Week 8-Challenge
Objective : To generate a 3d mesh for the following components that fulfills the element quality criteria as required.
Preocedure : 1)Housing :
For this component we will first generate 2d tria mesh and then convert it to 3d mesh with 3d tetras option.
Hence the following steps are followed for both components in this geometry namely :
- inner(red)
- outer(blue)
1) Geometry Cleanup :
Delete Solids : The first step is to hide all the other components so that only the above component is visible. Go to delete -->solids and select the entire component to delete the solid inside so that we are left with just the surface of the above component. Next we go to defeature-->duplicates and select the surface to see if there are any duplicated surfaces.In this geometry there are none.
Toggle edges : We will go to quick edit and toggle the edges that are close to each other that will violate the minimum element size criteria and fill surfaces as required to repair the geometry
Once we are satisfied with the resulting component geometry we will go for 2d mesh option.
2) 2d Mesh : Next we will generate the 2d mesh of the given component with element size between 2 and 7mm and target size of 5mm. and click on generate. We see that near this region elements minimum size criteria gets violated hence we toggle the edges.
In certain areas we toggle multiple edges to fit the 2d elements according to the size criteria and we improve the mesh flow using place node option in quality index.
In certain areas due to nearby edges we use place node to deviate the nodes slightly from their actual position to pass quality criteria.
To optimize 2d mesh and flow we perform the same functions as earlier.
Remeshing : Any areas where mesh is failing we select a block of elements and remesh them using QI optimize or normal mesh in automesh panel.
3) 3d Mesh :
Next we have to generate the 3D mesh. For this we go to 3d-->tetra mesh. Go to tetramesh parameters first and give tet collapse value of 0.15 as required in the question.
Next select tetra mesh option
Select either comps or elems and then click on mesh. The 3d mesh has now been generated. We once verify whether the 3d mesh has been generated or not by masking elements to see if there are elements present in the volume of the component as shown .
Next we go to tools-->check elems-->3d-->tet collapse to check the no of failing elements in tet collapse.
As there are no failing elements in tet collapse hence the mesh is successfully generated.
2)TETMESH_PM : For performing the meshing of this component, we try using two methods
- Generate 2d tria mesh and convert to 3d tetras
- Direct tetra mesh generation without individually making 2d elements
1) Geometry Cleanup :
Delete Solids : The first step is to hide all the other components so that only the above component is visible. Go to delete -->solids and select the entire component to delete the solid inside so that we are left with just the surface of the above component. Next we go to defeature-->duplicates and select the surface to see if there are any duplicated surfaces. For first method we will delete the solids
Toggle edges : We will go to quick edit and toggle the edges that are close to each other that will violate the minimum element size criteria and fill surfaces as required to repair the geometry
Once we are satisfied with the resulting component geometry we will go for 2d mesh option.
2) 2d Mesh : Next we will generate the 2d mesh of the given component with element size between 2 and 7mm and target size of 5mm. and click on generate. We see that near this region elements minimum size criteria gets violated hence we toggle the edges.
In certain areas we toggle multiple edges to fit the 2d elements according to the size criteria and we improve the mesh flow using place node option in quality index.
In certain areas due to nearby edges we use place node to deviate the nodes slightly from their actual position to pass quality criteria. We observer that many elements in the holes are violating the qaulity checks, so we treat them individually using save failed-->mask-->reverse and then perform element optimize or delete mesh and remesh them.
In this way we fix the 2d mesh using element index option in 2d panel.
3) 3d Mesh :
Next we have to generate the 3D mesh. For this we go to 3d-->tetra mesh. Go to tetramesh parameters first and give tet collapse value of 0.15 as required in the question.
Next we go to colume tetra and mesh as we did for the previous component.
After checking for tet collapse we find that there are zero failing elements.
Now we try with secod method for better capturing the geometry as in this method, the elements are a bit deviated from the geometry due to the big 2d element size.
Direct TetraMesh :
For this operation, we can directly mesh the component, by selecting comps in the tetra mesh menu and clicking on mesh.
As we can see the geometry is better captured in this model, but however the 2d elements do not meet the minimum element size criteria. On checking there are zero elements failing the tet collapse as well.
Chassis_assy :
For performing the meshing of this component, we try using two methods
- Generate 2d tria mesh and convert to 3d tetras
- Volume tetra mesh generation without 2d elements
1)Geometry cleanup : For this we will delete the solids for the components which we are going to 2d mesh first and then convert to 3d tria as we need only surfaces for 2d mesh generation.
Next we will go to quick edit and toggle the edges that are close to each other that will violate the minimum element size criteria and fill surfaces as required to repair the geometry
For the hub component ,we will remove the splines inside the inner diameter of the hub so that the mesh can be formed uniformly by deleting the surfaces and then extending the shaft to the flange, followed by toggle edge.
We also toggle all the edges for the chassis_links component that are not required and may disrupt the mesh flow.
2) 2d mesh : Next we will generate the 2d mesh of the given component with element size between 2 and 7mm and target size of 6mm. and click on generate. We see that near this region elements minimum size criteria gets violated hence we toggle the edges.
Similarly we generate the 2d mesh for the chassis_links component as well.
After optimizing the elements we ensure that there are zero failing 2d elements for the surface mesh.
3) 3d mesh : Next we have to generate the 3D mesh. For this we go to 3d-->tetra mesh. Go to tetramesh parameters first and give tet collapse value of 0.15 as required in the question. Next we go to volume tetra and mesh as we did for the previous component.
After checking for tet collapse we find that there are zero failing elements. Hence we are satisfied with the 3d mesh generated for hub and chassis_links.
3)Volume Tetra mesh :
Geometry Cleanup : For the remaining two components we see that as their geometry is a bit complex, expecially with upright, there are many intersecting surfaces and few issues with the geometry. Hence we will not delete the solids in these components and directly go for volume tetra mesh.
3D mesh : We will select volume tetra option in 3d subpanle and select the solids as shown.
Upon checking the tet collapse value we find that there are few failing elements in this criteria. So we go to 3d-->tetra mesh-->fix 3d elements.
We select the elems, click on remesh, select the suitable options and click on fix. After doing this, we find that the elems failing tet collapse have now been repaired and we have zero failing elements.
In this way we have successfully meshed all the components with 3d elements using all the different methods available to us.
However upon trying to save we get the error maximum number of nodes exceeded. So we Delete half the geoometry as it is symmetric about the y-axis and can be reflected later if required.
Conclusion : the components have been meshed according to the given quality criteria as required.
Link for submission : https://drive.google.com/file/d/1Lvzp-S4xfljfptz45prj3WGw62caJTnZ/view?usp=sharing