Week - 4 - 2D meshing for Plastic components

2D Meshing of Plastic Bottle Cap

Aim:

To extract the middle-surface of the plastic bottle cap and mesh the same with, given element quality criteria as mentioned below and also assign a proper thickness to it.

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
12	Tria Percentage	15

Model:

Objectives:

• Generating the mid-surface from the parent component
• Performing a meshing operation on a middle surface as per element quality criteria
• Checking the element quality by comparing with given quality parameters and criteria and improve the quality by various options
• Assigning the material and proper thickness to it

Procedure:

• Import the model file by using open option in ANSA

• Upper part of Bottle cap

• Lower part of Bottle cap
• Use the Topo option to join the edges, for better visualization
• Now check the geometry for any errors like single con, needle face, crack surfaces using checks- geometry tool in menu bar. after that select execute and select all the errors and right click-fix to fix those errors.

Mid-Surface of teeth

• For rotating the teeth first, we have to create the axis of rotation, for creating axis of rotation we need two different point at Centre at a different height, for that we are using COG option in point buttons, select the circle having two different heights to create a centre point at different height.
• After creating the centre points, now we can go to rotate command, here we have to define angle and no of teeth to be formed, also here we have to define the axis of rotation by selecting two centre point that we created previously.
• Angle between teeth = 360 / no of teeth

Axis of rotation

Teeth on upper part of plastic Bottle cap

Middle surface of thread

Mid-Surface of upper part of Plastic bottle cap

Middle-Surface of Plastic Bottle cap

• once mid-surface of whole component is generated the next step is to again check for the error in the mid-surface.
• After creating the mid-surface, the next step is to create a mesh on a component, but before meshing we have to set the quality criteria and quality parameters as mentioned above

Mesh parameter

Quality Criteria

• After defining the mesh parameter and quality criteria, now we can start the mesh
• we are using best option in mesh panel to mesh the component

Meshed model of Plastic Bottle Cap

In PID mode

Final Meshed model of Plastic Bottle Cap

Learning Outcomes

• Understanding about manual mid-surfacing
• Understanding about plastic meshing
• Understanding about general difference between sheet metal meshing and plastic meshing
• Understanding about how to take a mid-surface in complicated regions

Conclusion:

The given bottle cap model is meshed with given quality criteria using midsurface

Model link:

https://drive.google.com/drive/folders/1F9_3tx_gXOHZYOPM1piSFctHj8BOO4SF