Hypermesh purojeet

Objective1: To create Tetra mesh for Housing model according to given element criteria

Criteria: Elements sizes: Min- 2mm, Target- 5mm, Max- 7mm, Tet collapse: 0.15

Procedure:

1. A new Opti struct format file was opened in Hypermesh, housing CAD model was imported.
2. First all the solids were deleted from the parts, then surface geometry was checked for surface defects and fillets and other feature with radius less than target element size were defeatured using defeature option in geometry window.
3. Surfaces were again checked for geometrical defects and clean up was done where ever required.
4. The two model surfaces were meshed separately, first 2D mesh with tria elements were created according the given quality criteria. The mesh was checked for failed elements using check elements tool, necessary corrections were made failed elements using element edit tools.
5. After creation of 2D shell elements, 3D tetra meshing was done on the model using the 2D elements. Similar process was followed for the second model also
6. At the end the 3D tetra mesh created were checked for Tet collapse (defect generated when the height of tetrahedron 3D element is less than the target element length). Tet collapse defect were cleared by re meshing the failed elements and changing the height of tetra element by translating nodes.
7. All the Tet collapse can not be cleared because it will affect the arrangement of tetra elements in a 3D mesh.

Results:

Housing model after defeaturing:

Housing after 2D meshing

Hub after defeaturing:

Hub after 2D meshing:

After 3D meshing housing and hub

Objective2: To create tetramesh for crank hub

Procedure:

1. A new file in Opti struct format was opened in Hypermesh, crank housing model was imported.
2. Surface geometry was checked for defects and fillets below the minimum element length were defeatured, again surface was checked for defects.
3. 2D mesh with tria elements were created according the given quality criteria. The mesh was checked for failed elements using check elements tool, necessary corrections were made failed elements using element edit tools.
4. 3D tetra mesh created were checked for Tet collapse (defect generated when the height of tetrahedron 3D element is less than the target element length). Tet collapse defects were cleared by re meshing the failed elements and changing the height of tetra element by translating nodes.

Results:

Crank hub after defeaturing:

Crank after 2D meshing:

Crank housing after 3D meshing:

Objective3: To create tetra mesh on the Chassis assembly geometry

Procedure:

1. A new file in Opti struct format was opened in Hypermesh, chassis assembly model was imported.
2. All the solids from the model was deleted, each part surface was checked for geometrical defects and small fillets, the defects were cleaned and fillets below minimum element size were defeatured.
3. As this is a symmetrical model only one of each part were used for meshing.
4. All the model surfaces were meshed separately, first 2D mesh with tria elements were created according the given quality criteria. The mesh was checked for failed elements using check elements tool, necessary corrections were made failed elements using element edit tools.
5. After creation of 2D shell elements, 3D tetra meshing was done on the model using the 2D elements. Similar process was followed for the other models also.
6. The 3D tetra mesh created were checked for Tet collapse (defect generated when the height of tetrahedron 3D element is less than the target element length). Tet collapse defect were cleared by re meshing the failed elements and changing the height of tetra element by translating nodes.
7. The mesh of each part was reflected to its symmetrical counter part one by one using reflect option.

Results:

Chassis assembly after deletion of solids and defeaturing

Chassis assembly after creation of 2D and 3D mesh

Whole chassis assembly after reflecting the mesh.

Conclusion

• By completing this challenge , Learned the methodology of creating 3D tetra mesh for solid components