Week- 5 - Solid meshing

SOLID MESHING - REARVIEW MIRROR

AIM:

• Solid meshing the given Rearview Mirror component using Ansa Preprocessor tool.

OBJECTIVE:

• To mesh the given Rearview Mirror assembly under the given Quality criteria
• Fix the geometrical error while meshing
• Surface Quality after Volume mesh should be good.

2D element Quality criterias

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

3D Tetra element Quality criterias

S.No	Quality Criteria	Value
1	Tet collapse	0.2

PROCEDURE:

• CAD SET UP
  • CAD Geometry
  • Model Clean Up
• CAD MODELING
  • Meshing
• BOUNDRY CONDITIONS SETUP
  • Load Cases
  • Final check for the Quality of elements

PREPERATION OF MODEL FOR MESHING: (Part -1)

IMPORTING THE MODEL TO ANSA

• We can check for the existing PID’s in the ‘Property Card’
• In this model there 4 Properties in total

TOPOLOGY CLEAN UP: (Part - 2)

Steps to be followed in Begining

• After Import the downloaded geometry using File manager, we have give topo to make connectivity of single Cons using (Topo module/Faces group/Topo)
• I prefer work on individual PID's one by one for better handling.

PROPERTIES AFTER GIVEN TOPO

• Then we have to set 'Cons Resolution' for the parent geometry, It is present in (Mesh module/Perimeters Group/Length) for both Macro areas and perimeters length.
• Target length is 1mm, it will be used for achieve the target length while meshing.
• Next step is Orient (Topo module/Faces group/Orient), this Helps to get the same color either Grey or Yellow color one side.

• Now it is time to Geometry Cleanup.
• Before start meshing Geometry Check is necessary, because in Original CAD geometry there might be some errors like Triple cons, Cracked faces etc . . .

• check the geometry for errors or sharp edges or single cons or crack faces using (Checks/Geometry)
• In our 'Rearview Mirror' some errors were present when perform the geomentry check.

• In ANSA there is an option called 'AUTO FIX', i used this function to fix my errors, because it saves more time.

THICKNESS CHECK

• Materials which is having less than or equal to 6mm can be meshed with 2D Meshing.

• This model having more than 6mm, so we can go for 3D Meshing.

STEPS TO FOLLOW BEFORE MESHING

• We have set the Quality criteria and mesh Parameters properly as per the given requirements.
• First select the Mesh Parameters and assign Target length as 1mm, Min length as 0.5mm, Max length as 2mm.
• Set the Quality criteria only Tet collapse for in Solids is 0.2mm

MESH CREATION: (Part - 3)

• After setting up everything in 'Topo Module' we can start meshing in 'Mesh Module'
• Befor that Some areas not Satisfying the minimum length of 0.5mm, in these areas we can suppress the Feature Lines to avoid the errors while meshing, using the option (Topo/Faces/Cut)

STEP 1 - SHELL MESH

• Now we start meshing the properties one by one using (Mesh module/Mesh Generation/Best)

• For the Flat surfaces we can use the Tria in the 'OPTION LIST'

• For the Curved areas we will mesh them with Ortho Tria in 'OPTION LIST'

• We will use the Basic Reconstruction in the (Mesh module/Shell mesh/Reconstruction) for capture the better mesh flow without failing any Elements for required Quality criteria.

STEP 2 - VOLUME MESH

• In volume mesh module, we can use the option (V.mesh/Volume/Define) to define the property which is we are going to Mesh

• Now we can go with the option called (V.Mesh/Unstructured mesh/Tetra Rapid) to perform 3D Tetra mesh for the selected area.

• Solid 3D Mesh has been created, make sure the elements won't fail for any Tet Collapse.

FINAL RESULT:

2D Mesh

3D Mesh

• Here we got the better Result without having any OFF Elements.

REARVIEW MIRROR GOOGLE DRIVE MODEL LINK:

https://drive.google.com/file/d/16sBJhKmOVfLWHwzjoJPCUICTD0FSfCY9/view?usp=sharing

CONCLUSTION:

• Through this challenge Learn about the methods to mesh the materials with Volume mesh
• This model is a easy one, compare to other 2D models, so this one does not take much time to complete it.
• This is the better experience to visually see the technology of the modern world, these Preprocessing softwares are awesome and cool.