Assignment 1

Skill-lync hyper works assignment 1

Objective: The objective of this challenge is to import the given geometries into the hyper works workspace, check them for errors like free edges and fix any that arise, create a representative mid-surface for the geometries and repair any errors that arise, remove any unnecessary geometric features from those mid-surfaces, and create an FE mesh for these mid-surfaces that meet the specified quality criteria.

Case setup: The first component is a sheet metal unit with a uniform thickness of 0.91 mm. A screenshot of the component is shown below.

Figure 1: First component (Part-1)

The second component shown below has a uniform thickness of 2 mm.

Figure 2: Second component (Part-2)

The third component has a uniform thickness of 1.8 mm.

Figure 3: Third components (Part-3)

Procedure: The 3 components are worked on separately. The operations conducted on each component are listed below.

1. The component is imported into the Hyper-works workspace.
2. The geometry color mode is then set to mixed so that free edges are highlighted in red.
3. The geometry>quick edit>toggle edge option is used to combine two free edges that are really close to each other. One such instance is shown below.

Figure 4: Before toggle edge

Figure 5: After toggle edge

4. An alternative method uses the replace point option in the quick edit tab to merge the end points of these free edges together, as illustrated below.

Figure 6: Missing surface

Figure 7: Replacing point at one end

Figure 8: Before replacing point at other end

Figure 9: Final stitched edge

5. Missing surfaces are recreated using the filler surface option in the quick edit tab, as shown below.

Figure 10: Second missing surface

Figure 11: Filler surface

6. Unnecessary extra faces are deleted using the delete option, as shown below.

Figure 12: Extra face

Figure 13: After removing extra face

7. Overhanging surfaces are trimmed by the geometry>surface edit>trim with lines options, as shown below. The overhanging surface section is then deleted.

Figure 14: Overhanging face

Figure 15: Trimmed face

8. The mid-surface for the component is generated by the geometry>mid-surface option. The mid-surface generated is shown below.

Figure 16: Resultant mid-surface

9. Hole diameters are measured using the geometry>distance>three node option.
10. If hole diameter is less than 5 mm, the hole is removed by the geometry>surface edit>un-trim option, as shown below.

Figure 17: Holes before un-trim

Figure 18: Removed holes

11. Defeaturing of the mid-surface is performed by removing connecting lines via the toggle edge option, as shown below.

Figure 19: Before defeaturing

Figure 20: After defeaturing

12. Corners are refined to meet quality criteria by the replace points option, as illustrated below.

Figure 21: Corner before defeaturing

Figure 22: Corner after defeaturing

13. The mid-surface is meshed section-by-section using the 2D>auto-mesh option, with a target length as illustrated below.

Figure 23: Surface before meshing

Figure 24: Meshed surface

14. In edges where elements are not connected through their nodes, they are connected by hitting Shift+F3, and connecting discontinuous nodes, as shown below.

Figure 25: Misaligned nodes

Figure 26: Aligned nodes

15. The quality of the overall mesh is checked by the 2D>quality index option, to see if elements fit within the quality criteria of minimum element length (3.5 mm) and maximum element length (7 mm).

Figure 27: Quality of mesh

16. The mesh is then improved by element optimize within the element cleanup tools, as well as the 2D>rebuild mesh option, as shown below.

Figure 28: Fixed mesh

17. The thickness property of the component is set to be 0.91 mm.
18. The entire process is repeated for the two other components.

Additional images:

Figure 29: Final mesh for first component

Figure 30: Mid-surface for second component

Figure 31: Final mesh for second component

Figure 32: Mid-surface for third component

Figure 33: Final mesh for third component

Result: The three components had their mid-surfaces generated and meshed appropriately.

• The first component (Part-1) was easiest to operate on, owing to its rectangular profile. It had only one hole that needed to be modelled. This resulted in a mesh made almost entirely of quad elements.
• The mid-surface of the second component (Part-2) could not be properly generated. The greatest challenge in this assignment came from fixing the mid-surface generated. The repair involved recreating a couple of fillets between two surfaces. The symmetry of this component allowed for reflecting some sections of the mesh, thus cutting down on overall work.
• The third component (Part-3) had the most geometrically complex mid-surface that required considerable defeaturing. Quality criteria could not be met adequately at base holes, since they were large enough to need modelling and they were too close to a critical feature (a rib).

Conclusion: The assignment has been an exercise in the use of hyper-mesh for generating 2D FE mesh for given geometries.