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#1 2020-06-23 12:54:40

saharf
Member
Registered: 2020-03-24
Posts: 7

[SOLVED] Postprocess: stresses in model consisting of 3D & 2D elements

Hello everyone.

I am modelling a simple horizontal pipeline buried in a cube of soil. the pipeline is modeled with Quadrangle DKT elements and the soil is modeled via Netgen 1D-2D-3D. before getting to actual nonlinear analysis, I wanted to see whether the mesh and boundary conditions are OK or not, so I defined the soil as a linear elastic material and glued the pipeline to soil using LIASON_MAIL to run a simple model and check.

The model runs and gives the displacements, but I have trouble getting the stress results (including Von mises stress)  for both soil and pipeline.
I created another model of a pipeline alone, and had no trouble getting the stress results(I got confused a lot in the process, because I could not figure out the difference between the given options, but I succeeded at last).

as far as I know, the problem occurs because the model has both 2D and 3D elements, but I'm not sure. I have seen some posts about this problem but they did not help me and I didn't quite understand how to solve it.

Can anyone help me with this?

In addition to that, does anyone know how to find a step by step guide  through post-processing in code_aster? (PDF, Training Course, Videos, etc.; even if not free) that will help me save a lot of time for the next models.

Thank you all in advance.

Last edited by saharf (2020-06-30 08:30:43)

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#2 2020-06-24 08:14:40

saharf
Member
Registered: 2020-03-24
Posts: 7

Re: [SOLVED] Postprocess: stresses in model consisting of 3D & 2D elements

Using the book of Jean-pierre Aubry (from page 79, making a Higway sign) I managed to get the stresses in the elements I chose.

I had to create two different output files, one for 3D elements and one for 2D elements.

That works fine for me, but it would be better if it was possible to view the results of both element types in one file.

Special thanks to Mr. Aubry for his helpful book!

P.S: before creating two separate files, I tried to use the Group filter in Asterstudy to choose the elements I wanted to see the stresses in, but the output of this action was totally different from when I created two separate files, so I am guessing either I was using it wrong, or it is not supposed to do this.
If this option is not supposed to do this, then what is it for?

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#3 2020-06-24 14:01:57

dezsit
Member
Registered: 2012-06-27
Posts: 60
Website

Re: [SOLVED] Postprocess: stresses in model consisting of 3D & 2D elements

Hi,

you can manage it with one file, just put all your resulting fields (DKT,3D,...) into one IMPR_RESU.

Then in paraVis, open the resulting med twice (or more, depending on the study), and select your 3D fields on one of the result file, than the 2D fields on the other result file.
See the attached picture,
here you can see mech.rmed file opened twice (it is one file from one IMPR_RESU),
on the first file I selected the 3D results: reslin_SIEQ_NOEU from ComSup2 in the selection window on the left bottom,
then on the second file I selected the DKT results, here the TOP____SIEQ_NOEU 8which contains the equivalent stresses on the top side of my shell),
Then visualized both together (VMIS filed on both) with adjusting the scales.

You can do that for any kind of combination (eg with beams or what ever), just sometimes a good visualization requires more tweeking in paraVis.

Best regards,
dezsit


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#4 2020-06-30 08:33:09

saharf
Member
Registered: 2020-03-24
Posts: 7

Re: [SOLVED] Postprocess: stresses in model consisting of 3D & 2D elements

Thank you very much for your help!

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#5 2020-07-02 12:28:20

Johannes_ACKVA
Member
From: Ingenieurbüro für Mechanik, DE
Registered: 2009-11-04
Posts: 690
Website

Re: [SOLVED] Postprocess: stresses in model consisting of 3D & 2D elements

Saharf wrote:

does anyone know how to find a step by step guide  through post-processing in code_aster? (PDF, Training Course, Videos, etc.; even if not free)

Saharf,
we are actually developing Video Courses from our long-years-practiced professional Code-Aster courses.
The 1st course is our Code-Aster-Introduction (a comprehensive 5-days-course, see w ww.code-aster.de/seminars-training-detail/code-aster-introduction-19-23-october-2020.html) which will be available from August. Our courses are commercial

If you are interested then please contact us with your mail address on our website w ww.code-aster.de. We will then give you further information as soon as possible.

Of course, we d also be happy to meet you personally in our next course in Germany, 19 - 23 October 2020

Regards
Johannes_ACKVA

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