Week - 4 - 2D meshing for Plastic components

2D meshing for Plastic components

Objective:

Using the provided quality standards, extract the midsurface, mesh the given bottle cap component, and assign the required thickness to the property.

Given quality criteria

S.No	Quality Criteria	Value
1	Target/Average length	1
2	Minimum Length	0.5
3	Maximum Length	3
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

Imported model

Figure. 1. shows the imported Plastic Bottle Cap model

Figure. 1. Imported Plastic Bottle Cap model

Geometry Clean-up

Geometry Clean-up of the model is done in the Checks Manager dialogue as shown in Figure 2. Using

Command: Checks + Geometry

Figure. 2. Checks Manager dialogue box before fixing

Auto fix is used to fix errors, while topo tools like new face, delete, and topo are used to fix any unfixed flaws. Figure. 3 shows the Checks Manager 100% executed dialog box.

Figure. 3. Checks Manager dialogue box after fixing

Quality Criteria

Assign quality criteria for the mesh by clicking quality criteria  tab then assign values in ths shells by checking the given parameters as per given data. Figure. 4. shows the Quality criteria dialoge box 

Figure. 4. Quality criteria dialoge box 

Midsurface

To extract the midsurface by the following commands.

For two surfaces with equal thickness. 

Command: Faces+Offset

Figure 5. shows the top body upper body

For varying thickness

Command: Faces + Middle + (single or multi).

For irregular quadrilateral (Such as threads and trapezoid)

Command: Curve+middle (To get mid curve of the threads).

Command: Cons+Project (To project the midcurve to midsurface).

Command: Faces+New (To create new surface).

Figure 5. upper body Mid- surface.

Figure 6. shows the Final Mid- surface

Figure 6. Final Mid- surface of Plastic Bottle Cap model

Assigning Thickness 

The midsurface thickness to be assigned. Since we have some surfaces with different thicknesses, we must gradually alter the thickness under each surface by the

Command: Property+New+Pshell+Assign thickness+Assign name.

Figure 6. shows the properties dialogue box

Figure 6. Properties dialogue box

Meshing

Before mesh generation assign peremeter lenght by

Command: Mesh +Perimeter + Length 

For Meshing select best mesh in the mesh generation using the 

Command: Mesh generation+Best

The mesh will be generated and it should be reconstructed  with

Command: Shell mesh+Reconstruct

To get quality mesh and to reduce tria elements by the following commands.

For element spliting

Command: Element + Split.

For element sjoining

Command: Element + Join.

For element refining

Command: Shell Mesh+Refine

Figure 7. shows the meshed model with nill off

Figure 7. Meshed Model

After completion of meshing, use Quality Criteria dialoge box in the Presentation Parameters check the Draw Shell as Solid as shown in Figure. 8.

Using this option allows us to view all elements as solid or in three dimensions.

Figure. 8. Checking the Draw Shell as Solid

2D mesh will be displayed as solid mesh according to given thickness of each midsurface as in Figure. 9.

Figure. 9. Solid Meshed Elements

Conclusion

The provided bottle cap model is meshed with the provided quality requirements using a midsurface and different surface thicknesses are assigned.