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Surface traction in COMSOL 4.0

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Hi everyone!

I used to work with COMSOL 3.5 and recently updated to COMSOL 4.0 which has very different interface comparing to previous version. The problem that I faced with is I try to define torsional moment acting on cylinder. In 3.5 I could define moment as stress distribution over the boundary,e.g. Taz_smsld*y-Tay_smsld*z, where Taz_smsld and Tay_smsld denotes for surface traction in z direction (as far as I understand).
Now I try to apply the same principal in 4.0, but I really confuse with defining surface traction. Is there reserved name for it (as it was in 3.5 Taz_smsld, etc).

Thank you for your help!

Artem

7 Replies Last Post Jun 10, 2014, 6:47 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jan 13, 2011, 1:53 a.m. EST
Hi

first of all update to 4.1 and patch it to latest, 4.0 was an early version and has many small frustrating issues

read carefully the doc (4.1 is also much better than 4.0) as all names have changed, a little ;)
for the variables basically you replace the "_smsld" postfix by a prefix "solid." (à la Java or other programming)

Really consider it s a new approach, it takes afew days, but then you do not want to go back to 3.5 again ;)

--
Good luck
Ivar
Hi first of all update to 4.1 and patch it to latest, 4.0 was an early version and has many small frustrating issues read carefully the doc (4.1 is also much better than 4.0) as all names have changed, a little ;) for the variables basically you replace the "_smsld" postfix by a prefix "solid." (à la Java or other programming) Really consider it s a new approach, it takes afew days, but then you do not want to go back to 3.5 again ;) -- Good luck Ivar

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Posted: 1 decade ago Jan 13, 2011, 1:26 p.m. EST
Thank you, Ivar,

I like the new version, but as you mentioned it takes time to adjust to its new interface.
I'll install 4.1 later.

The question that I have its about the capability to solve turbulent flow in 4.1. Is it possible to solve flow over rotating structures (i.e. rotating blades, etc.)? Because I found good picture on COMSOL website with flow passing the fan. I asked supporting group and they said the 4.0 version are not able to perform such an analysis. What about 4.1?

Also, when I tried to solve time-depending turbulent flow passing 3-D structure, I always get an error in: "Couldn't get initial value". Because I didn't find any example in such application. The only thing is transient laminar flow or parametric turbulent flow. So does COMSOL solve time-dependent turbulent flow at all?

Best regards,

Artem
Thank you, Ivar, I like the new version, but as you mentioned it takes time to adjust to its new interface. I'll install 4.1 later. The question that I have its about the capability to solve turbulent flow in 4.1. Is it possible to solve flow over rotating structures (i.e. rotating blades, etc.)? Because I found good picture on COMSOL website with flow passing the fan. I asked supporting group and they said the 4.0 version are not able to perform such an analysis. What about 4.1? Also, when I tried to solve time-depending turbulent flow passing 3-D structure, I always get an error in: "Couldn't get initial value". Because I didn't find any example in such application. The only thing is transient laminar flow or parametric turbulent flow. So does COMSOL solve time-dependent turbulent flow at all? Best regards, Artem

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

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Posted: 1 decade ago Jan 13, 2011, 2:01 p.m. EST
Hi

I have done a few rotating flow to motion simulations so in 4.1 it starts to work, probably it will be better in 4.2 even but in 4.1 it's already possible

--
Good luck
Ivar
Hi I have done a few rotating flow to motion simulations so in 4.1 it starts to work, probably it will be better in 4.2 even but in 4.1 it's already possible -- Good luck Ivar

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Posted: 1 decade ago Jan 13, 2011, 2:09 p.m. EST
Good news =)

I'll test it tonight to get any results. Do they have any tutorials in such application?

Artem
Good news =) I'll test it tonight to get any results. Do they have any tutorials in such application? Artem

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

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Posted: 1 decade ago Jan 14, 2011, 6:54 a.m. EST
Hi

not I believe not yet. But ih v4.1 you can regularly upload new library models from inside COMSOL application, check your doc

--
Good luck
Ivar
Hi not I believe not yet. But ih v4.1 you can regularly upload new library models from inside COMSOL application, check your doc -- Good luck Ivar

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Posted: 1 decade ago Jun 10, 2014, 4:18 a.m. EDT
HI

I am having the same problem in version 4.3.

Taz_smsld and Tay_smsld in V3.5a denotes for surface traction

What will be the name in V4.3?

Regards,
H
HI I am having the same problem in version 4.3. Taz_smsld and Tay_smsld in V3.5a denotes for surface traction What will be the name in V4.3? Regards, H

Henrik Sönnerlind COMSOL Employee

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Posted: 1 decade ago Jun 10, 2014, 6:47 a.m. EDT

HI

I am having the same problem in version 4.3.

Taz_smsld and Tay_smsld in V3.5a denotes for surface traction

What will be the name in V4.3?

Regards,
H


In version 4, the name would be solid.Taz etc.

You will find the components in the results under Solid Mechanics -> Stress -> Traction

Regards,
Henrik
[QUOTE] HI I am having the same problem in version 4.3. Taz_smsld and Tay_smsld in V3.5a denotes for surface traction What will be the name in V4.3? Regards, H [/QUOTE] In version 4, the name would be solid.Taz etc. You will find the components in the results under Solid Mechanics -> Stress -> Traction Regards, Henrik

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