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How to mesh plate with elliptical surface crack in comsol 4.1??

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Hi,

I am trying to mesh plate with semi ellipsoid surface crack with tetrahedral element.Results i am getting, but some points shows the inverted mesh.how to deattach those point in comsol?/

Pls reply..


Deepak

3 Replies Last Post 7 mai 2011, 06:40 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 5 mai 2011, 09:52 UTC−4
Hi

COMSOL normally changes the "2nd order" shape functions to linear where the the "inverted mesh" is identified. This is normally a warning, only. So basically COMSOL is looking after it. I'm not sure you need to worry more about it, apartthat you might ahve some "hot spots" or singularities building up hat are numeric, and not phsics

--
Good luck
Ivar
Hi COMSOL normally changes the "2nd order" shape functions to linear where the the "inverted mesh" is identified. This is normally a warning, only. So basically COMSOL is looking after it. I'm not sure you need to worry more about it, apartthat you might ahve some "hot spots" or singularities building up hat are numeric, and not phsics -- Good luck Ivar

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Posted: 1 decade ago 7 mai 2011, 02:24 UTC−4
How to get rid of singularity & hot spot??
How to get rid of singularity & hot spot??

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

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Posted: 1 decade ago 7 mai 2011, 06:40 UTC−4
Hi

by using smooth (BC's "smoothly" applying loads on the boundaries or domains and not on lower order elements (edges or points in 3D). Avoid sharp edgs in the geometry^, the vertexs of a cube can inherite its properties from 3 faces / boundaries, hence it will take a "mean value" depending on the values of the 3+ nabouring faces, and edges, furthermore an external boundary does not (mostly) have any external load that balaces the domain laods, so stress, orelectric field or ... will build up.

i.e.e ACDC ES: where do you expect the highest fields ? close to sharp corners (that is physics, but the meshing and element discretisation tends also to worsen the effects, sometimes in an unphysical way, but not always ;)

--
Good luck
Ivar
Hi by using smooth (BC's "smoothly" applying loads on the boundaries or domains and not on lower order elements (edges or points in 3D). Avoid sharp edgs in the geometry^, the vertexs of a cube can inherite its properties from 3 faces / boundaries, hence it will take a "mean value" depending on the values of the 3+ nabouring faces, and edges, furthermore an external boundary does not (mostly) have any external load that balaces the domain laods, so stress, orelectric field or ... will build up. i.e.e ACDC ES: where do you expect the highest fields ? close to sharp corners (that is physics, but the meshing and element discretisation tends also to worsen the effects, sometimes in an unphysical way, but not always ;) -- Good luck Ivar

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