#1 2008-06-17 13:14:31

mtg450

Member

Registered: 2008-06-17

Posts: 7

How to apply torque moments correctly?

Hello,

I started with a simple beam problem (one end fixed) and I want to apply a torque moment on the other end face.

I understood that the only(?) way to apply torques is with FORCE_NODALE, so I grouped the nodes on the face.

When calculating with a torque, I get the following error message:

                                                Le DDL MY est interdit pour le noeud N5

N5 is one of the corner nodes of the face with the moment.

When I change the load to a force f.e. parallel to the face I get a solution.

Where is my mistake?

best regards

André

YVES_MEZERETTE

Member

From: FRAISPERTUIS//88700 JEANMENIL

Registered: 2008-01-15

Posts: 218

Re: How to apply torque moments correctly?

Bonjour

Can you said to me how is your meshing .

Do you use a beam finite element POU_DT or other

Do you use an other mean of meshing plates or 3D finite element

Bye // Au revoir

YVES MEZERETTE

mtg450

Member

Registered: 2008-06-17

Posts: 7

Re: How to apply torque moments correctly?

Hallo,

Thanks for your quick reply.

I did the meshing with Salome, using hexahedron or tetrahedron makes no difference in the result.

YVES_MEZERETTE

Member

From: FRAISPERTUIS//88700 JEANMENIL

Registered: 2008-01-15

Posts: 218

Re: How to apply torque moments correctly?

Hallo,

Thanks for your quick reply.

I did the meshing with Salome, using hexahedron or tetrahedron makes no difference in the result.

Sorry

I want to know if our meshing is only on a line or if it is a plate because you said "I grouped the nodes on the face."

What face ? because it is a line when your meshing is a beam

Please , can you joint your meshing

YVES

Last edited by YVES_MEZERETTE (2008-06-17 14:09:52)

mtg450

Member

Registered: 2008-06-17

Posts: 7

Re: How to apply torque moments correctly?

Hello,

My model is a rectangular bar f.e. 20mm x20mm x100mm .
One of the 20x20 faces is fixed the other one is used to apply the load.

It is a "real" 3D-objects to try the first steps with Code Aster.

André

Francisc Boloni

Member

Registered: 2009-03-19

Posts: 21

Re: How to apply torque moments correctly?

I'm trying to model the same problem.

But it seems not obvious how to apply the torque. Any ideas ? (The mesh is composed of 3D elements)

Thanks !

keeswouters

Member

From: kuringen

Registered: 2007-12-01

Posts: 144

Website

Re: How to apply torque moments correctly?

Hoi

3D elements donot support moments in C-Aster, so you need to apply the torque by e.g. two forces in opposite direction, values of course depending on the distance between both forces. There are many possibilities for applying the torque: varying distances, the amount of forces. But the different solutions will only have local effects on the stresses and displacements at the tip of the 'beam'. And unless you are really interested in the behaviour at the end of the beam, it does not really matter what you choose.

** kind regards - kees

Last edited by keeswouters (2009-06-18 22:24:29)

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kind regards - kees
--
I a parallel univers the laws of mechanics may be different.

Thomas DE SOZA

Guru

From: EDF

Registered: 2007-11-23

Posts: 3,066

Re: How to apply torque moments correctly?

Have a look at http://www.code-aster.org/forum2/viewto … 668#p14668

TdS

miib

Member

Registered: 2021-03-23

Posts: 166

Re: How to apply torque moments correctly?

Hoi

3D elements donot support moments in C-Aster, so you need to apply the torque by e.g. two forces in opposite direction, values of course depending on the distance between both forces. There are many possibilities for applying the torque: varying distances, the amount of forces. But the different solutions will only have local effects on the stresses and displacements at the tip of the 'beam'. And unless you are really interested in the behaviour at the end of the beam, it does not really matter what you choose.

** kind regards - kees

confirm :-)

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I ever used code_aster for study.
“Non è bene cercare di fermare il progresso della conoscenza. L'ignoranza non è mai meglio della conoscenza.” Enrico Fermi.

miib

Member

Registered: 2021-03-23

Posts: 166

Re: How to apply torque moments correctly?

webthesis.biblio.polito.it/9286/1/tesi.pdf

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Attachments:
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I ever used code_aster for study.
“Non è bene cercare di fermare il progresso della conoscenza. L'ignoranza non è mai meglio della conoscenza.” Enrico Fermi.