Assignment 1

Assignment -1

The objective of the assignment 1 is to clean up the three geometries given and create midsurface. Then a proper mesh needs to be generated with the prescribed size.

1.Geometry Clean Up:

1. After loading the geometry converting it into 2D Topo we can see red lines they are incomplete. We can convert them into complete surfaces using filler surf command from the quick edit menu.
2. If the red line is a free edge then the edge can be sorted by using toggle edge from the quick edge menu. The usage of the following options is shown in the pictures below.

(a) before (b) After

(c) (d)

For the images c and d the same command toggle edge is used but the tolerance is changed from 0.001 to 0.1.

3. If there is any gap in the surface, we can use filler surf option to create the surface. The usage of the following command is shown in the pictures e and f.

(e) (f)

4.After removing all the free edges and cleaning up all the geometry we can create a midsurface from the midsurface option. After selecting midsurface option, we have to select the component and hit the extract button. It will create midsurface.

(g)

The picture above shows a midsurface extracted of given part1.

5.We have the midsurface extracted from the component have excessive points can be removed using add or remove excess points option.

6. The smaller edges of the mid surface can be removed by using replace points option.
7. Smaller holes are covered up using filler surface and the later the edges are toggled using the toggle edge option.

After cleaning up the geometry and the midsurface we are ready to proceed for the meshing of the component.

Tools used: toggle edge, filler surf, add or remove points and replace points.

2.Meshing:

1. To create a neat and structured mesh the complicated surface is divided into smaller faces at complicated edges. This can be done by using split surface line and split surf node.
2. Once the splitting of the face at required areas is done we can proceed for meshing. For meshing we can use quick mesh which is in 2D radio button option.
3. We can select the surface and give element size required and the mesh is generated.
4. The mesh is generated with QUAD and TRI elements.
5. The smooth option is used to reduce the distortion of the elements and to improve the mesh flow. We can select the smooth option and select the target elements and hit smooth button.
6. Special care need to be taken for the elements around the holes. We can adjust the number of elements and element size to get a good mesh.Care is taken to have even number of elements around the holes.
7. Similarly we can use attach to surface ( Shift+F11) to attach the mesh to the given surface.For meshing certain (part 2) geometry ruled option is used in which the nodes are selected from where the meshing starts and the lines are selected to which we need to mesh and the mesh is generated.
8. If two triangle elements needed to be combined we can go to the edit element option and the select the combine option. After selecting we can select two triangles and we can make it into a quad.
9. After meshing if the mesh flow is not good we can do remesh we have to go to mesh option and select elements and convert them into quads and remesh. This will ensure the mesh flow in the geometry.