Performing 2D meshing for three Sheet metal components within quality criteria.

• Choose the use profile as Hypermesh Radios. Click on Open.
• Use the geometry color mode and choose by Auto Mode.
• The component appears in wireframe mode. Change it o surface. At LHS we get the no. of component which we have to mesh. Here we have to we have to create component according to given geometry. namely

1. Geometry Cleanup

• Now we have fully equivalence mid surface. We have to clean the surface to get clean and clear meshing. It will avoid the pinholes, very small edge and surface fillets automatically. We have to set the parameters according to requirement.
• Go to defeature option and set the target fillets(max.radius and min.radius). Select the taget surface and hit on find. Hypermesh will automatically recognize the surface fillets not hot on remove. It will remove the fillets which we don’t want.
• Apart from that , Click on auto cleanup. Click on edit parameters. Se the parameters according to requirements. We have to decide it according to customer requirements and accuracy required.

Eg. Target Element Size= 5 as shown in picture.

• Now click on edit criteria. This is where we have to specify the criteria for the Quality index of meshing.
• These are the criteria on which our meshing gets checked on quality of meshing.

E.g. Min/ Max Size of element, Aspect ratio, Warpage, Min/Max Quad angle, Skewness etc

• Click on Apply and hit OK. Click on auto cleanup.

1. Defeature option

Now we have to remove the fillets from the surface geometry as the surface fillet can cause the element failure in various ways. The mainly we want to remove the fillets from the rib surface.

1. Auto Mid Surface

As the thickness of part 1 is uniform at every cross section we can use the auto mid surfacing.

Now select the manual mid surface option and hit the mid surface.

1. Meshing

• After auto clean-up click on 2D and click on auto mesh or hit F12 on keyboard as shortcut.
• Select the surface as displayed surface. Choose element size as per requirement. Here it is
• Use mesh type as Mixed. And hit the mesh button on screen.

• Adjust the nodes according to requirements. Make sure the mesh flow is good. Adjust each area of meshing with care to get a quality mesh. Hit middle mouse button to exit the mesh.
• Mesh flow near cutouts and at edge will specify mesh quality. Now meshing is done. It’s time to check the quality of the mesh.

1. Quality Check

• Click on quality index. It will show the no. of elements failing in quality criteria which we have specified previously.
• So the quality index will show the failing elements or worst elements in the meshing. We have to avoid these elements during meshing. We can overcome these elements by remeshing certain areas again which is a good way to do it.
• Click on F12 and select the elements. Select the element from the outer edge to remesh the surface.
• Make a square to remeshing. It will easy to remesh targeted area. This is way to get remesh all the surface again and again. Repaeting this procedure you will refine mesh.
• Now again we can check for the quality criteria. In quality index we can use the tools like place node, node optimize, element optimize, drag tria, split quad, combine tria etc
• These tools also help to get rid off from bad mesh.
• Place Node use to place a node at a required position. We can use element optimize to adjust the element as per meshing thresholds specified earlier. These options will adjust the element at minor level..
• Drag tria and combine tria are also used for removing tria from mesh or adding together to form a quad element.
• Apart from these entire tools smooth tool is used for very minor adjustments in the elements to complete quality criteria.
• After doing all this you will get a quality mesh which will pass all the quality criteria. In industry point of view the tolerance is given for quality criteria’s it may be in 5% to 10%.

Conclusion: Elements violating threshold are zero. So the quality of mesh is good. And we can decide good mesh quality based on the mesh flow as well. So below figure shows the good mesh flow. So we can conclude the meshing is of good quality.

Similarly we have to do the meshing for all the parts and follow the procedure to get good meshing.

1. Property Creation

• We have to create the property for the component created.
• In this case for plastic part the thickness should not remain the same. We have to specify the thickness as a property of a component.

1. Assigning Property and Material

• We have to assign the property and material to the component created. Click on component. Click on assign. Select the created property and material and hit apply.

We have to do the same procedure for other parts.

Conclusion:

1. Sheet metal parts have uniform thickness, so we can take auto midsurface.
2. Geometry cleanup is important. Toggle the unwanted edges to get proper surface.
3. Use of de feature tool is important to remove unwanted surface fillet and pinholes.
4. Meshing with shell elements as the thickness of part is less than 6mm.
5. Assigning a property that is thickness is important. Move the elements with respect to parent surface thickness. Choose the elements and move to respected collector.