Tool Test 1

Aim

• To check the given models for geometrical errors and mesh with given quality criteria.
• To assign thickness to the mesh model.

The component as downloaded before the topo clean-up

Switch panel as downloaded before topoloy.

PROCEDURE

The models assigned were a plastic trim component and sheet metal component. The plastic trim was switch panel from a car door.

Step-1: To study the areas of the model.

The model-1 for the tool test was that of a switch panel from a car door. The model had 5 attaching points with supporting ribs on it. These points were cylindrical and inclined at an angle. A cylindrical depression with supporting ribs is there on the bottom side of the panel. Then there was rib running along the length of the panel with cuts.The model of component bieng checked.

As for the model-2 it was a sheet-metal component. It had many features that had been stamped and punched. There were around 30 horizontal semi circular cross-sectioned stampings on the surface. Then there are two attachment points with a near conical depression. It had 7 rectangular, 4 circular and 2 triangular punched holes.

Step-2: To do the standard geometry cleans-up.

To clean up the geometry initially geometry checks manager were run. The switch panel had no errors found on it.

Then on model-2 the geometry checks manager gave following errors

• Triple cons
• Needle faces
• Unchecked faces

To remove these errors triple cons were deleted and the rest was fixed using fixing option available in the software.

Then topo was performed to stitch all the surfaces together. All the surfaces was properly oriented.

Step-3: To create and prepare the mid-surface.

The switch panel was manually mid-surfaced. Each part was individually measured at new surfaces was offset. The mid surfaces were captured in a way that it captures the features most prominent regions. For example the support ribs on the cylindrical depression were captured by creating a middle curve on the circular surface and projecting onto the middle surface. A new surface was created using the now available cons.

the image shows taking measurment to create mid surface.

The image shows the procedure of creating midsurface for ribs.

Similarly mid-surfaces for all the features were captured using offset and middle options as needed. The individual mid-surface was then properly attached at necessary places using ‘intersect’ and ‘extension’. These resulted in triple cons on the mid-surface. Then each surface was assigned individual PID’s to get their thickness. The entire mid-surface was checked and CON’s that may have caused faulty elements were minimized to maximum using hybrid option ‘CUT’.

the image shows the mid surface bottom side, it has monting points and cylindrical depression with support ribs.

For model-2 mid-surface was generated automatically using ‘MID-SURFACE’ as the cad geometry was very symmetrical had a number of individual features. After crating the mid-surface the punched holes was inspected for the number of hot-points and made them even and marked them to avoid rotation elements during meshing. As done for the other model the cons on this model was checked in a way that it captures the features as good as possible without failing the quality criteria.

the image shows measurments taken at various points.

the auto generated mid-surface.

Step-4: To type in the quality criteria and establish the mesh parameters.

When the mid-surface was ready the quality criteria’s were typed in.

• Max length-6mm
• Min length-2mm
• Target length-4mm

The mesh chosen was a mix of tria’s and quads, because it yields better results.

the image shows the mesh parametrs.

theparametrs were same for both models.

Step-5: Meshing and checking.

For switch panel meshing was done for the features first and then to the plane areas was done later. Meshing features was done using best mesh. Additional hot points were deleted and mesh was reconstructed many times to get a proper flow of mesh. Plane areas were topologically cut into smaller ones and individually meshed to get a better mesh flow. These cuts had to be introduced at many places which were then removed without changing the established mesh flow.

the image shows the mesh on the impresson on the inside surface.

the triple cones kept giving off elements.

the meshing on sheetmetal component

Opposite trias were eliminated using "Split" and "Swap" after which the area was made proper again using "Smooth" for both the models.

the mehing was done for he above coponent in a similar way.

Step-6: Giving thickness to the mid-surface.

the sheet metal had uniform thickness of 2mm and the mid surface was assigned it. then the draw shell as solid was enebled.

the image shows the shell as solid.

for the switch panel .Each of mid-surfaces was individually selected and new shell property identity was created.Thickness correspondingly was given as their parent geometry.Each mid-surface was then given a new material.

the witch panel as solid.

conclusion

the tool test models provided a much needed insight into areas where there need to be imrovent. like how to mesh certain areas, which features to be avoided etc.

coparison between the CAD and FE model.

below provided are the links to the models on gogle drive.

https://drive.google.com/file/d/1pMJJ6cf49iAr74dJjJeqUx3u9XUhA6p_/view?usp=sharing

https://drive.google.com/file/d/19I9cCE2oRooMNrXK2dUqgz8htI5-4_8X/view?usp=sharing