Week 3 - 2D meshing for sheet metal

Aim: For the given geometry of the hood model. take the mid surface for all the components after checking the geometrical error and mesh the mid surface with given element quality criteria. (Refer to the table below for the quality criteria)

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

Procedure:

1. Import Model
Open the given file (Hood_model1.stp) in ANSA, the given hood model has 4 components:
check the uniform thickness of the geometry.

Inner Extract (0.75)
Outer Extract (0.75)
Hinge (1.2)
Latch (1.2) of uniform thickness

2. Geometry Clean-up:
The components are checked for geometry clean-up using Checks > Geometry and clean up the errors using an auto fix and use
topo tools like a new face, delete, and topo, etc. to achieve 100%.

3. Mid–Surface Extraction:
Manual mid surfaces are extracted by selecting the faces of each component by offset option by giving the distance half of
the thickness.
For symmetrical components, only part of the component is extracted.
Mid Surface Geometry is again checked for errors.

Outer Extract (Mid surface):

Inner Extract (Mid surface):

Latch extract (Mid surface):

Hinge Extract (Mid surface):

4. Meshing
The Mesh parameters and Quality Criteria as per the given are entered.

Cons and Hot points are altered according to fit the criteria, i.e., for hemming surface cons are joined to avoid failing
minimum shell length using cut and join of macros tab.
Perimeter and macros are set for 5mm using the length in the perimeter option of the mesh tab.
Each Face(macro) of each component is meshed using the Best option in the Mesh Generation.
Mesh Quality is improved using reconstruct option in Shell mesh.
Further failed elements and tris are removed using Split, Swap, Join (Elements Tab), Smooth (Shell mesh tab), Paste
(Grids) and Num +/- (perimeter tab).
The Symmetric surfaces are reflected using transform -> copy option (Symmetry -> Working plane).

Outer extract mesh:

Hinge extract mesh:

Latch extract mesh:

Inner extract mesh:

Hood Model Final Meshed:

CONCLUSION:
Performed manual topology cleanup, mid-surface extraction, and 2D meshing of the given model.

mesh the component satisfying Quality Criteria with better mesh flow.

Successfully meshed the component based on input quality criteria.