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Problems open mph model constructed in version 3.5a in Version 4.0 ?

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Hi!

I have a question regarding how to open mph model constructed in version 3.5a in Version 4.0 ?

Especially if I have some self-defined expressions and also constants defined in version 3.5 model?
Seems when I use version 4.0 to open the model, it ignores the expressions or couldn't recognize it.

Is there anyway to go around this?
Thanks a lot.

LI

5 Replies Last Post 23 giu 2010, 05:56 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 18 giu 2010, 07:53 GMT-4
Hi

unfortunately not everything is imported correctly, I usually open a3.5 session as a reader, and then I rebuild my models in V4, as many things have changed, I learn more "how to" like that. But often its usefull to open first an old model to see where COMSOL stores old data to better know where to define the things when you seem to have several choices in V4. AS some are better than others

Have fun Comsoling
ivar
Hi unfortunately not everything is imported correctly, I usually open a3.5 session as a reader, and then I rebuild my models in V4, as many things have changed, I learn more "how to" like that. But often its usefull to open first an old model to see where COMSOL stores old data to better know where to define the things when you seem to have several choices in V4. AS some are better than others Have fun Comsoling ivar

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Posted: 1 decade ago 18 giu 2010, 10:22 GMT-4
Hi Ivar,
Thanks a lot for your information.
I have one more question regarding the problem.

Is it possible to use self-defined material in version 4.0.
It's possible to do this in version 3.5 where you can modify the variable expressions in the equation system, can we do the same in version 4.0?
Since I can not find how to do it? Seems version 4.0 is not as flexible as version 3.5a?
Thanks.
Li
Hi Ivar, Thanks a lot for your information. I have one more question regarding the problem. Is it possible to use self-defined material in version 4.0. It's possible to do this in version 3.5 where you can modify the variable expressions in the equation system, can we do the same in version 4.0? Since I can not find how to do it? Seems version 4.0 is not as flexible as version 3.5a? Thanks. Li

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Posted: 1 decade ago 18 giu 2010, 10:22 GMT-4
Hi Ivar,
Thanks a lot for your information.
I have one more question regarding the problem.

Is it possible to use self-defined material in version 4.0.
It's possible to do this in version 3.5 where you can modify the variable expressions in the equation system, can we do the same in version 4.0?
Since I can not find how to do it? Seems version 4.0 is not as flexible as version 3.5a?
Thanks.
Li
Hi Ivar, Thanks a lot for your information. I have one more question regarding the problem. Is it possible to use self-defined material in version 4.0. It's possible to do this in version 3.5 where you can modify the variable expressions in the equation system, can we do the same in version 4.0? Since I can not find how to do it? Seems version 4.0 is not as flexible as version 3.5a? Thanks. Li

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 18 giu 2010, 16:03 GMT-4
Hi

I would ay V4 is MORE flexible than 3.5, but I agree not everything is fully implemented, yet. From my understanding there are two ways:

you can add a material (from the library or set it up by your own from scratch) and then attach subdomain/volumes to this material.
Or you define material properties in the physics, by changing the tab "from material" to "user defined" and you get a new field to add the material properties.

Here, as before, you can use values, constants=Prameters or complex funtions

For me there is no difference in functionality, but some differences in methodology, but I have very rapidly adopted V4, and find it superiour to the previous one. Still as most X.0 releases with several improvements to be added, but they are coming, you can see that from the patches, and I have heard that the 4.0a should be soon made up.

have fun Comsoling
Ivar
Hi I would ay V4 is MORE flexible than 3.5, but I agree not everything is fully implemented, yet. From my understanding there are two ways: you can add a material (from the library or set it up by your own from scratch) and then attach subdomain/volumes to this material. Or you define material properties in the physics, by changing the tab "from material" to "user defined" and you get a new field to add the material properties. Here, as before, you can use values, constants=Prameters or complex funtions For me there is no difference in functionality, but some differences in methodology, but I have very rapidly adopted V4, and find it superiour to the previous one. Still as most X.0 releases with several improvements to be added, but they are coming, you can see that from the patches, and I have heard that the 4.0a should be soon made up. have fun Comsoling Ivar

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Posted: 1 decade ago 23 giu 2010, 05:56 GMT-4
Hi Ivar,

Not sure if I understood you correctly or not.

What I meant was to use a self-defined material.
For example, I want to use Ogden model, but there is no default material to be selected, thus I need to
define the strain energy function.

In v3.5 a, this can be done by
1. define global expressions from "Options - Expressions - Global Expressions",
2. Modify the formula from "Physics - Equantion system - Subdomain settings" where we can see how a material is implemented in Comsol.

But I can not see where can we find this in version 4.0? Or you've already answered my question but I didn't understand?
Thanks a lot for your help.
BR,
Li
Hi Ivar, Not sure if I understood you correctly or not. What I meant was to use a self-defined material. For example, I want to use Ogden model, but there is no default material to be selected, thus I need to define the strain energy function. In v3.5 a, this can be done by 1. define global expressions from "Options - Expressions - Global Expressions", 2. Modify the formula from "Physics - Equantion system - Subdomain settings" where we can see how a material is implemented in Comsol. But I can not see where can we find this in version 4.0? Or you've already answered my question but I didn't understand? Thanks a lot for your help. BR, Li

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