Meshing of Plastic Container Model

AIM

Perform meshing of Plastic container model with element quality criteria:

Element quality criteria :

S.N	Quality Criteria	Value
1	Target Element Length	5
2	Aspect Ratio	3
3	Skewness	45
4	Warping	30
5	Taper	0.5
6	Min. Length	3mm
7	Max. Length	7mm
8	Min angle Quad	45
9	Max angle Quad	135
10	Min angle Tria	30
11	Max angle Tria	110
12	Tria %	15

Procedure

• Import the geometry and check for geometrical error which need to be corrected .
• Generate a mid surface by auto mid surface feature.
• Clean up the geometry for any kind of imperfect surfaces and unnecessary lines or points.
• After that mesh the component as per the quality criteria starting from one side of the surface to another side.
• After meshing the total component, assign the thickness as per the original parent geometry.

Step:1

The given component has beenimported into the hypermesh with Optistruct profile.

After that any solid from the surface is deleted from the components. After that we looked for any geometrical error by visualizing the toplogy of the components.

As there is no toplogy error, we moved on to next step is extracting the midsurface. But before that criteria file steup is done according to our requirement.

Step 2:

After geometrical cleanup next step is generate the midsurface for meshing.

Midsurface modeling is a technique for creating a simplified shell representation of a solid model.

Midsurface modeling can reduce the computational expense of analyzing a complete solid model when a shell model with a defined thickness and fewer details is suitable for the required analysis.

Midsurface gemeration by the Geometry toolbar provided in the hypermesh.

The component is a plastic container with a number of ribs of varying thicknesses. Generate the mid-surface for the geometry by a suitable method. Manual mid-surface was used for mid-surface extraction.

We have selected automidsurafe option with offset+planes+sweep midsurface option present with the model. After midsurface we have divided the components in various components to get ridof the automesh internal surface error.

After midsurface we get the following components.

Step 3:

Next step is meshing the components.

Meshing is an integral part of the engineering simulation process where complex geometries are divided into simple elements that can be used as discrete local approximations of the larger domain.

The mesh influences the accuracy, convergence and speed of the simulation.

We have generated 2D mesh, for meshing.

After meshing we get the following components.

Step 4:

After meshing the components consists of bad elemens which doesn't meet the criteria. This is shown below:

The geometry consist of 1754 bad elements , this can be cleaned by using the cleanup tools.

These elements need to be cleaned to get the requirement mesh criteria.

The failed elements can be fixed using the element fixing tools in the quality criteria menu.

While using the quality criteria menu the failed elements are highlighted in yellow and red colours.

Yellow errors indicate that the errors can be fixed easily, whereas the red colour indicates critical errors.

Result

After cleaning we get the final components but it consists of few bad elements its because of skewness at sharp corners which can't be cleaned.

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Conclusion

• Midsurface has been successfully extracted from the components and 2Dtetramesh has been successfully performed.
• Given meshing criteria has been followed for the given commponents while meshing.