Week - 4 - 2D meshing for Plastic components

Question

For the given Plastic Bottle Cap model, check for the geometrical errors and take the mid surface by suitable mid surfacing techniques. PID and Thickness assignment has to be done for all the mid surfaces. Mesh the same with the given element Quality criteria.

Introduction

1. Objective:

The objective of this analysis is to perform meshing on a plastic component using ANSA and pass all quality criteria, geometry check and proper mesh flow.

CAD Model Image

2. Procedure:

Import CAD Model

· The CAD geometry was imported into ANSA using .igs format.

Check Geometry

· Removing all single cons available in model

· If the faces is deleted, creating new faces by selecting fitted option

· Removing attached two surfaces, by doing topo

· Orient is used to orient all surfaces into one direction

· If there is unchecked faces it should be cleared

· Finally Status shows 100% correct

· After doing these correction, model shown as below

3. Mid Surface Generation

· I have done Manual Mid surface generation for the model

· As it is a plastic component, it has varying thickness so we used Manual mid surface

· By using different option we had taken mid surface like Offset, Middle Multi, Middle options

· For teeth we taken mid using curve middle and create the surface, as shown below

· We use transform – Rotate option to create mid for n number of teeth

· Finaly Mid surface is done

4. Assigning Tickness for Geometry

· By doing Set PID , we can assign thickness for the mid surface and parent geometry

· By doing this, the separate property ID formed in PSHELL.

· We have created different PSHELL card for different component, as shown below

5. Meshing Process

· Setup the elemental length

· Edge of the hole should be parallel to the perimeter for proper mesh flow

· The hole should only having even number of edges

· check the fillets are passing to my length criteria, if not do defeaturing

· Assign the Quality criteria as given, as shown below

· Assign the mesh parameters like Target length, min length, as shown below

6. Meshing

· A 2D surface mesh was first created using quad elements, This ensured a higher quality mesh for the simulation.

· First mesh is done on critical feature, fillet

· Maximum tria element should be removed.

· There is a associate between mesh and surface

· When we move or remove mesh the associative from the geometry

· The mesh behaves independent of the geometry

· There is a some quality fails, because the triple cons is presented

· Even after reconstruction it also fails, because surface in projected to another surface, as shown below

· Mesh quality is improved using mesh tools in Classic Mesh Tap

· Like Elements(split, swap, join ), Grid(Move, Paste), perimeter(Num+/-) etc.

· I had done mesh for one side and do transform for symmetry for the model

· Finally best mesh is achieved.

Final Meshed Image

7. Learing outcomes;

ü ANSA Tools

ü Geometry cleanup for plastic component

ü Extract Mid surface of varying thickness use different comments

ü New comment like transform- Rotate for teeth and ribs

ü Mesh the plastic component with less tria concentration and proper mesh flow.

8. Conclusion

· In this report, the meshing process for the given CAD model in ANSA was successfully done.

· Meshing is done in proper mesh flow

· In this meshing process for the plastic component, ANSA great to create a high-quality mesh suitable for further Finite Element Analysis.