Mesh Cleanup on 2D SHELL Elements
In this Excercise we will be performing Mesh Cleanup on 2D SHELL Elements:
Objective:
To performing geometry cleanup operation by given models,
1. Practice
2. Mounting Bracket
3. Clip Repair.
2. Mounting Bracket
3. Clip Repair.
And extract the mid surface and clean mid surface geometry and create the 2D mesh with given target element length.
Then finally to assign the proper thickness to the mid surface by creating a generic property.
Introduction:
- CAE is the next step in not only designing a product, but also supporting the engineering process,as it allows to perform tests and simulations of the product’s physical properties without needing aphysical prototype.
- Hyper mesh is a meshing software. Meshing means diving the part or component into small fine parts. This process is called discretization. It’s important step in analysis of any component.Accuracy of Results of analysis depend on mesh quality and mesh.
2D Shell Element:
- Geometry defined by a curved mid surface defined with 3 or 4 nodes and thickness usually small compared to the two other dimensions. Generally rule of the thickness is less than or equal to 6. Mass of the element is distributed to the nodes.
Procedure:
Geometry cleanup
Geometry Cleanup tools allows to create and edit the surfaces as well as remove rounds, Fillets, Cutouts and Holes from the geometry. Topology is how to surface connect to adjacent surface of a part. Surface edge is associated with more than 1 surface, those surface are considered to be connected.There are four types of surface edges. That edges is Free edges, Shared edges, T junction edges, Suppressed edges.
Creating mid surface and creating 2D Mesh with Element Length:
Mid surface is created to the geometry. Most of the sheet metal parts and plastic parts have small thickness and hence has to undergo mid surface generation before meshing them. This process is reduce the meshing time as well as overall computational time. Process to create the mid surface,
- Geometry < Mid surface < Auto mid surface < Extract < Done.
Removing holes less than Diameter 5mm. Process to remove Holes,
- Geometry < Defeature < pinholes < Select the surface which has holes < Diameter (5mm)< Find and Delete.
There are many geometry lines around that hole and because of those, it\'s not possible to
place a washer there. To create washer around the hole before meshing the face containing the hole.While meshing we need a proper quad surface and accurate results during the analysis.
place a washer there. To create washer around the hole before meshing the face containing the hole.While meshing we need a proper quad surface and accurate results during the analysis.
- Geometry < quick edit < washer Split < select circle and tolerance < done.
Toggle split is change the edge type within tolerance. In geometry some face edge is not
correct shape so at that time to use the toggle split command correct that part.
correct shape so at that time to use the toggle split command correct that part.
- Geometry < quick edit < Toggle split < select the edges < give the tolerance.
Filler Surface is select a line on a free surface edge to recreate any missing surface. And
Replace point is move or retain a point. This tools are found in the quick edit panels.
Replace point is move or retain a point. This tools are found in the quick edit panels.
Then, Generate the 2D mesh into the geometry and give the element size was kept in 5mm
using same operation to have proper mesh flow. For quality checks you can remove the failing elements by going into quality index and then cleanup tools.
using same operation to have proper mesh flow. For quality checks you can remove the failing elements by going into quality index and then cleanup tools.
- 2D Mesh < auto mesh < select surface < give the element size < mesh.
Results:
Quality Check
The process of quality check let us know that the given requirement is meeting the given
target length element size is 5mm and minimum size is 3.5mm and maximum size is 7mm.That try to remove all the error which are present in the model and use the cleanup tools option rectifying the errors.
target length element size is 5mm and minimum size is 3.5mm and maximum size is 7mm.That try to remove all the error which are present in the model and use the cleanup tools option rectifying the errors.
This images shows the Clip Repair Mid surface with 2D mesh with target length 5mm, min
3.5mm and max 7mm.
This images shows the Practice Mid surface with 2D mesh with target length 5mm, min
3.5mm and max 7mm.
This images shows the Mounting Bracket Mid surface with 2D mesh with target length 5mm,
min 3.5mm and max 7mm.
Assigning thickness:
After getting the meshed parts are assign the thickness using the property option which is
equal to the thickness of parent geometry.
- Click model < select option (displayed on below model browser) < part < property < give thickness.
This images shows the Clip Repair meshed parts are assign the thickness is 0.9mm.
This images shows the Practice meshed parts are assign the thickness is 2mm.
This images shows the Mounting Bracket meshed parts are assign the thickness is 1.8mm.
Conclusion:
The given models are better examples for understood to how to clean up the geometries and
which commands are required to processing of clean up geometry topology then let us know about the extract mid surface and 2D meshing and assigning the thickness to mesh with most important to eliminate the min and max length errors.