Week - 4 - 2D meshing for Plastic components

OBJECTIVE:

To extract mid surface and perform meshing as per the quality criteria given below using ANSA.

PROCEDURE:

1. The given model is imported into the ANSA software. It is shown in the figure below.

2. Go to Topo>>Faces. Select the Topo option and apply it to the given geometry. After this step, select the checks manager and check for the geometrical errors present in the model. This is shown in the figure below.

3. To fix the error auto-fix option is used. If the error is not fixed using auto-fix, then suitable options under the TOPO module are used for cleaning the geometry. Go to MESH module>>Perimeters>>Length. Set the perimeter and macros to 1. This is shown in the figure below.

4. Now go to Utilities>>Measure. Measure the geometry at different places to get the thickness of the geometry. After this process, various PIDs are created as per the thickness obtained. This is shown in the figure below.

5. Now extract the middle surface of the ribs using the middle option under the TOPO module. The cylindrical faces mid-surface is extracted using the offset option. This is shown in the figure below.

6. To extract the middle surface of the internal ribs, two circles of COG point are created. Using this transform option is performed using the extracted middle surface of one rib. The angle is calculated by dividing the angle of a circle by the number of ribs.

7. The internal spiral rib is extracted using the curves option under the TOPO module. The extracted curve is projected in the surface and a middle surface is created using this curve. This is shown in the figure below.

8. The extracted middle surface for the whole geometry is shown in the figure below.

8. The quality criteria are set as per the objective. The mesh parameters are given accordingly. This is shown in the figure below.

9. The surface is selected and the best mesh is deployed which is shown in the figure below.

10. Since there are quality errors obtained near the ribs area, the ribs are cut near the end to avoid the error. This is shown in the figure below.

11. The quality errors are fixed using the move, paste, origin, fix quality, reconstruct, smooth, and reshape options under the MESH module. The final mesh obtained is shown in the figure below.

12. At some errors the quality error cannot be fixed since the features share a common edge. Defeaturing also cannot be done in those areas. This is shown in the figure below.

13. The final meshed model with thickness is shown in the figure below.

LEARNING OUTCOME:

1. The geometrical error fix using the TOPO module is learned.

2. The manual middle surface extraction technique is learned.

3. Use of the transform option for replicating similar features is learned.

4. Meshing techniques and quality correction techniques are learned.

CONCLUSION:

The middle surface is extracted for the given geometry and mesh is generated as per the quality criteria mentioned in the objective. Hence, all the objectives are satisfied.