Week- 5 - Solid meshing

AIM: For the given Rearview mirror component, check for the geometrical errors and mesh the Surfaces with the given 2D element Quality criteria and create a volume mesh with good surface quality (i.e. There should not and kinks and dips on the surface of the component.)

OBJECTIVE: To check for the geometrical errors for the given component and mesh with the given element Quality criteria. Use tetra elements to model the component and finally create volume mesh for the given component.

QUALITY CRITERIA: To mesh the Surfaces with the given 2D element Quality criteria are given below.

S.No Quality Criteria Value

Target/Average length 1

Minimum Length 0.5

Maximum Length 2

Note: For 2D Elements, Only check for Min length and Max length errors.

* To mesh the Volumes defined in the model and check for the below quality after Volume meshing.

S.No. Quality Criteria Value

Tet collapse 0.2

Note: For 3D Elements, Only check Tet Collapse errors.

PROCEDURE:

First, we want to open it and then import the CAD model by using the File>open option and selecting the rearview mirror. ANSA hence the model will appear in the graphical area

1. After that, we perform TOPO using the topo option present in the Faces section of the TOPO Module.

2. Now the topo operation is done and all the free surfaces are stiched with each other

3. Then perform the orient option in the Faces module to modify the orientation of the faces

4. 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

Therefore the length of perimeter and the macros is assigned

5. Now we check for the geometric errors using the check geometry option present in the tools option

6. In ANSA software there certain kind of tools used for geometry clean up, meshing, and different types of the solver to define certain problems. Initially, the CAD model should import into the software and check for geometry any error found! there are certain types of errors like triple cons, single cons, unchecked faces, convex cons, etc. Here also we obtain these kinds of geometrical errors are observed in this model

7. These errors can fix automatically and also manually. In this model some errors are auto-fixed and the list of errors

2-D MESHING:

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

2.1 = There are some critical quality parameters required for meshing the component that is given in quality criteria

2.2 - Therefore we want to enter all mesh parameters, quality criteria in the mesh parameters, and quality criteria options present in the utility tab

2.3 - In mesh parameters, we set the min, max, and target element length of the mesh and we provide the mesh type as tria mesh

2.4 - 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.

2.5 -To select Spot Mesh with element type as ortho tria and select the fillet area and do tetra mesh.

2.6 - Therefore all the components have meshed separately with the element type as trias and ortho trias.

2.7 - After done the meshing as per the quality criteria

2.8 -We need to eliminate all the quality errors caused by using reconstruct option present in the shell mesh section of the mesh module We obtain the fully meshed model with zero quality errors

VOLUME MESH:

3.1 After, that we provide the quality criteria for the tetra mesh Now we have to 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 volumes section of the volume mesh module

3.2 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 soled property the selection .

3.3 - - Now go to the Volumes>list option and check the defined volume

3.4 - After that select tetra rapid volume mesh type then clicks ok to obtain the volume mesh for that component.

3.5 - Hence the Volume mesh is created for that component but off elements are shown in the volume mesh that represents the tet collapse that has appeared in that model so we want to clear the quality criteria for volume tetra mesh. The obtained volume tetra mesh with off elements

LEARNING OUTCOMES;

Learned to mesh the given component using only tria and ortho tria elements. Learned to defining a volume and apply volume mesh or tetra mesh over selected volume using Unstructured mesh (Tetra Rapid & Tetra FEM) and clearing errors such as kink, dip, and tet collapse elements

CONCLUSION:

Therefore a given Rearview Mirror model is checked for the geometrical errors and meshed with element type as ortho tria & 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 & Tetra FEM. The off elements also eliminated and the quality criteria are cleared in this model.