Week 4
Aim: To eliminate geometrical errors and mesh with the given element Quality criteria
CAD model: Bottle cap (Plastic component having variable thicknes)
Model Link:https://drive.google.com/file/d/1KAO5Ux26UCXll8_-f3aEk81hqIin-skh/view?usp=sharing
| S.No | Quality Criteria | Value |
| 1 | Target/Average length | 1 |
| 2 | Minimum Length | 0.5 |
| 3 | Maximum Length | 3 |
| 4 | Aspect | 3 |
| 5 | Warpage | 15 |
| 6 | Skewness | 45 |
| 7 | Jacobian | 0.7 |
| 8 | Minimum Quad Angle | 45 |
| 9 | Maximum Quad Angle | 135 |
| 10 | Minimum Tria Angle | 30 |
| 11 | Maximum Tria Angle | 120 |
| 12 | Tria Percentage | 15 |
Steps followed:
- Check and eliminate geometry errors.
- Mid surface extraction and setiing PID's.
- Generate mesh with-in quality criteria.
Procedure:
- The given CAD is in IGS format and is in readable format for ANSA
- After opening the file in ANSA, a topology is performed and is checked for any geometrical errors
- Most of the errors can be fixed by autofix option while some of the errors needs to be worked manually till clean geometry is achieved
- This is a plastic component and thickness varies at most of the features add so mid plane is extracted part by part and corresponding thickness is assigned at PID
- In Topo module, the middle, offset, intersect, new and extend options are widely used in extracting the mid surface/skin. These options are present under faces section
- Once the mid plane is extracted, the hot points around the perimeter and macros are refined to 1mm under Mesh module>Perimeter>Length
- Quality criteria values are assigned under quality criteria tab and also in mesh parameters tab
- Mesh is generated using best mesh option and using hidden mode in drawing styles, the elements or grids which are failing the quality are observed
- These can be rectified using reconstruct option
- Trias need to be maintained at least possible numbers as they are stiffening elements and leads to less accuracy in finite element analysis
- In order to avoid trias, split and swap options are used
Worked Model Link: https://drive.google.com/file/d/13H4Hlm-m2nx2yxxZ_1MmUlZIBxX3qXkF/view?usp=sharing
Conclusion: Geometry has been cleaned. Midsurface is extracted manually. PID for features are set with proper thickness. The component is meshed under specified quality criteria.