Week 5

Aim: To remove geometric errors and perform volume mesh using tetra elements with the given quality criteria.

Procedure:

Import the file using the shortcut key as it is easy to import he IGS format file using the shortcut key.Then perform the necessary fine tunnings.Do topo operation on the whole geometry to join nearby edges.

Run a geometry check on the whole geometry by choosing from the tools menu. This will show us all the geometry errors that need to be cleared before meshing.

Clear the errors found in the geometric check window.The errors can be fixed by two types auto and manually.Auto can fix a certain amount of erros if not fixed by the software then manually the error has to be fixed.

Now the geometric errors are fixed we move on to the meshing part, tetra volume meshing has to be done on this part so first we select the curved parts of the solid and perform the ortho tria meshing and flat surfaces can be meshed with normal tria. We use this because the ortho tria capture the curved parts accurately and flats can be meshed normal tria so that we don't put more stress on the software using the ortho trias on the flats.Before you perform these tasks we have to add the quality criteria i.e Trageted length should be 1mm and then in the shell drop down add the min. and max. length criteria and move to the solid drop down and add the collapse criteria after this add the given values to the criterias. Then mesh the geometry with these ortho trias and the flats with nrmal trias.

The images below show the ortho tria meshed parts

This image shows some of the edges meshed with ortho-trias.

This image shows all the parts that are meshed with the ortho-tria method.

This image show the parts that are normal tria meshed.

After this meshing of the geometry we have to now volume mesh it.To do that we have to define the volume of the geometry and then mesh it.

When you you define the volume you get a similar window apperaing as shown volume mesh window

After defining volumes we can now perform the tetra meshing on the geometry.This can be done by choosing the volumes seperately by right-clicking on the volume or by the whole geometry at once.there are different types of unstructured meshing method the method used here is the tetra-rapid method.tetra-FEM can also be used here.

Once you complete the volume meshing you get as similar result as shown in the images below

Results:

1. Performed geometric checks
2. Performed ortho-tria and tria meshing
3. Defined volume of the geometry
4. Volume meshing is done

Learning outcome:

• Ortho-tria meshing and tria meshing
• volume defination
• Volume tetra meshing