Initial microstructure

ripening phenomena, dislocations, grainboundary topology
shaojielv
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Initial microstructure

Post by shaojielv » Sun Aug 29, 2021 1:47 pm

Hi,
I would like to ask some questions about the MICRESS, because I want to do solid state phase transition, but for the initial structure we want to get through our own calculation, for example, the austenite structure after rolling, I want to use the rolled structure as the initial structure of solid state phase transition, and then do the subsequent calculation. In this case, can MICRESS be implemented? If so, what kind of file should be use? I am looking forward to your reply and will be greatly appreciated.
Finally, I wish you a happy life and smooth work.
lvshaojie.

Bernd
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Re: Initial microstructure

Post by Bernd » Mon Aug 30, 2021 10:52 am

Dear shaojielv,

The simplest and best way to achieve that in MICRESS is by using the restart files (.rest) as source for the microstructure of the previous simulation run. The use of restart files has been explained in detail here. Please note that reading restart files as a source for initial microstructures has in former times been handled by the restart suboption "structure_only", but now (since Version 7.0) has been shifted to the section "Initial Microstructure/Structure from restart file".

Bernd

shaojielv
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Re: Initial microstructure

Post by shaojielv » Mon Aug 30, 2021 2:01 pm

Dear Bernd,
First of all, I am very glad to receive your reply again. In addition, I would like to further explain my question. Because the simulation I want to do is not just start the solid phase transition as soon as the solidification is over. What I want to do is do a cross-scale simulation, which is the rolling process that I mentioned here. We directly rolled the as-cast structure after solidification, that is, after recrystallization, we studied the solid phase transformation. Therefore, I needed to transfer data, that is, I said, I took the recrystallized grain as my initial structure. May I ask whether the data generated in this process can be imported into the MICRESS as I need? I hope to get your further explanation if possible. So the restart file here is not what I want.
Looking forward to your reply.
shaojielv

shaojielv
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Re: Initial microstructure

Post by shaojielv » Mon Aug 30, 2021 2:29 pm

Or: for the initial organization we need in this software, in addition to the restart files of the software itself, can we use the exported data of other software as our initial organization?

Bernd
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Re: Initial microstructure

Post by Bernd » Mon Aug 30, 2021 6:13 pm

Dear shaojielv,

If you want to use a different software for simulation of rolling, then the results are in a different format, and you cannot use the method with the .rest file. Instead, you can read the microstructure from an image file, as if it were an experimental microstructure. This has been discussed e.g. within this thread. I summarized the format requirements here. The grain properties (like phase number, orientation and recrystallisation energy) then can be added from a text file.

Bernd

shaojielv
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Re: Initial microstructure

Post by shaojielv » Tue Aug 31, 2021 3:32 pm

Dear Bernd,

First of all, thank you for your reply. I have learned a lot from your reply. In the follow-up study, I will further practice the methods you mentioned. If possible, I hope to get the Perl script PGM_ to_ MICRESS. I will be very grateful.

Thanks.

LV Shaojie

Bernd
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Re: Initial microstructure

Post by Bernd » Tue Aug 31, 2021 4:16 pm

Dear LV Shaojie,

Sorry, I did not mention that the script is located in the "Tools" directory of your MICRESS installation.

Bernd

ralph
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Re: Initial microstructure

Post by ralph » Mon Sep 06, 2021 11:36 am

see also newest MICRESS training (day 2):
https://micress.rwth-aachen.de/basic-tr ... 21.08.html

Best,
Ralph

hariharanVS
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Re: Initial microstructure

Post by hariharanVS » Sat Feb 26, 2022 1:59 pm

Bernd wrote:
Mon Aug 30, 2021 10:52 am
Dear shaojielv,

The simplest and best way to achieve that in MICRESS is by using the restart files (.rest) as source for the microstructure of the previous simulation run. The use of restart files has been explained in detail here. Please note that reading restart files as a source for initial microstructures has in former times been handled by the restart suboption "structure_only", but now (since Version 7.0) has been shifted to the section "Initial Microstructure/Structure from restart file".

Bernd
Hi Bernd,
I am trying to achieve the same which you mentioned in the above post, using version 7.1. I have mentioned the restart file name in restart section. What option should I use in Initial Microstructure section to take input from .rest file?

Bernd
Posts: 1504
Joined: Mon Jun 23, 2008 9:29 pm

Re: Initial microstructure

Post by Bernd » Sat Feb 26, 2022 7:57 pm

Dear hariharanVS,

Welcome to the MICRESS forum!

Already in MICRESS Version 7.0 we reorganized the input and separated the normal "restart" function (i.e. continue a stopped simulation) from the input of an initial microstructure based on one or more .rest-files.

The latter function now is located in section "Initial Microstructure" / "Structure from restart file" of the driving file, which, we believe, is much more intuitive for the user. The basic idea is (as before), that based on the a user-defined initial microstructure, each grain region can be replaced by the content of a restart file. In the simplest case (without initial grain input) you should select grain 0 for replacement, which is there always by default.

If you define several grains as "place holder", you can read several .rest files and combine microstructures, or just read one for combining the microstructure from restart with other initial microstructures you defined manually or have read from ASCII or VTK files, e.g.

# Initial Microstructure
# ======================
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
deterministic
# NB: the origin of coordinate system is the bottom left-hand corner,
# all points within the simulation domain having positive coordinates.
# Number of grains at the beginning?
2
#
# Grain number 1
# --------------
# Geometry?
# Options: round rectangular elliptic round_inverse
...
#
# Grain number 2
# --------------
# Geometry?
# Options: round rectangular elliptic round_inverse
...
#
# Structure from restart file
# ---------------------------
# Shall grain(s) be replaced by initial structure(s) from a restart file(s) ?
# Options: restart_file | no_restart_file
restart_file
# How many restart files shall be read?
1
# For each restart file, a grain number and (optionally)
# shift (in grid cells) and zoom factor for all 3 dimensions
# as well as a character for rotation options must be specified:
# grain number [shift X (int) shift Y (int) shift Z (int)
# zoom X (int) zoom Y (int) zoom Z (int) rot(string)] ?
# Rotation options: "xz+90" "xz-90" "xz180" "xy+90" ... "yz180"
2 0 0 -4000
# Name of restart file?
test_r
#

Bernd

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