Bottle cap Extraction of midsurface and meshing in Ansa

Objective :

clean up the geometry of the model, taken up midsurface and do meshing of the bottle cap according to the quality criteria provided.

Procedure :

• perform geometry cleanup.
• extract midsurface of bottle cap.
• assign new pid to extract midsurface.
• performing meshing with the given quality criteria and mesh parameter.
• assigning thickness.

1. perform geometry cleanup

First import the CAD model into ansa database

fig. original geometry

so after then work in TOPO mode and give topo for entire geometry.

fig. after topo operation

After that delete the unwanted entities and run the geometry checkups to see the errors present in model.

fig. geometrical errors

As you can see there are lots of geometrical errors are available like needle face, collapse cons etc. so error can be rectified and corrected by manually or use of auto fix present in check-up bar .

fig. cleanup geometry

After remove topological error. we refine the geometry by changing the length of element to 1mm. this is done by using the length button under the perimeters in the mesh module .

2. Extract midsurface

The given model has variable thickness. Hence different midsurface extraction method are adopted.

Offset method :

Some of the part in the model are subjected to an offset method to extract there midsurface like outer circular face.

fig. offset method

Single middle method

some of the part in the model are subjected to single middle method to extract their midsurface like ribs.

fig. middle method

curve middle method

some of the part in the model are subjected to curve middle method to extract their midsurface like teeths.

fig. curve middle method

Extend tool under faces option in TOPO module is used to connect the single midsurface part which are separated from the base to pasted to base geometry for achieving proper midsurface of whole geometry.

3. Assign new pid to midsurface extracted

After midsurface we assign a new pid of extracted midsurface.

4. Meshing :

Prior to meshing ,mesh parameter and quality criteria were set according to requirement.

fig. Mesh parameter

fig. Quality criteria

Mesh the model according to given parameter.

Best and Batch meshing algorithm is to be used for meshed the model.

Errors in mesh are correctly by swap, split, reconstruction, smooth, paste feature.

At few region quality error could not be cleared due to geometry complexity.

5. Assign thickness to mesh :

After meshing we have to assign thickness to mesh by going in the property menu. here since we have varying thickness throughout the geometry, thickness will be different of each part

Final model :

Conclusion :

Mid-surface of component is achieved by using different type of manual midsurfacing method and the component is meshed according to given quality criteria.