Week 12:Project 2-Meshing of Rear Wheel Holder challenge

Objective:

To extract the midsurface of the given component and mesh the surface satisfying the given quality criteria.

Quality Criteria:

Target Element Length = 5 Units

S.N	Quality Criteria	Value
1	Aspect Ratio	5
2	Skewness	45
3	Warping	15
4	Taper	0.5
5	Min. Length	2 Units
6	Max. Length	8 Units
7	Min angle Quad	45
8	Max angle Quad	135
9	Min angle Tria	20
10	Max angle Tria	120
10	Tria %	10

Procedure:

GEOMETRY CLEANUP & MIDSURFACE EXTRACTION

• The component is imported to Hypermesh using the Import Geometry option.
• After importing the part we delete the solids if any. 
• Any free edges present are rectified using the toggle edge and the surface options.
• To check whether the auto midsurface option can be used, the thickness of the part is checked.
• To measure the thickness, points are added using the add/remove points option in the quick edit panel (F11 key).
• The added points are then projected onto the opposite planes using the project option (SHIFT+F7).
• Then the distance between the points is measured using the distance option (two points) (F4 key).
  

• The measured thickness was a uniform 0.75 units, therefore auto midsurface can be used.
• Before extracting the midsurface in the extraction options of the midsurface panel, the offset+planes+sweeps option is chosen. Then in the auto extraction option, the surfaces are chosen and the midsurface is extracted.
• Once the midsurface is generated all the surface imperfections like free edges, overlapping surfaces are rectified.
• To remove the free edges the toggle edges are used. If there are feature holes in the midsurface the washer split is added to get a proper mesh flow and to avoid trias attached to the free edges.
  

• If there is a missing surface, the Ruled or the spline/filler option (shown in the images below respectively) in the surface panel is used to create a new surface. 
  
  
  
  
  

• Features that are too small to capture without causing the elements to fail are removed using the toggle option or the replace points option.
• The small circular surface that can't be captured is deleted and the filler surf option is used to create the surface.
• The toggle option is used to remove unnecessary cuts in the surface.

MESHING

• The automesh (F12 key) option is used to mesh the component. The surface is divided into small manageable regions so that we can have better control over the mesh flow.
• The given quality criteria are entered into the criteria file settings and the element color mode is set to By Element Quality.
  

• To remove the tria elements the mesh can be remeshed, the cleanup tools in the qualityindex can also be used.
• The drag tria elements option is used to remove tria elements, shown in the image below.
  

• The translate option is used to remove the warpage failure of elements.
  
• The distance option (F4 key) is used to eliminate the maximum and minimum length failure in elements.
  

• The Edges tool (SHIFT+F3) is used to find free edges in the elements.
  
  
  
• These free edges can be rectified using the equivalence option and the nodes of the free edges within the given tolerance range will be joined.
• Using the equivalence option does not attach all the nodes some nodes have to be manually attached using the replace node option (F3 key).
  

ASSIGNING THICKNESS

• Thickness is assigned to the elements through a property. The card image is selected as P1_SHELL and the thickness value is entered in the thickness field.
• This property is then assigned to the component.

FINAL IMAGES

RESULT:

Midsurface was extracted for the given component and it was meshed with the elements satisfying the given quality criteria and thickness was assigned to the elements,