Week 3 - 2D meshing for sheet metal

REPORT

Aim:-

To extract the mid-surface of the hood model and mesh it

Procedure:-

1. The model is imported to ansa
2. Before beginning, we follow some steps
3. The first step is to perform cons resolution
4. Then it is followed by the cons checkup
5. We proceed with the single cons, which is done by hiding the single and double cons.
6. Then we have to check for the orientation.
7. After that we can proceed to the geometry checkup which is done by check manager >geometry >check single cons and other parameters >execute
8. If there are errors, they are rectified there only by right click on the error and fix.
9. Since it is a sheet metal component, therefore the thickness is constant, so we begin by taking the offset of the component
10. To carry out the offset, we begin by taking the thickness and dividing it by half and selecting the property as “auto-create” so that a property is created for the offset solely.
11. Now, the offset surface is known as the mid-surface.
12. After the mid surface is extracted, meshing has to be performed and now we start it.
13. To begin with 2D meshing, the first step is to go to Perimeter> Length> enter target element length which is 5mm
14. Then we set up the Mesh parameter which as been given
15. Then we set up the quality criteria which has been given
16. Then we make the necessary cuts and modifications under the mesh module >macros
17. While making the cuts, care has been taken to ensure that the feature lines are not removed as they are very important. They are usually on fillets etc.
18. We make these cuts in order to ensure a proper mesh flow
19. Since many components are symmetrical, one-half of the component is deleted and then reflected after meshing. With this technique, a huge amount of time is saved.
20. Then we begin with meshing under - mesh module>mesh generation>best
21. If the mesh generated is not proper, we reconstruct is using the - shell mesh>reconstruct
22. We can also make the necessary changes in elements count and type.
23. This is done by – Perimeter >Num+/- >values
24. We can also split the elements in order to control the mesh flow
25. 2D Meshing is created and it is made sure that there are fewer tria elements as they are stiffer than quads.
26. Thickness is assigned after meshing the model.
27. Similar steps are incorporated for each component.

Images:-

Component Image - Latch Mid-surface - Latch

Meshed Surface - Latch Component Image- Hinge

Mid-surface Hinge Meshed Surface

Component Image - Outer Panel Mid-surface outer panel

Meshed Outer Panel Component Image - Inner Panel

Meshed Inner Panel

Learning Outcomes: -

• Learnt about topology clean-ups
• Learnt about offset and extraction of mid-surface
• Learnt about the cons resolution which is very crucial
• Learnt about the proper ways of splitting and optimization of elements in order to get good mesh flow
• Learnt about the transform tool > Symmetry

Conclusion :-

It can be concluded that each and every step is very crucial in order to get a proper mesh and mesh flow.