Geometry cleanup and 2D meshing as per given criteria

Objective: To clean the given geometries and apply 2D meshing as per required criteria for element length.

Steps Followed:

1. The .hm files containing the models were imported in hyperworks (Optistruct profile).
2. The model is made sure to have a closed volume for 'midsurface' option to use.
3. Toggle edge option from edge edit panel was used effectively to get rid of unnecessary free edges.As per asked in the problem, holes with diameter less than 5mm were ignored and using fill surface option (with toggle edge) taken care of.
4. The replace points option was used to get rid of unnecessary sharp corners and areas of the model to avoid bad quality elements.
5. Automoesh option in 2D panel was used to mesh the geometry with element size 5mm.
6. Element check option was edited as per required citeria for min. and max. element length and elements were checked accordingly.
7. Element cleanup option in 2D panel was used to edit the failing elements.
8. This editing usually disturbs the mesh flow and if possible should be avoided.The min. element criteria was deliberately ignored for the elements which are are necessarily small to capture the geometric features which are absolutely necessary for the analysis.Ex washer elements,elements capturing holes bigger than 5mm dia.,etc.
9. The min. element length criteria meant some fillets, curvatures, holes were ignored completely.The element project option was used extensively for this purpose.
10. After the mesh is edited to acceptable standards as per given criteria,a material entity named after the model is created in this case with MAT1 card.
11. A property entity is created with PSHELL card here, with the material entity and assigned to the elements.
12. The component Midsurface is then updated for this property, another way of assigning the material, and property to the created mesh.

Part-1: Clip repair

As seen in image above after editing the mesh to min. element length criteria the flow is disturbed with tria elements and crooked mesh.The smaller element near the hole are a necessity to properly capture the hole and adjecent geometry.

An image without the edits is as follows:

The 2D representation of the mesh:

Part2-practice:

Similar to 1st case the min. element length criteria can be crucial.Here is an image where only the necessary changes are done.

A strict followup of the criteria creates a crooked mesh as follows:

A 2D representation of the mesh:

Part 3 - Mounting bracket:

In this case as the geometry has a lot of narrow features, many of the necessary elements are failing against the min. length criteria.If followed,the elements don not capture the geometry rather cross the boundries completely hence the criteria is ignnored wherever possible.

A 2D representation of the mesh:

After the suggested changes to strictly meet the min. Element criteria, Element cleanup operations from 2D TAB as well as Node translation operations were used. Wherever necessary remeshing is done. The edited mesh is as follows:

Part-1:

https://drive.google.com/open?id=1fniQg4GH49PdGHPvvZt8fql0oHD42xSa

Part-2:

https://drive.google.com/open?id=1GD3CFP1BQ1HgtpPmrljGk2IyquWs0SkF

Part-3 :

Edited images with better flow and all quad elements:

Part 1:

Part 2:

Part 3:

Conclusion:

It can be concluded that the element quality criteria can be followed only whererver it improves the accurancy of the results and hence should depend on the type of analysis to be performed.

A link to folder containng all .hm models:

https://drive.google.com/open?id=1gtQOmxnFkBjqBIcEZjjzPunu4Scem-jM

edited file as per the changes suggested:

https://drive.google.com/open?id=1mnkkx0QHU5vESP4_hyTOALx5XNCbE3KI