Week 3
HOOD 2D Surface Meshing
Objective:
The objective of this project is used to check the Geometrical errors and meshing for the HOOD model using ANSA and also thickness has to be assigned to the Mid-Surface.
Understanding the sequence of steps to prepare the 2D mesh as per the Quality Criteria
- Saving the ANSA settings asper our requirement.
- CAD model or any 3D model.
- Converting the file Solidworks model or CAD model into IGS (any ANSA supporting format).
- Preparing the model for geometric clean-up.
- Generating mid-surface by using auto or manual mid-surface generation method.
- Assigning thickness and set part ID or property Id for the mid- surface.
- 2D meshing as per the Quality criteria given.
Geometrical clean-up:
Geometry is the tool which is available in the checks, it is to check the errors in the CAD model like triple cons, cracks, etc. before creating the mid-surface. Before going for geometry check perform the TOPO.
Tools → checks→ geometry→ execute→ fix the errors (some are auto fix and some are manual).
Manual fixing:
- Release the cons
- Delete faces or cons
- Inserting Hotpoint
- Topology or paste.
TOPO:
To perform the topology based on the settings in tolerance where it is required after manual fix of the geometrical errors.
Generating Auto mid surface:
After geometry clean-up creating mid-surface using mid-surface option by selecting the entire object at a time.
Hot point and perimeter points:
Assigning the length to set the nodal distribution of perimeter asper the value mentioned quality criteria then measuring the perimeter length is there any inconsistency between the hot points.
Mid-surface:
It is the operation to extracting the thin layer from the model using mid-surface from face tool.
- Geometrical checks
- Topo
- Faces
- Mid-surface.
- Set PID
Geometrical errors:
Repeating the geometrical checks on mid-surface before going for the meshing. This time we have to deselect the single cons.
2D surface meshing:
Hood consist of two bodies, to make it easy I have separated the hood into separate bodies to create the meshing operation.
Before performing the surface meshing it is very important that we need change the values in the quality criteria as general, mixed, 1st order and also mesh quality etc.
Features used to generate the mesh:
Mesh generation in mesh module we have selected best mesh for the hood model.
- Mesh Generation
- Best
- Shell Mesh
- Reconstruction
- Macros
- Cut
- Join
- Perimeters
- Length
- Number+ (-)
Quality criteria: To bring the node and mesh as per the values given in the quality criteria. We need to check the errors in the net like negative volume and minimum and maximum length of the net, aspect ratios
To bring the net consistent and uniform flow of net we need to reconstruct the mesh using shell mesh by reconstruction
To improve the Mesh quality we need use the following tools.
- Shell mesh
- Reconstruction
- Elements
- Split shell : To reconstruction the net to get uniform flow of net we have to split the shell
- Perimeter: to increase or decrease the nodal numbers of the perimeter
Conclusion:
2D surface mesh is done on both sides of the hood.it is marked as two different surfaces in the image and total trias reduce to 2.17% and quads to 97.23%.