Hi,
I've been simulating the thermal distribution and tensions on a 3D tungsten block with a water pipe inside and a Cu interlayer, subject to a heat pulse on the top surface. Everything is consistent with the heat equation solver but the tensions results depend on grid and are non-physical.
I have prepared two meshes, one with Gmsh (frontal (2D) + delaunay (3D)) [1/4 of the geometry] and another with ElmerGrid [1/2 of the geometry] and computed the results on almost identical problems. I attach the images obtained on the von Mises with and without the grid overlay.
The results should be similar but they depend on grid and on the point of the grid.
I am probably doing something wrong and any comment is appreciated.
Grid or computation problem with linear elasticity module
Grid or computation problem with linear elasticity module
- Attachments
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- ElmerGrid result and grid overlay.
- vonMises_Egrid_b.png (87.7 KiB) Viewed 2063 times
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- Gmsh result with grid overlay.
- vonMises_gmsh_b.png (253.47 KiB) Viewed 2063 times
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- result with Gmsh grid.
- vonMises_gmsh.png (95.77 KiB) Viewed 2063 times
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Re: Grid or computation problem with linear elasticity modul
Hi
Are you using linear elements? Elasticity equation suffers from locking and particularly for stresses that are behind the derivative the results may be quite poor. Using quadratic elements might give nicer stresses. Just try with "Element = p:2" if you don't care to remesh.
-Peter
Are you using linear elements? Elasticity equation suffers from locking and particularly for stresses that are behind the derivative the results may be quite poor. Using quadratic elements might give nicer stresses. Just try with "Element = p:2" if you don't care to remesh.
-Peter
Re: Grid or computation problem with linear elasticity module
Hi Peter
Thank you for your suggestions.
I am still making tests with the quadratic elements and the results improve but not enough. The best strategy seems to be to increase the definition of the grid. I will post my final results when finish.
Nuno
Thank you for your suggestions.
I am still making tests with the quadratic elements and the results improve but not enough. The best strategy seems to be to increase the definition of the grid. I will post my final results when finish.
Nuno