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defining variables for postprocessing

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Hi there,

I'm simulating stress fields in thermally treated material. I'm especially interested in shear stresses in different directions in the model. So what I do is to mathematically rotate the stress tensor directly in the plot. The problem is, that I have to change the angle in many different places to generate the plot I want. I.e. I want to rotate the stress tensor 30° then I have to access three different fields changing a total of 8 variables to that angle.

I was wondering if there was an easier way to do this. For instance, is there a way to define a post processing variable that I can input into the fields, then I just would need to change that variable once instead of 8 times. And the plot would update much faster. Is there any way to do this?

Best,
Martin

2 Replies Last Post 31 janv. 2012, 03:47 UTC−5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 30 janv. 2012, 10:07 UTC−5
Hi

unfortunately there is no good way (at least that I know about) to reformat Results variables in other coordinate frames (without writing out everything ;(
One thing that does partially work: you define a coordinate frame of generic type, you write out 3-6-9 equations with this cooridnate transform as variables, you solve and you plot. Then if you change the reference coordinate, You can resolve or update the solution (without resolving fully) and replot the same variables in the new reference frame

I would propose that you too, send a suggestion to support for some further enhacement in this direction, when we are amyn enough, with valid arguments, our suggestions do get implemented ;)

--
Good luck
Ivar
Hi unfortunately there is no good way (at least that I know about) to reformat Results variables in other coordinate frames (without writing out everything ;( One thing that does partially work: you define a coordinate frame of generic type, you write out 3-6-9 equations with this cooridnate transform as variables, you solve and you plot. Then if you change the reference coordinate, You can resolve or update the solution (without resolving fully) and replot the same variables in the new reference frame I would propose that you too, send a suggestion to support for some further enhacement in this direction, when we are amyn enough, with valid arguments, our suggestions do get implemented ;) -- Good luck Ivar

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Posted: 1 decade ago 31 janv. 2012, 03:47 UTC−5
Hi Ivar,

Thanks a lot for the answer. I think I found another solution: accessing the parameter by Matlab, witch will automatically export all tables and plots for all rotations I wish.

Anyway, here a follow up question:

I work a lot with the stress tensor element ts.syz. In according to mechanics this would denote a stress in z-direction on a plane with surface normal in y-direction, right? Does Comsol use the same definition? Where could I find this in the Comsol documentation?

Best,
Martin
Hi Ivar, Thanks a lot for the answer. I think I found another solution: accessing the parameter by Matlab, witch will automatically export all tables and plots for all rotations I wish. Anyway, here a follow up question: I work a lot with the stress tensor element ts.syz. In according to mechanics this would denote a stress in z-direction on a plane with surface normal in y-direction, right? Does Comsol use the same definition? Where could I find this in the Comsol documentation? Best, Martin

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