Week- 5 - Solid meshing

Aim:

To check the geometry and generate a mesh of the mirror using 2D element quality criteria.

Objective:

S.No	Quality Criteria	Value
1	Target/Average length	1
2	Minimum Length	0.5
3	Maximum Length	2

Use tetra elements to mesh the Volumes defined in the model and check for the below quality after Volume meshing.

S.No	Quality Criteria	Value
1	Tet collapse	0.2

Procedure:

• Importing the model in Ansa hence the model will appear in the graphical area that shown.

• After that, we perform TOPO using the topo option present in the faces section of the TOPO Module the selection process is shown as above.
• Now the topo operation is done and all the free surfaces are stiched with each other and that is shown as below.
• Then perform the orient option is Faces module to modifies the orientation of the faces they are shown as below.
• On opening the CAD geometry into the Ansa database, we provide perimeter length to the whole component for visualization of the curve & edges and also refine the CAD geometry. For this, we go to the Mesh Module and go to the length option present in the section of the perimeter and provide the perimeters length and macros length as 1.

• As the length of perimeter and macros is assigned.
• Now we check for the geometric errors using the check geometry option present in the tools option as shown in the image given below.
• Theses errors can be fixed automatically and also manually. In this model, some errors are fixed by identifying the error and clear that error by untoggled the line and stitch the surfaces again or delete the unwanted surfaces present in that model manually they are shown as below.

2D meshing:

• Now we want to proceed with the model for 2D meshing with some quality criteria that are given by instructor. The component is split into four parts according to the property and proceed for 2D tetra meshing the four different component in the model is shown as below.

• There are some critical quality parameters required for meshing the component that is given in quality criteria.
• Therefore we want to enter all mesh parameters, quality criteria in the mesh parameters, and quality criteria options present in the utilities tab as shown in the images given below.

• In the mesh parameters, we set the min, max, and target element length of the mesh and we provide the mesh type as tria mesh as shown in the fig.
• To enable the total percentage of trias and the quantity of the off elements we are selecting the elements% in presentation parameters. After that select, all details and click apply to obtain the total values of elements and trias percentage of the total model.

Parameters:

• To select Spot Mesh with element type as ortho tria and select the fillet area and do tetra mesh. The selection process is shown as below.

• To select Spot mesh with element type as tria and select the normal surface and do tetra mesh.
• Therefore all the components have meshed separately with the element type as trias and ortho trias.
• After done the meshing as per the quality criteria.
• We need to eliminate all the quality errors caused by using recontruct option present in the shell mesh section of the mesh module we obtain the full meshed model with zero quality errors as shown in the image.

Volume meshing:

• After that we provide the quality criteria of the tetra mesh as shown in the image given below.

• Now as we have define a volume before we proceed for volumetric meshing of the component. we define the volume for the component using the define option present in the volume section of the volume mesh module. A selection process is shown as below.
• Now we want to create the solid property while selecting the define option the property help tab will appear right click on that tab> new > PSOLID and denote the SOLID property.
• Now go to the Volumes> List option and check the define volume.

• To create volume tetra mesh for that component select the unstructured mesh module and click meshing option like tetra rapid, tetra FEM etc. The other way is to right click and select the option called remesh.

• After selecting the tetra rapid volume mesh type then click ok.
• Hence the volume mesh generated shown below.

• Now all the elements tet collaps can be fix using MV free option.
• Now all the elements of the volume mesh is cleared.

Learning outcomes:

• Lerned to mesh the given component using only tria and ortho tria elements.
• Learned to defining a volume and applying volume mesh or tetra mesh over selected volume using Unstructured mesh and clearing errors such as kink, dip and tet collapse elements.

Conclusion:

Therefore the given Rearview Mirror model is checked for the geometrical errors and meshed with elements type as ortho tria and tria as per given quality criteria. After meshing defined the volume and meshed the volume by using an unstructured mesh with the type of Tetra Rapid and Tetra FEM. The off elements also eliminated and the quality criteria are cleared in this model.