OpenSees, the Open System for Earthquake Engineering Simulation

[shahram10715]

Is it possible to output results in vtk format?

Not directly with Opensees. Maybe the following link can help:
https://github.com/lge88/opensees-vtk

[bernd]

https://github.com/berndhahnebach/FreeCAD_bhb/commits/femopensees only implements the solver object.

• start FreeCAD
• add analysis, delete standard solver and add a OpenSees solver
• run the solver
• this file will be written and run with OpenSees https://github.com/berndhahnebach/FreeCAD_bhb/blob/77ab5fbbd062139cab7024a9378fe240a690d7de/src/Mod/Fem/femsolver/opensees/writer.py#L82-L244

AS stated before see https://github.com/berndhahnebach/FreeCAD_bhb/commits/femoofem

[ebrahim_raeyat]

direct .tcl file link

if I run this file in OpenSees I get …

hugo@Ahorn:~/bin$ OpenSees Example8.1.tcl 


    while executing
"recorder plot Node.out CenterNodeDisp 625 10 625 450 -columns 1 2"
    (file "Example8.1.tcl" line 90)
hugo@Ahorn:~/bin$

and an empty file Node.out as well as a 10.0 MegaByte file gmon.out is created. -1 seams something went wrong ?

yes, please comment this line, i don’t know why that line not work.

[ebrahim_raeyat]

Is it possible to output results in vtk format?

I think it is possible, I had been see an example for vtk, I will search for it:

https://github.com/OpenSees/OpenSees/blob/master/SRC/recorder/VTK_Recorder.cpp

[bernd]

Is it possible to output results in vtk format?

I think it is possible, I had been see an example for vtk, I will search for it:

https://github.com/OpenSees/OpenSees/blob/master/SRC/recorder/VTK_Recorder.cpp

With this we could read results into FreeCAD directly. That would be cool and worth to search for.

[ebrahim_raeyat]

With this we could read results into FreeCAD directly. That would be cool and worth to search for.

opensees can export to .pvd format that supported with paraview:

this brief file is also useful:

http://marcel-ritter.com/wp-content/uploads/2016/10/FEMOpenSeesPoster.pdf

[ebrahim_raeyat]

thanks to openseespy, we can write opensees input file in python format and benefit from all of python library!

https://openseespydoc.readthedocs.io/en/latest/

[bernd]

I wonder if we shold.not even start with TCL input file format and imediately use the new python input fole format?

[bernd]

The same as in tcl, examples to get started are needed. Best would be freecad fem calculix cantilever in opensees python.

[shahram10715]

https://github.com/berndhahnebach/FreeCAD_bhb/commits/femopensees only implements the solver object.

• start FreeCAD
• add analysis, delete standard solver and add a OpenSees solver
• run the solver
• this file will be written and run with OpenSees https://github.com/berndhahnebach/FreeCAD_bhb/blob/77ab5fbbd062139cab7024a9378fe240a690d7de/src/Mod/Fem/femsolver/opensees/writer.py#L82-L244

AS stated before see https://github.com/berndhahnebach/FreeCAD_bhb/commits/femoofem

a file (src/Mod/Fem/Gui/Workbench.cpp) has been changes should we compile it from the beginning? would you please give more information about this post?

[bernd]

yes you need to compile FreeCAD because of the few lines change in workbench.cpp These lines add a new menue entry for the new FreeCAD FEM solver object for OpenSees.

The code I added adds this new object. With this the solver object is implemented. Now it would be the task to implement a opensees writer which does writes an opensees inputfile out of the FreeCAD FEM objects.

[Kunda1]

@Kunda1
Recently I wanted to put opensees binary as ppa in ubuntu launchpad but it’s not possible because you can only add FREE software. We must find a place which allows both free and proprietary software. The second option is an interesting repo on github (if you search you will find it) which has Docker for opensees ver 2.5 (not continued). And the third option is an appimage like FreeCAD.

Maybe a conda repository ?

[ebrahim_raeyat]

The same as in tcl, examples to get started are needed. Best would be freecad fem calculix cantilever in opensees python.

@bernd, i searched for equivalent Ten-node tetrahedral element for opensees, but i can’t find it.
for preparing 3D contilever, how can i change the element type in FreeCAD, for example one that had been used in original example in calculix site:
C3D20 http://web.mit.edu/calculix_v2.7/CalculiX/ccx_2.7/doc/ccx/node29.html

command for this element in opensees:

[bernd]

I would not care about the element type ATM. If opesees uses a twenty node brick element it will be fine too. It does not mater which element type we gone use. Both should give the nearly same deflection and stress if we use enought elements.

ATM it is not possible to make a brick20 mesh with the gui in FreeCAD but I will create one for the calculix cantilever.

[bernd]

find a file in this topic, but something is wrong with the brick20.

We will find and fix the problem

https://forum.freecadweb.org/viewtopic.php?f=18&t=43727

[ebrahim_raeyat]

I would not care about the element type ATM. If opesees uses a twenty node brick element it will be fine too. It does not mater which element type we gone use. Both should give the nearly same deflection and stress if we use enought elements.

ATM it is not possible to make a brick20 mesh with the gui in FreeCAD but I will create one for the calculix cantilever.

yes, I know, but it is imposible for me to create nodes and elements for this problem by hand, but if freecad can generate .inp input file, i can convert nodes and element from calculix format to opensees

[ebrahim_raeyat]

https://github.com/berndhahnebach/FreeCAD_bhb/commits/femopensees only implements the solver object.

• start FreeCAD
• add analysis, delete standard solver and add a OpenSees solver
• run the solver
• this file will be written and run with OpenSees https://github.com/berndhahnebach/FreeCAD_bhb/blob/77ab5fbbd062139cab7024a9378fe240a690d7de/src/Mod/Fem/femsolver/opensees/writer.py#L82-L244

AS stated before see https://github.com/berndhahnebach/FreeCAD_bhb/commits/femoofem

finally I did this procedure for the first time, hurray
it’s work, very excited.
thanks @bernd, now i will start to implement writer

[bernd]

best would be start with result reading. ATM on any solver run of OpenSees in FreeCAD this input file will be written

https://github.com/berndhahnebach/FreeCAD_bhb/blob/femopensees/src/Mod/Fem/femsolver/opensees/writer.py#L82-L244

ATM mesh is created by OpenSees, which is fine ATM, IMHO.

The first thing what we should do is change this input file in a way it creates some output in a format readable by vtk toolkit. If this works I would implement result reading in FreeCAD for OpenSees. Than we could start with the writer.

[shahram10715]

Maybe a conda repository ?

I’m not quite sure but I think it is dedicated to python packages only.

[shahram10715]

thanks to openseespy, we can write opensees input file in python format and benefit from all of python library!

https://openseespydoc.readthedocs.io/en/latest/

Its a good choice but we must consider that this package is not published open source yet.