Aim:

To mesh the given inner door panel geometry of a car with the following given quality criteria and assign thickness.

Procedure:

1. Hypermesh is opened in Optistruct solver mode.
2. The given inner door panel geometry is imported in Hyperworks using Import Solver deck
   
   
   

   Figure 1 - Given hood model

3. Midsurface generation

   1. The mid surface for the model is performed using “skin offset” method for extraction. The steps for mid surface extraction is as follows:

      1. Geometry --> Midsurface --> Select extraction option as “skin offset” --> in the auto extraction window, select the surfaces --> Extract
         
         

         Figure 2 - Midsurface

      2. Some surfaces in the geometry were not properly created from the auto mid surface option. Hence, these surfaces were deleted and were extracted again manually as follows:
         1. Make the midsurface component as current by right clicking on the component and selecting “Make Current”
         2. Select Geometry --> Surface edit --> Offset --> select one side of the shell surface (either top or bottom faces) --> Duplicate the surface --> select “current component” --> Enter offset distance --> Create
            
            
4. Assign quality criteria
   1. Select Preferences --> Criteria file settings --> Enter the quality criteria --> Apply --> OK
      
      
      

      Figure 3 - Criteria editor

   2. Select Preferences --> Parameter file settings --> Enter the target element size --> Apply --> OK
      
      

      Figure 4 - Parameter editor

5. Meshing

   1. Select 2D --> Automesh --> Enter element size as 4 --> Mesh type as mixed--> select the surfaces to mesh --> Select mesh
      
      

      Figure 5 - Meshed geometry
      
      

      By left or right clicking on the number on each edge of the model, the number of mesh points can be increased and decreased to achieve better mesh.

   2. Next, it is checked if the mesh generated passes the quality criteria. This is checked in the “quality index” option in 2D Tab. This is done as follows:

      1. The quality parameters entered during autocleanup is present in this option too. By toggling the “fail” option in display threshold, the failed elements are visualized
         
         
         

         Figure 6 - Quality index toolbox

      2. The elements are cleaned up by using one of the options in the cleanup tools. The tools available are
         
         
         

         Figure 7 - Cleanup tools

6. Create property & assign thickness:

   1. Model tab --> Right click --> Create --> Property --> Enter suitable name for the property --> Enter the shell thickness
      
      

      Figure 8 - Creating shell property and thickness

   2. Create component for the mid surface using following steps:

      1. Model tab --> Right click --> Create --> Components --> Enter suitable name for the component

   3. In the Prop_Id section in the component card, the appropriate property is selected and they are linked
      
      

      Figure 9 - Link component and property

7. The final corrected mesh for the component is as follows:
   
   

   Figure 10 - Final mesh for inner door plan
   
   Next, it is checked for quality criteria failures in the qualityindex option.
   
   

   Figure 11 - Check mesh for given quality criteria
   
   The model still has some failed elements which cannot be cleared. Even, if attempted to clear them, they can cause improper feature capturing. Hence, the failed elements were left as such.
   
   

   Figure 12 - Elements that failed quality index
   
   

   Figure 13 - Elements that fail quality index
   
   The model can be toggled to detailed representation by using the 1D & 2D Detailed Element Representation
   
   
   
   

   Figure 15 - Detailed representation view of the mesh model

Learning Outcomes:

1. Auto & Manual Mid surface creation
2. Meshing of components using automesh
3. Correcting the components that fail for the given quality criteria using cleanup tools
4. Assign properties for various surfaces in the model corresponding to its model thickness

Conclusion:

The given inner door panel geometry of a car with the following given quality criteria is meshed and thickness assigned.