Texture evolution during plastic deformation?

[MTEXNewbie]

Hi,

I noticed the texture evolution during rolling example code and have some questions - https://mtex-toolbox.github.io/files/doc/TaylorModel.html#13

1. Is this built-in function comparable to the VPSC method for texture evolution during plastic deformation?

2. What are the advantages and disadvantages of the MTEX approach?

3. The MTEX example code has it up to 0.30 strain, can we get texture evolution data at regular strain intervals (e.g. 0.1, 0.2, ... 0.5 etc.) to construct an animation?

4. Can I calculate the (average) Taylor factor from the resultant texture data (ori)?

5. Below is an example code I am using for uniaxial tension, is this correct?

% crystal symmetry

cs = crystalSymmetry('m-3m', [3.6599 3.6599 3.6599], 'mineral', 'Iron fcc', 'color', 'light blue');

% define some random orientations

ori = orientation.rand(10000,cs);

% plot the pole figures

figure

plotPDF(ori,Miller({1,1,1},cs),'contourf')

mtexColorbar

% 30 percent plane strain (Uniaxial Tensile)

q = 0.5;

epsilon = 0.3 * strainTensor(diag([-q -(1-q) 1]));

%

numIter = 10;

progress(0,numIter);

for sas=1:numIter

  % compute the Taylor factors and the orientation gradients

  [M,~,mori] = calcTaylor(inv(ori) * epsilon ./ numIter, sS.symmetrise,'silent');

  % rotate the individual orientations

  ori = ori .* mori;

  progress(sas,numIter);

end

% plot the resulting pole figures

figure

plotPDF(ori,Miller({1,1,1},cs),'contourf')

mtexColorbar

[Rüdiger Kilian]

Hi
a few answers.
wrt 1) No, Taylor adn VPSC models are not the same. Taylor assumes iso-strain. Depending on the situations results may be still similar or significantly different.

wrt 2) I'd say any advanges/disadvantages of one over the otehr depend on the assumptions you are making and what exactly you want to model.

wrt 3) Yes, just write the orientations for each step i to a variable e.g. o_out(:,i)=ori. Than you do whatever you like with those later on.

wrt 4) Maybe you need to specify a little more what you mean here. All in one step? Or the average Tayler factor for each orientation averaged over all steps? If the latter, just save all the Taylor factors to a n-by-i variable (similar to the orientations) and calculate the mean afterwards.

wrt 5) Depending on the definition of strain (tension is positive for many engineers, negative for geologists), it looks like you are pulling or pushing in the Z-direction.

Hope that helps.
Cheers,
Rüdiger

________________________________________
From: mtex...@googlegroups.com <mtex...@googlegroups.com> on behalf of MTEXNewbie <rashed...@gmail.com>
Sent: Thursday, July 12, 2018 6:34:30 PM
To: MTEX
Subject: {MTEX} Texture evolution during plastic deformation?

--
If you want to reduce the number of emails you get through this forum login to https://groups.google.com/forum/?fromgroups=#!forum/mtexmail, click "My membership" and select "Don't send me email updates". You can still get emails on selected topics by staring them.
---
You received this message because you are subscribed to the Google Groups "MTEX" group.
To unsubscribe from this group and stop receiving emails from it, send an email to mtexmail+u...@googlegroups.com<mailto:mtexmail+u...@googlegroups.com>.
Visit this group at https://groups.google.com/group/mtexmail.
For more options, visit https://groups.google.com/d/optout.

[MTEXNewbie]

Hi Rüdiger,

Thank you for the answers.

1. Would it be possible to recommend me some literature related to the model built-in MTEX?

2. Same as 1, I would like to know about the assumptions in the model.

3. Thank you for the tip, I will try it on and report back later.

4. Average Taylor factor in each step.

5. Yes, I am pulling it in Z-direction. It is the cross-sectional EBSD of a tensile sample, is this valid way to do this, or only RD/TD loading is valid?