FEM Reinforcement Results Comparing FreeCAD to Code Aster

About the development of the FEM module/workbench.

Moderator: bernd

User avatar
hhassey
Posts: 160
Joined: Thu Jun 04, 2015 8:01 pm
Location: Ensenada, Mexico

FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by hhassey » Thu Aug 06, 2020 2:14 am

As I promised I ran a the FreeCAD Reinforcement RC Wall 2D example in Code Aster to compare the results. I hope this effort is useful for someone.

First I need to point out the following things:
  • Of course both have the same geometry, same mesh, loading and boundary conditions.
  • The Reinforced Material used in FreeCAD was made out of Concrete-EN-C35/45 for the matrix and Reinforcement-FIB-B500 for the steel.
    I was expecting the concrete to have a compressive strength of 30 MPA or 45MPA to my surprise it was set at 15.75 MPA (maybe someone should revise this number)
  • Second, in Code Aster. There are far more parameters to use, there is a safety factor for the steel stress and one for the concrete stress, I set both to 1.
  • Code aster calculates two layers of steel i.e Upper and lower steel. over the thickness of the shell, in this case both have the same stress and thus both results in code aster need to be added.
  • Code aster reports it's reinforcement in m2 / m so in order to compare to the Reinforcement Ratio of FreeCAD I had to divide Code Aster result by 0.15m (the thickness of the shell)
Here are the Results:
FreeCAD:
FreeCAD Reinforcement.jpg
FreeCAD Reinforcement.jpg (39.81 KiB) Viewed 772 times
Code-Aster:
Aster Reinforcement.jpg
Aster Reinforcement.jpg (60.07 KiB) Viewed 772 times
User avatar
bernd
Posts: 10956
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by bernd » Thu Aug 06, 2020 3:56 am

the colorbars seam sligthly different, but the result values seam equal ... :D
User avatar
bernd
Posts: 10956
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by bernd » Thu Aug 06, 2020 3:57 am

did you use the same mesh for both?
User avatar
hhassey
Posts: 160
Joined: Thu Jun 04, 2015 8:01 pm
Location: Ensenada, Mexico

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by hhassey » Thu Aug 06, 2020 4:00 am

bernd wrote:
Thu Aug 06, 2020 3:56 am
the colorbars seam sligthly different, but the result values seam equal ... :D
That was the most similar I could find in CA.

And yes, I used the same mesh on both cases.
User avatar
bernd
Posts: 10956
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by bernd » Thu Aug 06, 2020 10:44 am

Since the same mesh was used, the nodal values could compared as well. Is it possible to print nodal values out of code aster? With an export from FreeCAD to Paraview this should be possible from FreeCAD side.
User avatar
hhassey
Posts: 160
Joined: Thu Jun 04, 2015 8:01 pm
Location: Ensenada, Mexico

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by hhassey » Thu Aug 06, 2020 6:20 pm

Can you outline the process of exporting from FreeCAD to Paraview?
david69
Posts: 368
Joined: Wed Jan 01, 2014 7:48 pm

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by david69 » Thu Aug 06, 2020 6:27 pm

User avatar
hhassey
Posts: 160
Joined: Thu Jun 04, 2015 8:01 pm
Location: Ensenada, Mexico

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by hhassey » Thu Aug 06, 2020 8:34 pm

Here are the calculated displacements.

FreeCAD:
Displacement_Fc.png
Displacement_Fc.png (54.16 KiB) Viewed 638 times

Code-Aster:
Displacement_ca.png
Displacement_ca.png (49.62 KiB) Viewed 638 times
User avatar
bernd
Posts: 10956
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by bernd » Fri Aug 07, 2020 10:12 am

hhassey wrote:
Thu Aug 06, 2020 6:20 pm
Can you outline the process of exporting from FreeCAD to Paraview?
- In FEM workbench
- select the std FEM Result object
- Menue File --> export --> file typ --> FEM result VTK --> put in a name and press ok
- open the exported vtk file in Paraview :)
User avatar
bernd
Posts: 10956
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: FEM Reinforcement Results Comparing FreeCAD to Code Aster

Post by bernd » Fri Aug 07, 2020 10:15 am

seams we (HarryvL) did a good job ... :D He was the one who initially developed the reinforcement force calculation.
Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 4 guests