Comparison of between manual meshing and automatic meshing and analyzing the obtained results.
Objective:
Perform CAD model check and implement batch meshing, obtain mid surface using skin and casting according to the required quality criteria and compare the obtained results.
|
S.No |
Quality Criteria |
Value |
|
1 |
Target/Average length |
3 |
|
2 |
Minimum Length |
1 |
|
3 |
Maximum Length |
5 |
|
4 |
Aspect |
3 |
|
5 |
Warpage |
15 |
|
6 |
Skewness |
45 |
|
7 |
Jacobian |
0.7 |
|
8 |
Minimum Quad Angle |
45 |
|
9 |
Maximum Quad Angle |
135 |
|
10 |
Minimum Tria Angle |
30 |
|
11 |
Maximum Tria Angle |
120 |
|
10 |
Tria Percentage |
15 |
Procedure:
1. Import the CAD model of the component into ANSA interface.
2. Perform an intial geometry check and fix the errors if any.
Intial check:
Final check:
3. Visually check the orientation and rectify if any descrepancies arise.
4. Check the thickness at random sections of the model.
5. The model will be meshed by three different methods.
Mid surfacing using skin option:
Mid surface of the component is obtained by automatic midsurfacing (skin). The thickness for the component is 1.0mm. By using the mid surface command, original component is deleted and a new PID is generated as a skin.
After generating mid surface, another geometry check is done to make sure all the connections are correct.
Once the mid surface has been acheived the hole features were adjusted to industry requirements and marked so that they would not change their orientation during meshing the model. After mid surfacing, meshing is done according to the given quality criteria.
Component as a solid:
Manual mid surfacing and using batch mesh option:
Using offset command, mid surface is generated for the component at 0.5mm. The mid surface generated is isolated and saved as a new PID.
Topology is performed on each component individually.
After generating mid surface for each component, another geometry check is conducted.
Batch meshing is implemented on to the component according to the quality criteria. It is an automatic mesh generation algorithm predefined in the ANSA software.
Component as a solid:
Obtaining mid surface and mesh generation using casting:
Casting is an automatic mid surface and mesh generation method using a single command. Since both the operations are taking place simulataneously, its mesh quality is not that accurate compared to manual meshing.
Component as a solid:
In the mesh interface, quality criteria and mesh attributes are assigned as required. Geometry changes as required are performed on the features of the component. Quality check is performed on the generated mesh. Mesh is adjusted accordingly such that it obeys the required quality criteria.
Mesh clean up is done using the combination of following commands as and when required:
1. Reconstruct
2. Delete nodes
3. Cut
4. Smooth
5. Split
Conclusion:
Resulted mesh obtained from the casting method was the quickest but not the most accurate one. Where as mesh obtained using the batch mesh option provides a better mesh flow but still the number of failing mesh elements were on a higher side. Hence, it can be concluded that even though manual mid surfacing and manual meshing will require higher amount of time but they will be best way to obtain the most accurate result.
Hot points were added, removed and moved as required to obtain uniform mesh as much as possible. Final mesh obtained was error free and satisfies all the required quality criterias.
Therefore, the model of the component is ready for further structural analysis.