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stress analysis in a two dimesion system

Posted 2015年8月6日 GMT+8 17:57 Structural Mechanics 5 Replies

Md Sayeedur Rahman
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Hi all,

5 Replies Last Post 2017年3月12日 GMT+8 17:45
Lasse Murtomäki
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Posted: 1 decade ago 2015年8月7日 GMT+8 13:49
Hi

I looked at your model and do not quite understand it. I suppose that in the alloy you have several phases but still only one diffusing species, oxygen. Then you do not need separate tds nodes for each phase, it is sufficient to define the diffusivity of oxygen in them. By variables c2...c7 you probably mean the oxygen concentrations in those phases? Or what are they?

Anyway, diffusion in the solid phase is extremely slow. You have given even values of 1e-50 m²/s in some phases. This means that diffusing 1 µm would take 10^38 s = 3·10^30 years while our universe is ca. 13.8·10^9 years old :) If D = 1e-17 m²/s, in 1000 hours diffusion proceeds ca. 6 µm.

So, what to do: Under one single Transport of Diluted Species (tds) node, define the diffusion coefficient in each domain, nothing else.

BR
Lasse
Hi I looked at your model and do not quite understand it. I suppose that in the alloy you have several phases but still only one diffusing species, oxygen. Then you do not need separate tds nodes for each phase, it is sufficient to define the diffusivity of oxygen in them. By variables c2...c7 you probably mean the oxygen concentrations in those phases? Or what are they? Anyway, diffusion in the solid phase is extremely slow. You have given even values of 1e-50 m²/s in some phases. This means that diffusing 1 µm would take 10^38 s = 3·10^30 years while our universe is ca. 13.8·10^9 years old :) If D = 1e-17 m²/s, in 1000 hours diffusion proceeds ca. 6 µm. So, what to do: Under one single Transport of Diluted Species (tds) node, define the diffusion coefficient in each domain, nothing else. BR Lasse
Lasse Murtomäki
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Posted: 1 decade ago 2015年8月7日 GMT+8 15:21
Here my solution. You may correct what I had there wrong.

BR
Lasse
Here my solution. You may correct what I had there wrong. BR Lasse

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Md Sayeedur Rahman
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Posted: 1 decade ago 2015年8月10日 GMT+8 21:33
Thanks
Thanks

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Lasse Murtomäki
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Posted: 1 decade ago 2015年8月10日 GMT+8 22:26
OK

Your model is much more complicated that oxygen diffusion. I am afraid I am not able to help you.

BR
Lasse
OK Your model is much more complicated that oxygen diffusion. I am afraid I am not able to help you. BR Lasse
Donovan Wang
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Posted: 9 years ago 2017年3月12日 GMT+8 17:45
Hi Rahman
I am very interested in the geometry of your model. And I'm wondering if you could tell me something about the interior boundaries inside of the substrate metal, was randomly generated by a software or drawn manually by CAD?

Thank you
Xiaokang
Hi Rahman I am very interested in the geometry of your model. And I'm wondering if you could tell me something about the interior boundaries inside of the substrate metal, was randomly generated by a software or drawn manually by CAD? Thank you Xiaokang

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