Some cells have negative volume error

[Narendra Nanal]

Hello All,

I am trying to read a mesh in dealii using abaqus input file. But I am getting following error-
    While sorting the cells that will be passed for creating a Triangulation object, deal.II found that some but not all cells have a negative volume. (If all cells had a negative volume, they would simply all have been inverted.) This usually happens in hand-generated meshes if one accidentally uses an incorrect convention for ordering the vertices in one or more cells; in that case, you may want to double check that you specified the vertex indices in their correct order. If you are reading a mesh that was created by a mesh generator, then this exception indicates that some of the cells created are so badly distorted that their volume becomes negative; this commonly occurs at complex geometric features, and you may see if the problem can be fixed by playing with the parameters that control mesh properties in your mesh generator, such as the number of cells, the mesh density, etc.
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When the input file is imported in abaqus it is working fine. Please see attached pictures.I am not sure if something is wrong with the mesh. Kindly guide me on how to resolve this error. Thanks in advance.

Regards,
Narendra Nanal

[Bruno Turcksin]

Narendra,

On Tuesday, December 5, 2017 at 11:27:15 AM UTC-5, Narendra Nanal wrote:

When the input file is imported in abaqus it is working fine. Please see attached pictures.I am not sure if something is wrong with the mesh. Kindly guide me on how to resolve this error. Thanks in advance.

You need to simplify the mesh as much as possible, i.e, decrease the number of cells, to understand what is going. Right now, there are way too many cells to find out which one is wrong.

Best,

Bruno

[Narendra Nanal]

Thank you so much Bruno

On Tuesday, December 5, 2017 at 11:27:15 AM UTC-5, Narendra Nanal wrote: