Week - 4 - 2D meshing for Plastic components

Aim:

To solve the given plastic bottle cap clear the geometrical errors and take the mid surface by suitable mid surfacing techniques with good mesh flow.

Given data:

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
10	Tria Percentage	15

Following Method to solve:

1. Import the geometry of Bottle cap in ANSA.

2. Checking the geomerty errors and clear it all.

3. Extracting the Mid-surface

4. Project, Extent & intersect option used to individual surface connect to mid-surface.

5. Assign the quality Criteria.

6. Meshing & improve the meshing.

Procedure:

Import the CAD geomerty in ANSA:

¬ After import the cad geometry, first if all going check the geometry errors.

¬ There are some errors, give complete topology and fix the geometry errors.

¬ Then geometry clean up sucessfully.

¬ In geometry model grey colour indicates positive & yellow color indicates negative.

¬ Give orient to complete grey color before going to extract mid surface.

Extracting the Mid-Surface:

¬ In order to meshing the components need to mid surface for all surface involved in the components, it means have to convert 3d to 2d the components is called mid surface.

¬ Here i used offset and middle option to extract the mid surface.

¬ Check the thickness of components.

¬ Then using Extent , intersect options are used to connect all the ribs into the components.

Measure the thickness:

¬ Measure the thickness of all the parts of components.

Extract the Mid-surface:

¬ Extract the complete mid surface offset, middle, project options are used to create it.

¬ After create mid surface check the geometry also.

Extracting the Threads for mid surface:

¬ Using Middle option under the curve and select the two cons to create the mid curve between the selected two cons.

¬ Got the middle curve have to project the curve to mid surface, go for cons-select project options and select the curve and project in the mid surface.

¬ After project the curve on mid surface go to faces- new - create coons , select the curve and projected line then create the surface for the threads .

Extract the teeth:

¬ similar to the thread method usint the middle option under the curve and selected the two cons and create the mid curve.

¬ After that project the other end cons to the mid surface.

¬ Then go for faces- new- coons and create the surface.

Extent and intersect the individual surface:

¬ First used middle option under the faces are take middle surface of the parts.

¬ Then this aprt are not connected mid surface, so have to use extent and interscet options are helps to connect to the mid surface.

¬ After connected the midsurface that cons change single into triple cons.

Assign the quality criteria:

¬ Complete the mid surface creation then move to meshing.

¬ Before start meshing set some quality criteria as given in question.

¬ Each element in the should qualify the given quality criteria.

¬ After assign the given quality criteria check the topology and clean up before go to mesh.

Meshing and improve Mesh quality:

Meshing:

¬ After topology clean up strat meshing the each and every parts.

¬ There are lots of options are used , here using BEST mesh option to be meshed completely.

¬ Best mesh gives good mesh flow, its depends upon the perimeter value and decent mesh.

¬ once complete the mesh , then try to reconstruct the mesh, it hepls to get good mesh flow.

Imporove Mesh quality:

¬ To remove tria on edges, using split,swap option or else paste option are help to reduce tria.

¬ Off elements should be zero in order to achive the quality criteria.

¬ After complete meshing try clear the quality errors as well rotating tria remove all.

¬ give good mesh flow after complete the mesh

Conclusion:

¬ Completed the bottle cap meshed sucessfully.

¬ First bottle cap in converted 3d into 2d surface by extracting mid surface with given quality criteria give good mesh flow as well improve the mesh quality.

¬ Finally completed the bottle cap and saved as draw shell as solid.

Results:

¬ Draw shell as solid:

Final bottle cap model:

Learn out comes:

¬ Here learn analyze the model and extract mid surface for casted and plastic parts.

¬ Clear all geometry clean up as well complete topology.

¬ To assign quality criteria & check quality issues.

¬ Generate good mesh flow, as well improve the quality of mesh.