Assignment 1-2D Meshing Challenge

Objective:

• To clean the geometry.
• Extract midsurface.
• To mesh the midsurface.
• To assign proper thickness by creating a generic property.

Cad model image:

• Part 1

• Part 2

• Part 3

Procedure:

For Part 1,

• We have to understand the geometry and find errors and clear them.
• Like toggling free edges, fill the missing surfaces, delete the extra surfaces and trim and delete extra surfaces.

• Blue- Toggle free edges.
• Orange- delete extra surfaces
• Green- Missing surface
• Purple- Trim with planes or surfaces and remove extra surface.

• Extract the midsurface by using automidsurfacing.
• Used the offset only in automidsurface.

• Now we have to cleanup the midsurface to get a good mesh flow.

• Blue- Toggle these lines as the area is very small so the geometry would fail if we try to capture the geometry.
• Orange- remove the holes as they are less than 5mm diameter.
• Yellow- defeature the fillets.
• Green- Toggle these as we cannot defeature because it makes two points very close and cannot be meshed without failing the elements.

• If we defeature and mesh the elements fail for minimum element length.

• Toggle these lines.

• Thats why we cannot defeature this and instead we toggle it as it makes 2 points very close to each other and also far away that we cannot replace these points.
• Cleaned Geometry,

• Now we mesh the part.

• At this part we should replace the points as the points are very close and element will fail over there.
• After replacing, .
• These portion has to be captured this way, because the component is very small.

• In this model, there are two options, 1st to capture the entire geometry and let the elements fail or 2nd to focus on the quality.
• Last step is to assign property and thickness to the component.

For Part 2,

• All the operations are similar to part 1
• Extract midsurface by offset.
• For cleanup the top surface had two points very close so just replace those points.
• And being symmetrical component we can use options like reflect and position and connect the points by equivalance from edges.
• Here the bottom part has holes which cannot be captured without failing the element and all the small holes have the same size of 5mm.
• So it creates a confusion whether to keep the holes or not.
• I was advised to remove the holes so I removed it.
• The cleaned up geometry and mesh are like this,

• If we keep holes,

• But keeping holes leads to failure of elements,

• Final steps include passing the quality criteria and assigning thickness property.

For Part 3,

• Very much similar to part 2 in operations but the geometry was very complicated.
• Similar to part 2 being symmetrical component we can use options like reflect and position and connect the points by equivalance from edges.
• Here we toggled huge part of the fillet region and let the mesh decide for itself.

• Had to remesh and rebuild mesh and perform various quality improving criterias to protect the elements from failing.
• Here the reflect and position were used alot.
• Cleaned geometry,

• Lastly check quality and assign thickness property.

Result and final model:

After turning on 2d detailed element representation.

Part 1

Part 2

Part 3

Conclusion-

• Hence we learned how to clean geometry, extract midsurface, clean midsurface geometry and assign property with thickness.