Geometry cleanup and shell meshing of automotive hood

Aim:- To perform geometry cleanup, 2D meshing, quality check, and fixing the errors of the automotive hood model.

Procedure:-

• The hood model was downloaded and opened in ANSA

• Topology of the model was checked (TOPO<FACES<TOPO).

• Few geometric errors were diagnosed and they were fixed manually and few by auto fix option.

• The hood consisted of outer surface,inner surface,latch and hinge.Each part was assigned property and named accordingly.

• To check the symmetry of the model Rm.Dbl option was used (TOPO<FACES<Rm.Dbl).

• Mid surface was generated for each component.(TOPO<FACES<MIDSURFACE<SKIN)

• Since the model came out to be symmetric only half of the inner and outer hood were used for meshing.Other half of the hood was deleted.(TOPO<FACES<DELETE).

• One by one each midsurface was selected and the geometry was cleaned by removing unnecessary cons and simplifying the geometry.

• Once the geometry was cleaned, meshing operation was carried out of individual components by selecting small macros.(MESH

• After meshing,mesh flow was optimised and opposite trias were eliminated.And smooth operation was carried out(Mesh

• Once desired mesh flow was achieved quality parameters were fed (Click F11) and the quality was checked (Make sure hidden mode was selected).

S.No	Quality Criteria	Value
1	Target/Average length	5
2	Minimum Length	2
3	Maximum Length	7
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
10	Tria Percentage	15

• The failing elements for quality were fixed by reconstructing the mesh in local regions(Mesh
• Once quality criteria is satisfied the mesh is mirrored (Utilities<Copy<Symmetry).

• Thickness was applied to the shell elements (Presentation Parameters

Conclusion:-

1. The geometry was cleaned and the model meshed with shell elements with a target length of 5mm.
2. Quality was checked off the model and failing elements were fixed