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Contributor
sriramsheval
Posts: 24
Registered: ‎10-21-2013

Mesh quality - Poor

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11-04-2013 06:21 PM

Hi,

 

I'm working on simulation of a small assembly, I heard that good meshing quality results in accurate results.

 

When I try to mesh my model, initially surface mesh looks good, as shown in picture below1.PNG

 

After this, I gave the boundary conditions, and proceed for the analysis. When I was evaluating the results, I saw the solid mesh through a cut sectional view as below 2.PNG

 

I tried both fine and cores mesh sizes, but solid mesh quality is as shown here, will the results I achieve would be accurate with such a irregular mesh?

 

I need any one to help me know, that is mesh quality (not mesh size, but the element arrangements) affect the result?

 

Any options to prevent such irregular solid meshing.3.PNG

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Employee
zhuangs
Posts: 262
Registered: ‎10-04-2010

Re: Mesh quality - Poor

11-05-2013 01:40 PM in reply to: sriramsheval

Only use "Tetrahedron" element can help quite a lot.

 

-Shoubing

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Contributor
DonaldR.Culp7481
Posts: 24
Registered: ‎05-18-2010

Re: Mesh quality - Poor

03-16-2014 05:21 PM in reply to: sriramsheval

When you create a sectional view through the mesh, it is very difficult to determine the equality of the mesh because the elements may not be oriented parallel to the sectional plane. (Such orientation may be impossible for elements that are not 8-noded bricks .)

 

The best approach that I have found is:

1. In your solid model (probably before transferring to FEMPRO), split the model (or selected parts) along planes where you would like to have a nice mesh. For example, divide the cyan rod into two identical semicircular rods by a vertical cutting plane (i.e., in the YZ plane). One of the resulting parts would the same as in your second figure (but without the mesh). The other would be the mirror image of that part.

2. For each part that was split, apply identical material properties to the resulting split parts.

3. Mesh the model as usual. Now you will have a nice surface mesh on each of the two mating faces of the split parts. You can easily view this mesh by hiding one of the split parts. This also simplifies adding refinement points which would seem to be needed here.

4. The resulting solid mesh should be much better.

 

The same should be done for the mating red part.

 

Note: to achieve the desired mesh quality you may need to apply a secondary split along an XY plane centered on the axis of the red part. This would yield four identical cyan parts and four identical red parts parts.

 

Don C.

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