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Mesh generation in Comsol 4.3b for Stacked

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Hi Guys.
I have 4 stacked layers starting from very thick (50 um) to very thin (30 nm) thicknesses. I have problem with mesh generation. Tried everything but could not mesh the geometry. The thinnest layer cannot be meshed. Could anyone help me out here?!
Thank you.
Mohsen


6 Replies Last Post 27 févr. 2015, 05:08 UTC−5

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Posted: 1 decade ago 6 mai 2014, 05:38 UTC−4
I am using version 4.4, so you cannot open my file, but I tell you what to do.
1. Make a free triangular mesh on the top face of the stack.
2. Sweep that mesh across the whole stack.
3. You can then refine the mesh in vertical direction with the distribution property, i.e. defining to each layer how many elements you wish.

I made a mesh with 5 layers to the three upper layers and 25 layers to the lowest one. Attached a picture. You cannot see the thinnest layer in this magnification, but trust me, there are 5 layers also in the uppermost one.

"Complete mesh consists of 31280 domain elements, 6790 boundary elements, and 520 edge elements."

Wish this helps
Lasse
I am using version 4.4, so you cannot open my file, but I tell you what to do. 1. Make a free triangular mesh on the top face of the stack. 2. Sweep that mesh across the whole stack. 3. You can then refine the mesh in vertical direction with the distribution property, i.e. defining to each layer how many elements you wish. I made a mesh with 5 layers to the three upper layers and 25 layers to the lowest one. Attached a picture. You cannot see the thinnest layer in this magnification, but trust me, there are 5 layers also in the uppermost one. "Complete mesh consists of 31280 domain elements, 6790 boundary elements, and 520 edge elements." Wish this helps Lasse


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Posted: 1 decade ago 6 mai 2014, 06:16 UTC−4
Lasse,
Thank you for the suggestion. I have encountered another problem while meshing the topmost layer, which is the thinnest one. Consider we just have a block of 3000*3000*0.03 um. If I mesh it with Tetrahedral it gives me an error which indicates that the shortest edge is smaller than the minimum mesh size. If I wanna refine it with Size, and put for example 0.025 um for the minimum edge size, then even with supercomputer it doesn't process the meshing beyond 1% !!! Would you advise me how to mesh this thin layer?
Thank you.
Mohsen
Lasse, Thank you for the suggestion. I have encountered another problem while meshing the topmost layer, which is the thinnest one. Consider we just have a block of 3000*3000*0.03 um. If I mesh it with Tetrahedral it gives me an error which indicates that the shortest edge is smaller than the minimum mesh size. If I wanna refine it with Size, and put for example 0.025 um for the minimum edge size, then even with supercomputer it doesn't process the meshing beyond 1% !!! Would you advise me how to mesh this thin layer? Thank you. Mohsen

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Posted: 1 decade ago 6 mai 2014, 07:50 UTC−4
No tetrahedrons but a triangular mesh on the top. It is found under "More operations". You mesh first only the uppermost face which is then swept across the entite stack. You must learn the swept mesh, it is the only way of meshing thin layers. If you had Comsol 4.4 I could send you the file.
No tetrahedrons but a triangular mesh on the top. It is found under "More operations". You mesh first only the uppermost face which is then swept across the entite stack. You must learn the swept mesh, it is the only way of meshing thin layers. If you had Comsol 4.4 I could send you the file.

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Posted: 1 decade ago 6 mai 2014, 08:00 UTC−4
YES! It works!! Thanks a lot Lasse.
YES! It works!! Thanks a lot Lasse.

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Posted: 10 years ago 27 févr. 2015, 04:37 UTC−5
Hi
please help me in meshing my model.some time the program makes new mesh and fail to mesh.
I have 20 small cylinders in 1 mm .and model Ellipse (a=40,b=10).
I tried many time but failed.
thank you
Hi please help me in meshing my model.some time the program makes new mesh and fail to mesh. I have 20 small cylinders in 1 mm .and model Ellipse (a=40,b=10). I tried many time but failed. thank you

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Posted: 10 years ago 27 févr. 2015, 05:08 UTC−5
Your cylinder height is 1 mm? Cylinder cross-section is elliptic? 20 cylinders in a stack?

Mesh first the top (or bottom) surface with triangles, then sweep across the cylinder and add distribution to the swept mesh.

I need to see the geometry to reply more accurately.

br
Lasse

Your cylinder height is 1 mm? Cylinder cross-section is elliptic? 20 cylinders in a stack? Mesh first the top (or bottom) surface with triangles, then sweep across the cylinder and add distribution to the swept mesh. I need to see the geometry to reply more accurately. br Lasse

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