Yade

Questions about Force Chain output from Yade

Asked by Fu zuoguang

Dear Prof. Chareyre and all users:
Thanks for your last help. Today my question is just about outputting the Force Chain results from Yade.
As you known, Force Chain, which is accumulated by a series of interaction forces produced by their respective contact physics at the unique point, is always determined as one of the most important link between the micro-level attributes and the macro-level responses. In order to pay attention to its evolution, I want to output the result of force chain in each determined steps from Yade rather than just get its final state using the ‘openGL rendering’ in display interface after the running is finished. So my questions are:
(1) Are there any examples in Yade now can bring the direct solution to me about this question?
(2) If not (Yade now cannot output the Force Chain data directly in Yade’s interface), I need to display it in some other third party post-process software with my own python codes. This task may start at outputting all the contact information in each desired step, The pseudo-codes are followed:

In the desired step:
    For contact in all contacts:
        Output contact_point_id;
        Output contact_point_coordinates_list[x,y,z];
        Output contact_varibles_list[3Dof or 6Dof in local coordinate]

So, I want to confirm the practicability of the above details and want to ask you that can all the ‘output’ operations above be executed in yade? And which class can bring the possibility? (ScGeom or ScGeom6D)

Seeking your help!

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Klaus Thoeni (klaus.thoeni) said : 		#1

Hi,

you can directly plot force chains in yade (just lines) or in paraview (with color code). Have a look at [1] and [2].

HTH
Klaus

[1] https://answers.launchpad.net/yade/+question/212885
[2] https://answers.launchpad.net/yade/+question/213442

Revision history for this message
Fu zuoguang (zgfu1985) said : 		#2

Dear Thoeni:

Thanks for your suggestion. As Prof. Chareyre mentioned in 2# of question/212885, there is an easy way to plot the force chain directly in Yade as:

yade.qt.Renderer().shape=0 (conceal the spherical bodies in Yade screen)
yade.qt.Renderer().intrPhys=1 (show the force net only)

But this way is not flexible enough since it cannot add some necessary elements in post-processing (such as ‘legend’ mentioned later). So, choosing Paraview as the third-party software is a good idea. But as a new student of Paraview, I now miss some basic concepts of its usage:

The basic data format of .txt from Yade is ‘x, y, z, r, attributes’, but I am not sure that this type of ASCII format can directly recognized by Paraview. If not, this format should be transformed into a standard VTK form, the format and the extension of it are what?

Seeking your help!

Revision history for this message
Jan Stránský (honzik) said : 		#3

Hi Fu,

instead of txt export, you can use direct export to vtk format, either
using VTKRecorder [1] or VTKExporter [2]. There are some scripts in
yade/examples directory. You can find it by linux commands

cd /path/to/yade/examples
grep -R VTKRecorder .
grep -R VTKExporter .

Alternatively you can export data from Yade in any file format (possibly
exported by your own function) and create your own converting script to vtk
legacy format [3].

cheers
Jan

[1] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.VTKRecorder
[2] https://yade-dem.org/doc/yade.export.html#yade.export.VTKExporter
[3] http://www.vtk.org/wp-content/uploads/2015/04/file-formats.pdf

2015-05-06 10:56 GMT+02:00 Fu zuoguang <<email address hidden>
>:

> Question #266460 on Yade changed:
> https://answers.launchpad.net/yade/+question/266460
>
> Status: Answered => Open
>
> Fu zuoguang is still having a problem:
> Dear Thoeni:
>
> Thanks for your suggestion. As Prof. Chareyre mentioned in 2# of
> question/212885, there is an easy way to plot the force chain directly
> in Yade as:
>
> yade.qt.Renderer().shape=0 (conceal the spherical bodies in Yade screen)
> yade.qt.Renderer().intrPhys=1 (show the force net only)
>
> But this way is not flexible enough since it cannot add some necessary
> elements in post-processing (such as ‘legend’ mentioned later). So,
> choosing Paraview as the third-party software is a good idea. But as a
> new student of Paraview, I now miss some basic concepts of its usage:
>
> The basic data format of .txt from Yade is ‘x, y, z, r, attributes’, but
> I am not sure that this type of ASCII format can directly recognized by
> Paraview. If not, this format should be transformed into a standard VTK
> form, the format and the extension of it are what?
>
> Seeking your help!
>
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>
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