Challenge

3D Tetra Meshing For Suspension and other Geometries using Hypermesh

Objective: To Cleanup the Geometry and Tetrameshing For each Component and Maintain Quality Criteria.

Step 1 - Import the Model:

In this step, I will open and view the model file.

Image (1)

Step 2 - View The Model

In this step, I will view the model to evaluate its integrity.

Observe where the model has incorrect connectivity and missing or duplicate surfaces.
To open the Auto Geometry Cleanup panel, click Geometry > Autocleanup from the menu bar.
The surface edges are now colored according to their topology status. This occurs because of Geometry Colors is set
To display the model\'s geometry in wireframe mode, click on the Visualization toolbar.

Step 3 - Delete the Extra Surface (Fillet)

In this step, I will delete the surface that overhangs the round corner.

Image (4)

To open the Delete panel, click Geometry > Delete Surfaces from the menu bar, or press F2.
Optional: If you opened the Delete panel by pressing F2, set the entity selector to surfs.
Select the overhanging surface shown in the previous image.
Click delete entity.
HyperMesh deletes the selected entities.
To exit the panel, click return.

Step 4 - Create and Fill the Surface -

In this step, I will create surfaces to fill large gaps in the model.

To open the panel from which you can create a surface, click Geometry > Create > Surfaces > Spline/Filler from the menu bar.
Clear the Keep tangency checkbox.
Set the entity selector to the lines.
Verify the Auto-create (free edges only) checkbox is selected. The Auto-create option simplifies the selection of the lines bounding the missing surface. Once a line is selected, HyperMesh selects the remaining free edges that form a closed loop, and then creates the filler surface.
Zoom into the area indicated in the following image.

Image (5)
Select one of the red lines bounding one of the gaps (missing surfaces) shown in the previous image.
HyperMesh creates a filler surface to close the hole.
Repeat Step 6 to create a filler surface in the other gap.
To exit the panel, click return.

Step 5 - Set the Global Geometrical Cleanup tolerance

In this step, I will set the global geometry cleanup tolerance to .01.

Press O to open the Options panel.
Go to the geometry subpanel.
In the cleanup tol = field, type 0.01 to stitch the surfaces with a gap less than 0.01.
To exit the panel, click return.

Step 6 : Create a Tetra Mesh using Volume Tetramesher

In this step I will use the volume tetra mesher and equilateral triangles to create a tetra mesh for the cover.

Open the Tetramesh panel by clicking Mesh > Create > Tetra Mesh from the menu bar.
Go to the Volume tetra subpanel.
Set the Enclosed volume selector to surfs.
Select one of the surfaces in the model.
Verify that the 2D type is set to trias and the 3D type is set to tetras. These options control the type of elements that HyperMesh creates for the surface mesh and solid mesh of the part.
Verify that the toggle is set to Elems to Currrent Comp.
Verify that the Use curvature and Use proximity checkboxes are clear.
In the Element size field, type 10.
Click mesh.
The tetra mesh is created.
If the model\'s mesh lines and elements are not shaded, click on the Visualization toolbar.
Inspect the mesh pattern that the volume tetra mesher created.

Step 7: Review the Connectivity and Quality of the Mesh

In this optional step, I will review the connectivity and quality of the tria mesh to validate its integrity for the standard tetra mesher.

I will use the Edges and Check Elems panels to make sure that there are no free edges or very small angles in the tria shell mesh.

Open the Edges panel by clicking Mesh > Check > Components > Edges from the menu bar.
Verify that the entity selector is set to comps.
Select a tria element on the hub component.
The entire component highlights.
Click to find edges.
The status bar displays a message that reads, \"No edges were found. Selected elements may enclose a volume.\"
Note: The tetra mesher requires a closed volume of shell elements.
Return to the main menu by clicking return.
Open the Check Elements panel by clicking Mesh > Check > Elements > Check Elements from the menu bar.
Verify that you are in the 2-d subpanel.
Identify the elements that have an aspect ratio greater than 5. Aspect ratio is the ratio of the longest edge of an element to its shortest edge. This check helps you to identify sliver elements. All of the hub’s shell elements pass the check; all of the elements have an aspect ratio less than 5.
Identify the tria elements that have an angle of less than 45. This check helps identify sliver elements. All of the hub’s shell elements pass the check; all the elements have angles greater than 20. The surface mesh is suitable for creating a tetra mesh.
Return to the main menu by clicking return.

Step 8 Reflecting the symmetric planes for Suspension Model

Ship work like this
in your own course.