Week 5

3D Meshing of a rear-view mirror using ANSA.

Objective:

To clear the geometrical errors and perform 3D mesh using tetra elements for the given component by satisfying the given element quality criteria using ANSA.

S. No	Quality Criteria	Value
1	Target Length	1
2	Minimum Length	0.5
3	Maximum Length	2
4	Tet collapse	0.2

Introduction:

Rear view mirror is a device that helps the driver to see rearward. It is one of the most basic but essential safety devices in the vehicle. It provides assistance to the driver during overtaking, parking etc. An anchor holds the rear-view mirror to the windscreen with a special type of joint called ‘swivel’ joint. It allows the driver to adjust the mirror according to his/her seating position.

The model provided is rear view mirror of vehicle is as shown in fig.1. The thickness of the component is more than 6 mm; hence it is modelled using 3D mesh by satisfying the given quality criteria.

Fig.1. Rear view mirror.

Geometry cleanup:

The given component is checked for geometrical errors using checks manager. The errors displayed is cleared using auto fix and tools from hot points, cons, faces & surfaces.

Fig.2. Rear view mirror before topo cleanup.

Fig.3. Rear view mirror after topo cleanup.

Meshing:

• The quality criteria & mesh parameters values are entered.
• The perimeter length value assigned is 1 mm.
• Using spot mesh option, the surface of the component is meshed using tria elements.
• Ortho trias are used for curved surface and normal trias are used for flat surface.
• The quality criteria are achieved by using tools like reconstruct, smooth and split options.
• Under volume mesh module, volume of the given component is defined using tool volumes>> Define>> manual option.
• The list option in the volumes is used to perform tetra mesh on the defined volumes choosing either the tetra rapid or tetra FEM method is as shown in fig.4.
• The tet collapse issue is cleared using tool move under grids option and quality is achieved by using tool fix quality under improve option.
• The meshed model of given component is as shown in the following figures.

Fig.4. Rear view mirror volume defined.

Fig.5. Rear view mirror meshed in red bound mode.

Fig.6. Rear view mirror meshed in hidden mode

Learning Outcomes:

• Learnt the usage of various tools of ANSA software.
• Able to fix the geometrical errors for given model.
• Learnt to mesh solid components using tetra mesh.
• Able to mesh the given model by satisfying the quality criteria.

Conclusion:

• The given model is imported to the ANSA software and the geometrical errors are fixed.
• The surface of the component is meshed with the combination of ortho tria and normal tria elements.
• The volume of the component is defined and meshed using tetra rapid elements.
• The quality is achieved as well as kinks and dips are eliminated.