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January 12, 2012, 14:02 |
stuck element vs prism layer
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#1 |
Member
hadrien calmet
Join Date: Nov 2011
Posts: 34
Rep Power: 15 |
Hello Every body
I would like to mesh a boat with appendices. I would like a fine mesh with good precision and small elements in the front and the tail of the boat and in the appendices, plus the prism layers around the boat and the apendices with different heigths. I use the following strategy: -first the "surface mesh" is done with curvature,proximity based refinement, all triangles, octree volume mesh. I delete all 3d elements and I run a Laplace smoothing -second I run a Delaunay volume mesh with the existing surface mesh, I perform some smoothing with quality criterion -third I create the prism layers all around the boat and appendices, with "fix marching" toggle on and to finish I perform some smoothing, freezing prisms and some with all types of elements, always with quality criterion. I obtain 25 M of elements , 5M of nodes and the quality is not good. Of course the prisms decrease the quality, but the worse is the prism generation produces some elements which occupy the same volume and stuck elements. I saw some post here about this problem, so I activated in advanced prism parameters "Prism v10.0" but it doesn't work "Do checks" and "Do not allow sticking" but it doesn't work I have always stuck elements. I tried also without "fix marching direction" but it doesn't work I tried also without laplace smoothing but it doesn't work -------------------------------------------------------- Other problem is the junction between the boat and the apendice with the prism layers. I have attached a picture Can anyone help or give me some advice ??? thank you |
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January 13, 2012, 10:37 |
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#2 |
Senior Member
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,663
Blog Entries: 1
Rep Power: 47 |
You just need to reduce the transition. The keel is much finer than the hull so it is having trouble with the transition. Refine the mesh on the keel for some distance out from the hull and it will be able to handle the corner... Then have it transition to the larger mesh size over some distance so the prism height transition will be smooth...
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January 13, 2012, 12:58 |
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#3 |
Member
hadrien calmet
Join Date: Nov 2011
Posts: 34
Rep Power: 15 |
Thank a lot Simon !
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January 18, 2012, 10:38 |
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#4 |
Member
hadrien calmet
Join Date: Nov 2011
Posts: 34
Rep Power: 15 |
I reach to obtain 0 stuck elements !!!!!
- help the transition like Simon said - don't forget to toogle on "do check", "not allowed ..." -some layers(3) without height info -split the 3 layers in 10 layers with "fix ratio" -redistribute 10 layers with fix ratio if this can help someone ! |
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January 23, 2012, 14:00 |
problem geometry
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#5 |
Member
hadrien calmet
Join Date: Nov 2011
Posts: 34
Rep Power: 15 |
Hello
now, to no waste too much elements, I want to cut the hull to put prisms only on down part and decrease the size element on the top part. So I produce curves on the intersection of one plan and the hull, I segment the surface hull with the plan (I tried to segment with the curves but it don't work !) , see fig 4.jpg. I mesh the hull and I obtain this surface mesh (see figure 1,2,3 jpg). I use the curvature on the down part and not on the top part (see 2.jpg). Some one can explain me or help me to remove these horrible refinement in the intersection (see 1,3 jpg) and improve the edge (see 2.jpg) |
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January 23, 2012, 14:02 |
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#6 |
Member
hadrien calmet
Join Date: Nov 2011
Posts: 34
Rep Power: 15 |
ooops i forgot the pictures
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