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Quadratic tetrahedral elements

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Hello,

i am working on a project where i need to do a mesh with quadratic tetrahedral elements ( tet with 10 nodes), but i cannot find how to do this in comsol? Does anyone please have an idea how to do this?

Thank you in advance

4 Replies Last Post 2016年9月5日 GMT-4 04:30

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Posted: 8 years ago 2016年8月31日 GMT-4 03:26
Hi,

in Comsol this topic is treated different than in other FEM codes.

1. In the meshing step you create a tetrahedral mesh.

2. In the discretisation setting of the physics section you select Lagrange and quadratic.

Then this will be like a 10-node tetra in Ansys.

The discretisation is not visible by default and you must activate it in the model tree ("Show" button).
Also the quadratic Lagrange is default for many types of physics.

Regards

Jens
Hi, in Comsol this topic is treated different than in other FEM codes. 1. In the meshing step you create a tetrahedral mesh. 2. In the discretisation setting of the physics section you select Lagrange and quadratic. Then this will be like a 10-node tetra in Ansys. The discretisation is not visible by default and you must activate it in the model tree ("Show" button). Also the quadratic Lagrange is default for many types of physics. Regards Jens

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Posted: 8 years ago 2016年8月31日 GMT-4 04:02

Hi,

in Comsol this topic is treated different than in other FEM codes.

1. In the meshing step you create a tetrahedral mesh.

2. In the discretisation setting of the physics section you select Lagrange and quadratic.

Then this will be like a 10-node tetra in Ansys.

The discretisation is not visible by default and you must activate it in the model tree ("Show" button).
Also the quadratic Lagrange is default for many types of physics.

Regards

Jens



Thank you for your reply.. But what if i want to export the displacements DX DY DZ on the 10 nodes and the connectivity file to use them in other calculation... the connectivity file will include all the faces with just 3 or 4 faces ... i need a connectivity file for the 10 nodes + the displacements on these nodes... is it possible ?

thanks
[QUOTE] Hi, in Comsol this topic is treated different than in other FEM codes. 1. In the meshing step you create a tetrahedral mesh. 2. In the discretisation setting of the physics section you select Lagrange and quadratic. Then this will be like a 10-node tetra in Ansys. The discretisation is not visible by default and you must activate it in the model tree ("Show" button). Also the quadratic Lagrange is default for many types of physics. Regards Jens [/QUOTE] Thank you for your reply.. But what if i want to export the displacements DX DY DZ on the 10 nodes and the connectivity file to use them in other calculation... the connectivity file will include all the faces with just 3 or 4 faces ... i need a connectivity file for the 10 nodes + the displacements on these nodes... is it possible ? thanks

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Posted: 8 years ago 2016年9月5日 GMT-4 04:23
Have you tried the Data Export in the Results section? Under "Advanced"
there is a combe box labeled "Evaluate in" where you can select "Lagrange Points"

Regards

Jens
Have you tried the Data Export in the Results section? Under "Advanced" there is a combe box labeled "Evaluate in" where you can select "Lagrange Points" Regards Jens

Lars Gregersen COMSOL Employee

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Posted: 8 years ago 2016年9月5日 GMT-4 04:30
Hi

If you have access to LiveLink for Matlab you can use mpheval to extract data for each node (use refine=2 for second order lagrange elements).

Using mphmeshstats and mphxmeshinfo you can get all the information you need about mesh data and elements including numbering and connectivity.

--
Lars Gregersen
Comsol Denmark
Hi If you have access to LiveLink for Matlab you can use mpheval to extract data for each node (use refine=2 for second order lagrange elements). Using mphmeshstats and mphxmeshinfo you can get all the information you need about mesh data and elements including numbering and connectivity. -- Lars Gregersen Comsol Denmark

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