Week 12 - Project-1

Objective: To mesh the given side door assembly model with a target element size of 4mm and satisfying the other quality criteria such as warping skewness, aspect ratio, taper, min angle quad, max angle quad, min angle tria, max angle tria, and tria percentage as provided in this challenge.

Procedure: Start with selecting RADIOSS as the solver

This assembly consists of one side door different parts which will be divided into 4 parts. So four different mid surfaces have to be extracted and meshed separately.

To extract the midsurface:

• Go to delete> select feature as solids> select all solids> if any solids are present they will be selected > delete entity
• Go to distance [ press F4 ] > select two points > then select the two points from the top and bottom layer > distance is 2.8. This method is used to measure the distance at all the points between the top and bottom layers and is seen to be 2.8.
• Go to geometry > surface edit > offset > select all the surface from one of the layers and then duplicate it > then offset it by a distance 1.4 towards the midsurface normal.
• If there is any surface that is not captured then follow the above steps for that surface and offset them. Then toggle the edges with the appropriate tolerance so that they combine and form the original/ appropriate midsurface.
• For the ribs, defeature the fillets and then measure the thickness of it. Then offset one surface of the ribs to half of the distance to obtain its mid surface.
• This extracted mid surface is given below:

To mesh the bodies we follow the same steps: geometry cleanup, surface division, fillet defeature (if less size less than minimum element size), automeshing, mesh edit, and assigning thickness.

• To perform geometry cleanup we go to geometry > quick edit > use features as replace point, add/remove a point, and toggle edge.
• Then surface division to ensure that more quad are present and trias are reduced providing the mesh flow. This is done at the curved surface edges. It also helps us to have more control over the mesh while using automesh. This can be seen is the above midsurface image. To do this we use the tools such as split surf node-node, split surf node-line, add points on a line, and project points. These tools can be are found in the quick edit tab.
• Measure the thickness of the fillets, if they are less than the minimum element length then they can be removed using the defeature tool. Go to geometry> defeature> surface fillets> assign the appropriate radius of the fillet > click find > then remove fillet.
• After this is successfully done we can proceed with meshing. While using the above step none of the parent geometry lines can be removed.
• Go to 2d> automesh> select surface > set element size to 4mm click mesh. Adjust the node density to obtain better flow and reduce trias in the mesh. After this, if there are any opposing trias then remesh them using the elemental automesh and set to the element type to quads(depending on the case to remove the trias).
• To edit mesh even further we go to quality index > click cleanup tools > use methods such as place node, drag trias, node optimize, split quad, smooth and others to edit mesh.
• Elements can also me edit by using the edit element in the 2d option. This can be used to create, combine, and split elements.
• When an appropriate mesh is obtained for the selected surface move on to the next and mesh them. Use the above methods to mesh all the surfaces for the part.
• Then we Go to edit edges > click find edges > select the elements around the unwanted edges then click the preview equivalence. A few points will appear then click equivalence. Thus the free edges will be removed.

Following the above steps will give the following mesh:

To apply thickness:

• Measure the distance (by clicking F4) between the upper and the lower layer of the side door. Do the same for all the ribs too.
• The ribs and parts with different thicknesses are stored as different components.
• Then create properties. Right-click > create > properties > input the thickness value.
• Now go to the component having that thickness and assign the property at prop_id.
• Do this for all the components.

Result: The Given model was meshed using the above procedure. The target was to obtain a mesh with appropriate mesh flow and proper tria placements along with the satisfaction of the quality criteria.

Google Drive Link : https://drive.google.com/drive/folders/1JH6esmET4cMMMolFC7Ff0Cb-iZPHD28u?usp=sharing