Week 12:Project-1-Meshing of Door Inner Panel Challenge

Side Door

Aim

To mesh the given side door model according to the given criteria

Procedure

• Before we can mesh the model, it is necessary to prepare the mid surface of the given model
• As this is a model with several surfaces having a varying thickness, we will need to manually extract the mid surface for several components
• First, we can extract the base of the model which has a constant thickness using manual offset in surface edit and using by face option

Figure 1

• In this portion before we can extract the rib,it is necessary to properly join the surfaces as they may not be properly attached
• To do this, we can use the line drag option to make the surfaces collinear and then extend the surfaces and trimming out the excess parts.

Figure 2

• The vector for line drag must be chosen carefully along the surface.

Figure 3

• After that, we can extract the rib and connect it to the surface appropriately

Figure 4

• Features such as the one above cannot be captured properly as such , so instead, it is better to at least capture the hole instead as shown

Figure 5

• The resulting manifold edges are unavoidable
• For generating the mid surface of the ribs, there are several methods available to us
• If the rib thickness is constant, we can simply offset it and extend it appropriately.

Figure 6

• If the rib has a varying thickness, the best option is to simply create a midline and then project the line to the base using the surface trim option and then create a new surface.

Figure 7

• For thickness assignment, we use the auto review thickness command as shown and use the average thickness.

Figure 8

• Mesh Criteria is given in table 1

S.N	Quality Criteria	Value
1	Aspect Ratio	5
2	Skewness	45
3	Warping	15
4	Taper	0.5
5	Min. Length	2 Units
6	Max. Length	6 Units
7	Min angle Quad	45
8	Max angle Quad	135
9	Min angle Tria	20
10	Max angle Tria	120
10	Tria %	10

• For meshing, it is best to mesh surface by surface and remesh/solve off elements appropriately.
• While splitting the surface into smaller surfaces for a better mesh, doing this on large components drastically increases the time taken to complete meshing.
• Opposite trias can be solved by dragging them and combining the elements using the Quality index commands.

Figure 9

Figure 10

• It is important to check for connectivity using the check elements option and visually checking each edge and solving them appropriately using the connect nodes option and equivalence option.
• It can be observed that hypermesh is not recognizing the hole below.

Figure 11

• To solve this,go to parameter file settings and delete the remove hole row in holes 2d and 3D.
• After this,you can delete the elements,project them to the hole and rebuild accordingly.

Figure 12

• Using the check edges option to verify the connectivity of the mesh.
• If any are does not have connectivity use the node replace option to solve it.

Figure 13

• Setting it to thick 1d elements helps visualize the free edges easier

Figure 14

• In cases of large areas, it can be a tedious process to replace the nodes individually.
• An alternative can be to use the mesh edit option to do the same.

Figure 15

Figure 16

• Another option if the mesh edit command does not work is to delete the elements around the area by creating a cut zone.
• Before this, set hypermesh to keep mesh mode as otherwise you risk ruining mesh flow

Figure 17

Figure 18

• After creating the surface delete the elements inside and project the outside elements to the boundary created.

Figure 19

• Set hypermesh back to advanced remesh and remesh the surface
• There should be no connectivity issues after this
• Proceed with the same process for all surfaces.

Figure 20

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Figure 22

Figure 23

• For automatic mid mesh thickness, go to mesh->assignàmidmesh thickness
• Change solids to surfaces and select the parent geometry.

Figure 24

• Select the mid mesh elements.
  
  Figure 25

Figure 26

Figure 27

• Select calculate thickness and hyper mesh automatically assigns thickness to the elements.
• Verify the thickness by comparing it with the parent geometry in shadow mode.

Figure 28

Figure 29

Learning Outcomes

• Automatic thickness assignment
• Using line drag/line ruler options to patch the mid surface
• Create cut zones to fix connectivity of the mesh
• Using mesh edit to solve connectivity
• Updating mesh thickness

Result

The given model has been meshed according to the given criteria.