Local Dislocation Map

ripening phenomena, dislocations, grainboundary topology
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carldslater
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Local Dislocation Map

Post by carldslater » Mon Nov 08, 2021 5:35 pm

Hi All,

I am looking at implementing a local dislocation map into a REX model. I have created a .txt file for the initial grain size that is created from an EBSD image. However i am struggling with the file format of the rhoD. It is a VTK file. Could anyone help me to understand the structure of this and if a .txt of the dislocation density can be used instead? (ive tried with no success).

Any help would be appreciated.

Carl Slater

ralph
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Re: Local Dislocation Map

Post by ralph » Mon Nov 08, 2021 5:49 pm

Hi Carl,

have a look at the example T11_04_ReXLocalRecovery.
https://micress.rwth-aachen.de/download.html#examples

The used VTK for dislocation densities are given in a ASCII format.
The only trapfall may be to give the DIMENSION in number of corners, not as number of cells.

Best regards,
Ralph

carldslater
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Re: Local Dislocation Map

Post by carldslater » Tue Nov 09, 2021 9:39 am

Many thanks for getting back to me.

The structure of these files seems to be in 9 columns. Is that a requirement? Do you know if these files are read left to right in rows, or if they are read vertically one column at a time? Just so it can help me reconstruct the file in the right shape.

Thanks again

ralph
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Re: Local Dislocation Map

Post by ralph » Tue Nov 09, 2021 10:02 am

The data input loop is Z-Y-X, i.e. the inner most loop iterates over the cells in X direction.

See also the training tutorial 'importing inital grain structures' on the 2nd day. The VTK format explained for grain structures is the same as for dislocation densities. Grain IDs or densities are both scalar data fields.
https://micress.rwth-aachen.de/basic-training-2021.html

Best regards,
Ralph

carldslater
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Re: Local Dislocation Map

Post by carldslater » Tue Nov 09, 2021 12:58 pm

This is really useful. thank you.

I tried using a .txt file as the input and got this error

Allocation error for array: Input_Field, in routine initFeldVonDatei !
requested dimension = 1 !
allocated dimension = 0 !

Do you know what the error refers to please?

The txt file is a matrix 200x200 the same as the setup. Does it need to be delimited with a space rather than a comma ?

ralph
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Re: Local Dislocation Map

Post by ralph » Tue Nov 09, 2021 4:46 pm

The wrong separator could be the problem.
Usually, we use a space separator. I never tested this with a comma.

Ralph

ralph
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Re: Local Dislocation Map

Post by ralph » Tue Nov 09, 2021 5:30 pm

I checked newest version 7.1 and found a bug in these input routines.
2D ASCII input for dislocation densities might not work at all.

Do you get mean recristallisation energies of zero for all grains afterwards? This would mean your version has the same bug.

I recommend to use a VTK in ASCII format. This should work.

Ralph

carldslater
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Re: Local Dislocation Map

Post by carldslater » Tue Nov 09, 2021 6:28 pm

Hi,

I am still using v6.4.

It doesnt let me get past that error so i dont get to see the REX energies.

I will also endeavor to convert my matrix to an ascii vtk but i am not having much success at the moment.

Thank you

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