Week 8-Challenge

OBJECTIVE:

1.To Create tetramesh for the housing model with the following quality criteria:

Minimum Size:2mm

Maximum Size:7mm

Target element size: 5mm

2.To create 3d tetramesh with 6mm element size for model 2 using quick tetra mesh method from the Utility panel for model2

3.To create 3d tetramesh with 6mm element size for model3 using the volume tetra mesh panel for model3

Procedure:

• Model 1:Creating the Tetramesh using the Tetra mesh Panel from 2-d tria elements

1. Importing the geometry:

The geometry is imported from the import panel. The step file is taken from the respective file path

fig1. Importing the geometry

2. Geometric clean up:

The surfaces which are less than the minimum prescribed elemental length should be defeatured or cleaned up as the elements would fail for the minimum size on such surfaces.

In order to check the dimension of the surface,the distance between two points is measured using the distance tool from the geometric panel.

fig2. Surface where the dimension is less than the minimum element size

3. 2d meshing using the trias elements for the given quality criteria:

The Surfaces are meshed with the tria elements wtih the target element size being "5mm"

fig3. Surface where the dimension is less than the minimum element size

fig4. Surface after being modelled with Trias

4.Elemental Clean up using the given quality criteria:

The Elements that are failing the quality criteria are identified and cleaned up uisng the quality index as shown in the figure below

fig4. Element Quality Cleanup using quality Index

For those elements which couldn't be cleaned up using the Quality index,Such elements are identified Using the Check Elements tool from the Tools panel(f10) and saved

fig5.quality check using element check

The saved elements are retrived and masked and then reversed all to retrieve only the failed elements and mask the other elements

fig6.masking the unfailed elements and retainig the failed elements

These elements are remeshed and and cleaned up again & again till the no of failed elements for minimum and maxmum length are non existent

5.Creating the 3d tetra mesh from the tetramesh panel:

The 3d tetramesh are created from the tetramesh tool in the 3d tools

fig7.Creating tetramesh panel from trias

fig8. Creating the 3d mesh from the Tetramesh in 3d tools panel

6.Identifying the 3d elements failing for tet collapse and masking other elements:

The elements failing for the tet collapse are identified using the check elements options in the Tools panel

fig9. The Elements failing for Tet collapse Quality Criteria

The elements that fail for tet collapse are saved and retrieved for masking.The reverse all button is hit to isolate the elements failing for tet collapse

fig10. Elements failing for Tet collapse Being Isolated

7.Clean up of the elemets failing for Tet Collapse:

The tetramesh parameters are set for the given quality criteria .i.e ,Tet Collapse =0.15 in the tetramesh panel of the 3d tool bar

fig11. Tetramesh parameters being set

The adjacent elements are unmasked before carrying out the remeshing

fig12. Unmasking the elements adjacent to the failed elements

The elements displayed are then remeshed to rectify the elements failing for Tet Collapse

fig13. Tetra remesh for the elements to rectify the elements failing for tet collapse

All the elements are remeshed again till all the elements failing for tet collapse are rectified

• Model 2 : Creating 3d tetramesh with 6mm element size for model 2 using quick tetra mesh method from the Utility panel

1. Importing the model:

The model is imported from the import option in the tool bar

fig1. Importing the model 2

2.Geometric clean up :

The Imported model contains certain free edges which needs to be toggled

fig2 Toggling of the free Edges

fig 3 Toggled edge

3. Creating the tetramesh from the Quick tetramesh in the Utillity panel :

• Making the Utility panel Visible

Go to View in the menu bar and then to browsers and then to Hypermesh to tick the Utility option to make the utility panel visible

fig3. Making the Utility panel Visible

fig4.Selecting the Quick tetramesh option in the utility panel

fig5.meshing the component with 6mm trias.png

fig 6 Model meshed with tria of 6mm Using Quick tetra mesh

4.Clean up of the elemets failing for Tet Collapse:

• Identifying the Elements failing for tet collapse and Saving them:

The Elements failing for tet collapse are identified using the Check Elements Options in the tools panel and setting the paramenters for tet collase at 0.15

Fig 7. Quality check for tet collapse and saving the failed elements

• Isolating the Elements failing for tet Collapse and Remeshing them to Clean up the Elements failing for Tet Collapse:

The saved elements are retrieved and masked. The reverse all option is hit to isolate the failed elements hiding all the other elements.

Fig 8 . Isolating the the elements failing for Tet Collapse

• Remeshing the Failed elements with adjacent unmasked Elements to meet the parameters set for tet collapse:

The tetra mesh parameters such as tet collapse are set at 0.15 for tetra remeshing

Fig 9. Setting the tetra mesh parameters for tetra remesh

Fig 10. Remeshing the failed elements with adjacent elements

The Quality check through the check elements tool in the Tools panel actually shows o elements failing for tet collapse.

Fig 11. Elimination of the elements failing for tet collapse

Model 3:Creating 3d tetramesh with 6mm element size for model3 using the volume tetra mesh panel :

1. Importing the Geometry:

The Geometry is imported from import panel

fig 1.3-d model

2.Creating the tetramesh from the Volume tetra mesh panel

Only one half of the solid is made visible and used for meshing as the other half is similar and the perfected esh can be reflected later on for the other half of the solid

The volume tetra-mesh in the tetramesh tool in the 3-d tools panel is used for creating the 3-d mesh

Fig 2.3d teramesh created after Volume tetramesh

3.Identifying the elements failing for Tet Collapse through Check elements options

The elements failing for Tet-Collapse are identified using the 3-d options in the Check Elements option and the failing elements are saved for isolating by unmasking the non failed elements

Fig 3.Saving the elements failing for Tet Collapse

Fig 4.Masking all the elements except the failed elements

The nodes of the elements failing for Tet Collapse are translated so that they no longer fail for the Tet Collapse.

Fig 5.Translating the Nodes with shortest height in the Elements failing for Tet Collapse

This process is repeated till all the elements failing for the tet collapse are corrected and there are no elements left which fail for the Tet Collapse.

Conclusions:

1.Model 1: All the elements were found to be meeting the minimum and maximum quality criteria specified i.e. 2mm and 7mm respectively and no elements were failing for the Tet Collapse.

Final Housing model 1

2.Model 2: No elements were failing for the Tet Collapse value of 0.15

FINAL CRANK HOUSING MODEL 2

3.Model 3: No elements were found to be failing for the Tet Collapse value of 0.15

CHASSIS ASSEMBLY FINAL MODEL 3