can we do it by macro(python)
There is an option (Decimation) in Mesh Design Workbench..but this option removed large faces instead of flattening the fillets.
Thanks Again
with warm regards,
Prakash
Did you manually removed all those tiny arcs(fillets) or can we do it by macro(python)
There is an option (Decimation) in Mesh Design Workbench..but this option removed large faces instead of flattening the fillets.
Thanks Again
with warm regards,
Prakash
Re: FEM Stress values are not showing
Prakash, please mark a thread [Solved] by prepending it to the title of the first post of this thread. Thanks
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Please mark thread [Solved]
Want to contribute back to FC? Checkout:
'good first issues' | Open TODOs and FIXMEs | How to Help FreeCAD | How to report Bugs
Please mark thread [Solved]
Want to contribute back to FC? Checkout:
'good first issues' | Open TODOs and FIXMEs | How to Help FreeCAD | How to report Bugs
Re: FEM Stress values are not showing
Yes, I used QCAD working on exported dxf file.
If you prefer working on extruded solid, please have a look at:
https://wiki.freecadweb.org/Part_Defeaturing