iMechanica - Comments for "Yield surface of a material model"
https://www.imechanica.org/node/16511
Comments for "Yield surface of a material model"enElasto-viscoplastic model without explicit yield criteria
https://www.imechanica.org/comment/25846#comment-25846
<a id="comment-25846"></a>
<p><em>In reply to <a href="https://www.imechanica.org/node/16511">Yield surface of a material model</a></em></p>
<div class="field field-name-comment-body field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p>
<span>Dear Louie,</span><span></span>
</p>
<p>
<span>Thanks again. An elasto-viscoplastic model<br />
was developed based on single model Leonov model. This model is described in:</span><span></span>
</p>
<p>
<span><a href="http://mate.tue.nl/mate/pdfs/20.pdf">http://mate.tue.nl/mate/pdfs/20.pdf</a></span><span></span>
</p>
<p>
<span>The only way I can think of to plot the<br />
yield surface of the model is to conduct some numerical examples in different<br />
stress states. I was wondering if you, considering the model, could let me know<br />
if you have any other idea. I appreciate your concern.</span><span></span>
</p>
<p>
<span>Regads,</span><span></span>
</p>
<p>
<span>Mohsen</span><span></span>
</p>
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</ul>Wed, 07 May 2014 17:32:54 +0000Mirkhalafcomment 25846 at https://www.imechanica.orgperhaps if I could see the constitutive model it would help
https://www.imechanica.org/comment/25845#comment-25845
<a id="comment-25845"></a>
<p><em>In reply to <a href="https://www.imechanica.org/node/16511">Yield surface of a material model</a></em></p>
<div class="field field-name-comment-body field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p>
Hi Mohsen,
</p>
<p>
It would be helpful to see the constitutive model you are using. However, it seems like you must have some sort of criteria for a state of stress being on the yield surface or not. Even if this is an algorithmic criteria rather than an explicit formula, you still can algorithmically detect if a stress state is on the surface or not. (At least I'm assuming this is true.) I'm not sure why you would have to resort to a finite element analysis. If you have a sufficiently large grid at a sufficiently small spacing in principal stress space you should be able to detect which principal stress points (sigma 1, sigma 2, sigma 3) are on the surface. Maybe I'm not understanding your situation correctly, but I'd be willing to look at the model if you wish.
</p>
<p>
I hope this helps.
</p>
<p>
regards,
</p>
<p>
Louie
</p>
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</ul>Wed, 07 May 2014 15:58:30 +0000yawloucomment 25845 at https://www.imechanica.orgDear Louie,
Thank you for
https://www.imechanica.org/comment/25844#comment-25844
<a id="comment-25844"></a>
<p><em>In reply to <a href="https://www.imechanica.org/node/16511">Yield surface of a material model</a></em></p>
<div class="field field-name-comment-body field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p>
Dear Louie,
</p>
<p>
Thank you for your reply to my question. The thing is I am not using an explixit yield function for the FEM implementation. That is why, I am trying the capture the yield surface using FEM simulations. I guess, since the material model is isotropic, having axisymmetric simualtions (both tensile and compressive) and plane strain simuations (both tensile and compressive) and pure shear simulations will provide enough yiled points to draw the yield surface. What do you think?
</p>
<p>
Thanks again.
</p>
<p>
Regards,
</p>
<p>
Mohsen
</p>
<p>
</p>
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</ul>Wed, 07 May 2014 10:44:39 +0000Mirkhalafcomment 25844 at https://www.imechanica.orgHello,
If you have the
https://www.imechanica.org/comment/25841#comment-25841
<a id="comment-25841"></a>
<p><em>In reply to <a href="https://www.imechanica.org/node/16511">Yield surface of a material model</a></em></p>
<div class="field field-name-comment-body field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p>
Hello,
</p>
<p>
If you have the equation of the yield surface, you can just plot it in Matlab. I have done this for a 2D yield surface(my following description works for 3D also). A brute force method works. Just try lots of points and if they are on the yield surface within some tolerance epsilon, then you plot the point. If it is not close enough to the yield surface you don't plot the point. If you plot enough points eventually you will have a complete depiction of the yield surface. Finite element software is not required to do this.
</p>
<p>
<br />
regards,
</p>
<p>
Louie
</p>
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</ul>Wed, 07 May 2014 00:38:38 +0000yawloucomment 25841 at https://www.imechanica.orgTheoretical and Applied Mechanics - StackExchange
https://www.imechanica.org/comment/25837#comment-25837
<a id="comment-25837"></a>
<p><em>In reply to <a href="https://www.imechanica.org/node/16511">Yield surface of a material model</a></em></p>
<div class="field field-name-comment-body field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p>Try asking the question in the dedicated stackExchange site:<br /><a href="http://area51.stackexchange.com/proposals/67726/theoretical-and-applied-mechanics?referrer=73mdEQ3M_DdhwHImwznaBQ2">http://area51.stackexchange.com/proposals/67726/theoretical-and-applied-...</a></p>
<p>See the discussion here for more information on it:<br /><a href="http://imechanica.org/node/16427">http://imechanica.org/node/16427</a></p>
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</ul>Tue, 06 May 2014 12:26:13 +0000swimfarcomment 25837 at https://www.imechanica.org