Week 3

Objective: Removing geometrical errors and meshing the hood with the given element Quality criteria.

fig1 Quality criteria

Step 1:Classify hood into its respective components and give appropriate name to each in property manager.

1. Outer Panel

2. Inner Panel

3. Hinge Reinforcement 1

4. Hinge Reinforcement 2

5. Latch Reinforcement

fig2 Property Manager

Step2: View individual components and check for geometry errors using checks geometry option and simultaneously fix any geometry issues using Auto Fix option.

Clear the geometrical errors by fix option.

fig3 Checks Geometry Manager

Step3: Extracting the midsurface.

Midsurface is extracted using Automid skin option.

Since hood is a sheet metal component having uniform thickness less than 6mm we will use shell meshing technique. In order to use shell meshing technique we need a mid surface.

Fig.4 Automid skin

Do the same for all the individual components in the hood.

Note: Make sure that midsurface extracted has grey color outside .this can be achieved using orient option.

Step4: Assigning PIDs to the extracted midsurface.

Once the midsurface is extracted Property ID has to be assigned with appropriate name, thickness.

Fig.5 Assigning new PID to midsurface

Step 5: Set the mesh parameters with appropriate target length also give the desired quality parameters.

Fig.6 Mesh Parameter option

Fig7 Setting desired quality criteria

Step 6: Defeaturing and geometry simplification.

Defeaturing: Compromising on one feature in order to presrve the another feature.

Removal of unwanted construction lines using cut option so that geometry is simplified.

Fig.8 (Before and after)defeaturing and geometry simplification

Step7: Mesh generation.

Mesh is generated using the best option

Best mesh generation: It is a hybrid method consisting of trias and/or quads based upon dimensions of the model.

Fig.9 Mesh generation using best option

Note: Generated mesh should have a good mesh flow without any waviness or patterns.

Step8: Mesh Improvement.

In mesh generation avoid the following:

1. Opposite trias

fig10 Opposite trias

2. Trias on the perimeter and boundaries.

3. Tria concentration in a particular area

4. Formation of rotating quads

Fig11 unsuitable mesh

These can be achieved by split, swap, join and paste grids option.

Result: Mesh is generated fulfilling all the quality criteria.

Fig12 Final result with 0.82% tria concentration

Learnings:

• Geometry cleanup
• Midsurface extraction
• Defeaturing and geometry improvement
• Mesh generation
• Fixing quality issues

DRIVE Link: https://drive.google.com/open?id=17vld9J_SmttXPcwjtPzbuJgNm3XIYFVa