Midsurface and meshing in accordance with the quality criteria using ANSA

OBJECTIVE:

To extract midsurface and mesh the geometry using the given quality criteria given below. Suitable thickness has to be assigned.

PROCEDURE:

1. The given model is imported in the ANSA software.

2. The hood outer panel components is extracted using 'OR' and stored in a lock. The quality of the outer panel is checked using Checks>>Geometry>>Visible>>Execute. The errors dialog box is shown in the figure below.

3. The hood inner panel components is extracted using 'OR' and stored in a lock. The quality of the outer panel is checked using Checks>>Geometry>>Visible>>Execute. The errors dialog box is shown in the figure below. The errors are fixed using autofix option.

4. Lock the current model i.e., Hood inner panel by hiding the hood outer panel in manage locks panel. After this step, go to Faces>>Rm Dbl>>Give the following options shown in the image below>>Ok.

5. Follow step 4 for the hood outer panel. This is done to reduce the time of meshing. Since there is a symmetry plane, the elements can be reflected along the symmetry plane once meshing is done.

6. Press F11>>Quality criteria dialog box opens>>Enter the necessary quality criteria. Go to Presentation Parameters>>Enter the details as shown in the figure below>>Apply.

7. Go to Faces>>Offset>>Select the faces>>Give Feature Area angle as 25 degrees>>Give the offset value as -0.375. After giving this option, give middle mouse button to confirm the selection. Do not delete the original faces.

8. Repeat step number 7, for hood outer panel with the same offset value.

9. The quality of the midsurface is checked using Checks>>Geometry>>Visible>>Execute. While using this option single cons option must be unchecked for checking. The errors found if any are fixed using autofix option.

10. Go to Mesh Module>>Perimeters>>Length>>Perimeters>>Select the surface>>Length: 5mm>>Ok. By doing this the perimeter of the geometry is adjusted to 5mm target element length. Go to Mesh Parameters>>Assign the target element size as shown in the figure below.

11. Go to Mesh Generation>>Best>>Select the faces to be meshed. An initial meshed model would be obtained. Go to Hidden drawing mode to see the quality criteria. If the quality criteria is not satisfied, the region specific to it is remeshed to arrive at the criteria. The remeshing and reconstruction should be done until the OFF elements are completely eliminated. After meshing, the entities are copied and reflected along the symmetry axis to arrive at the final meshed model.

12. Repeat the same steps for Hood outer Panel. The difference here is the fillet region present should be defeatured before meshing the geometry. Same steps to be followed as previous.

13. After completion of meshing, move the inner panel and outer panel to separate component collector using Set PID option. The suitable thickness of 0.75 mm should be given as shown in the figure below.

14. Press F11>>Presentation Parameters>>Check the option draw shell as solid. The view must be changed to PID to validate the assigned thickness. The solid shell is shown in the figure below.

LEARNING OUTCOMES:

By doing this challenge following options in ANSA are learnt.

1. Topology cleanup and midsurface using the faces, autofix and Rm.Dbl options.

2. Adjusting the geometry according to the element length using perimeter and faces options.

3. Assigning quality criteria according to the parameters given.

4. Cleaning up the mesh to obtain the necessary quality criteria using reconstruct, remesh, smooth etc.

5. Assigning thickness to the mesh by creating a separate PID for the midsurface.

6. Viewing the shell mesh as solid after creating a 2D mesh. This mesh is shown in accordance with the assigned thickness

CONCLUSION:

The given hood model is meshed in accordance with the quality criteria given. Suitable thickness is assigned to the model. The final meshed model is shown in the figure below.

Drive Link: https://drive.google.com/file/d/1B_cJ73d6QsgWY7c0u1QgENAgndNjVHwt/view?usp=sharing