To mesh the plastic bottle cap component according to given quality criteria and assign thickness in ANSA

Objective:- To mesh the given component according to the quality criteria given and also assign the thickness to the components.

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

Procedure:-

• Open ANSA and open the component file which is in ".igs" as provided.

• From the modules use topo, Topo -> Faces -> Topo -> select the entities.
• Also even the orientation of the component by using the "Orient" option which is under Modules -> Topo -> Faces -> Orient.

• Now check the entities for any geometrical error by using the "Geometry" option from the Tools -> Check -> Geometry (from the options select single cons also). If any error found it can be fixed automatically by right click on the error and click on the fix or it can be solved manually by using different options of "Topo" present in modules.
• From the "Utilities" menu, use the "measure" option to check the thickness of the component, as the component thickness varies different parts the midsurface has to extracted manually and assign respective thickness.
• Manual midsurface can be extracted two ways, either by using offset or middle option which is present in Module -> Topo -> Faces. Depending on the surface of the component and thickness the two different option can be used to accordingly. After extracting midsurface set PID by using Modules -> Topo -> Faces -> Set PID, as the component have a variable thickness so PID should be assigned to each extracted midsurface so that desired thickness can be provided.
• Starting from the bottom measure the thickness and offset it and close the gap of the surface using Modules -> Topo -> Faces -> New -> Existing surface.

• Similarly, extract the mid for middle and base surface and close the gap present on the extracted middle surface.

• The gap between the middle to bottom and base can be closed by creating new surface between them.

• Similarly, extract the midsurface of top surfaces and the ribs present on it.
• After extracting the midsurface, extend the surface to connect to their respective connected surface by using the "Extend" option present under Modules -> Topo -> Faces -> Extend.

• Now to extract the teeth, Modules -> Topo -> Curves -> middle, the middle option is to be used first to extract the midcurve of the 2 lines present on the front.

• The backend line is projected to the midsurface of the base using the "Project" option, Modules -> Topo -> Cons -> Project.

• Create a new surface using the midcurve and projected line to the base, it can be observed the teeth can be duplicated to do that "Rotate" option is used but before that axis of rotation need to be created by Modules -> Topo -> Points -> OnCOG -> select two circular lines, create two axis of rotation, now to use rotate option Utilities -> transform -> copy -> entities -> rotate, in the copy entities dialog box, Step will be the number of copies to be made, Click on X box and select one COG then click on dX box and select the second COG, Angle will be the total angle of the circle/total number of teeth i.e here 360/36 = 10 after that middle-click to accept. Extend the end of the teeth to its base.

• Now to create midsurface of the thread, use middle option present under the curve after obtaining the midcurve project it normal to the parent surface and the midsurface where the thread will intersect, by using the new option under faces create a new surface using the projected midcurve.

• The bottom ribs can be extracted using offset option present under faces and rotate option can be used to duplicate it.

• The outer side rib can be extracted using middle option present under Faces and then extended to the middle and base surface.

• After extracting midsurface perform geometry check of the midsurface (uncheck single con and triple con), if any error found it can be fixed automatically by right click on the error and click on the fix or it can be solved manually by using different options of "Topo" present in modules.
• Now before meshing set the quality criteria and the parameter by using "Quality Criteria" and "Mesh parameter" form the "Utilities". Also, set the length for the entities by Modules -> Mesh -> Perimeter -> Lenth -> for both Perimeter and Macro select the visible entities and provide the values.
• Mesh one by one the extracted midsurface by Modules -> Mesh -> Mesh generation -> Best -> Select the entities .
• The elements can be remeshed and rotating quads and off elements can be removed by using the option in Shell Mesh -> Reconstruction or using the option in Elements -> Split, Swap or combination of the mentioned process.
• To refine the meshed surface use "Smooth" option present under "Shell Mesh'.

• Once the mesh is done and all rotating quads are removed and the mesh is refined release the elements from the midsurface by Modules -> Mesh -> Elements -> Release -> select the elements -> middle mouse click to confirm.
• Now to view the shell as solid elements, in Utilities -> Quality Criteria -> Presentation Parameters -> Elemets -> check Draw shell as solid -> Ok

Result:-

Conclusion:-

So by completing this challenge, I learned how to extract midsurface of bottle plastic component which have variable surface and ribs and also how to mesh according to given quality criteria, after that how to perform the quality check and resolve rotating quad and trias for better mesh flow and also finally how to assign thickness.