Week - 4 - 2D meshing for Plastic components

2D Meshing for Plastic Component (Plastic Bottle Cap Model)

Objective = The objective of this project is to find the mid surface of given Plastic Bottle Cap Model and its components after checking the geometrical errors and mesh the mid surface with the given element Quality Criteria.

Quality Criteria : Quality Criteria Shown in table no. 1.

Table 1. Quality Criteria Table.

Sr. 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
12.	Tria Percentage	15

Procedure :

• Import Cad Geometry = File -Open -Select Geometry.
• The given CAD Geometry imported in ANSA workbench and orientation checked.
• 

• Image 1: Imported CAD Model (Plastic Bottle Cap)
• Geometry Clean-UP = Tools -Checks -Geometry. Errors are resolved automatically by using fix command in geometry.
• Image 2: Before Geometry Clean-up
• Topo - Faces - Topo Command used to clear issues with the orientation
• All geometrical errors are cleared using auto FIX option.
• Image 3: After Geometry Clean-up
• Thickness Measurement : Thickness measured using Utilities - Measure. As this is a Plastic Component it has varying thickness thoughout the modal as shown in Image 4.

Image 4: Thickness Measurements

• The resolution of CONS improved using Mesh - Length - Perimeters - Macros.
• Topo - Faces - Offset, Topo - Faces - Middle used to find the mid surface.
• Also Topo - Faces - New / Cut, Topo - Cons - Project, Transform - Copy - Rotate Commands used to find the mid surface.
• Image 5: Mid Surface
• New part ID created for generated midsurface.
• Mesh Generation : The perimeter elemental length is set using Mesh - Perimeter - Length option.
• Image 6: Quality Criteria-Presentation Parameters
• The Quality Criteria Shown in table no. 1 are applied to the model using utilities - Quality Criteria
• Mesh Parameters are applied using Utilities - Mesh Parameters.
• Image 7: Mesh Parameters
• F11 Function Key is a shortcut for Quality Criteria - Presentation Parameters.
• Mesh is done using Mesh - Mesh Generation - Best.
• For better results of mesh Mesh - Shell Mesh - Reconstruction used.
• Image 8: Mesh Generated
• Mesh Improvement is done using Reconstruct, Smooth, Split, Swap, Paste, Cut, Join etc under Mesh tab.
• The surfaces are split to get better mesh flow using Mesh -Macros -Cut.
• Image 9: Meshed Component with Quality Criteria
• To reduce the mesh errors Trias coming towards the edge and trias going away from the edge should be avoided.'
• In order to assign the thickness to the hole model the solid mesh of the parts check the Draw Shell as Solid option in quality criteria under the presentation parameters tab were used.
• Image 10: Pre-processed Component Solid Meshing
• Result : The given Plastic Bottle Cap Model is meshed as per the quality criteria.
• Conclusion : From this challenge I learned about Plastic Component CAD model import, Geometry cleanup, New PID creation, Mid surface extraction, setting up Quality Criteria, Mesh generation, Reconstruction of mesh using quality criteria and how to draw shell as a solid.