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Deforming an edge in Deformed Geometry Interface in 3D model.

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Hi All,

We are working on a comsol model with Solid Mechanics and Deformed Geometry interfaces.

In our 3D model, we are using Prescribed Normal Mesh Velocity and Prescribed Mesh Displacement to assign required deformation in the domain. In 3D models, these both interfaces are applicable to a particular face only and not on any edges.
Is it possible to apply, a prescribed mesh displacement along an edge (not on a face) in 3D, using weak constraint or Pointwise Constraint or in any other way.

Thanks in advance. Regards. A. P.


3 Replies Last Post 11.03.2020, 09:56 GMT-4
Henrik Sönnerlind COMSOL Employee

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Posted: 5 years ago 09.03.2020, 11:30 GMT-4

In most cases, that would not form a well-posed problem. The question here is: What condition is to be applied on the boundaries adjacent to that edge?

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Henrik Sönnerlind
COMSOL
In most cases, that would not form a well-posed problem. The question here is: What condition is to be applied on the boundaries adjacent to that edge?

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Posted: 5 years ago 11.03.2020, 05:40 GMT-4

Thanks for reply. If we assume that the problem is well posed, can you indicate which system-variables can be used to move an edge?

Thanks for reply. If we assume that the problem is well posed, can you indicate which system-variables can be used to move an edge?

Henrik Sönnerlind COMSOL Employee

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Posted: 5 years ago 11.03.2020, 09:56 GMT-4

In principle, it should be possible to put a pointwise (or weak) constraint on material.u, material.v, etc. (In the Dependent Variables node, you can see the names of the degrees of freedom for the mesh displacement).

Such a setting will, however, usually conflict with boundary conditions (explicit or implicit) on the adjacent boundaries. Unless you know exactly what is going on under the hood, chances are rather large that you will get unexpected results. In particular, a boundary without other boundary conditions is implicitly fixed.

Try it out on a small simple example if you still want to explore this path.

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Henrik Sönnerlind
COMSOL
In principle, it should be possible to put a pointwise (or weak) constraint on *material.u*, *material.v*, etc. (In the Dependent Variables node, you can see the names of the degrees of freedom for the mesh displacement). Such a setting will, however, usually conflict with boundary conditions (explicit or implicit) on the adjacent boundaries. Unless you know exactly what is going on under the hood, chances are rather large that you will get unexpected results. In particular, a boundary without other boundary conditions is implicitly fixed. Try it out on a small simple example if you still want to explore this path.

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