Week - 4 - 2D meshing for Plastic components

AIM

For the given Plastic Bottle Cap model, check for the geometrical errors and take the mid surface by suitable mid surfacing techniques. PID and Thickness assignment has to be done for all the mid surfaces. Mesh the same with the given element Quality criteria. (Refer to the table below for the Quality criteria)

S.No	Quality Criteria	Value
1	Target/Average length	1
2	Minimum Length	0.5
3	Maximum Length	3
4	Aspect	3
5	Warpage	15
6	Skewness	45
7	Jacobian	0.7
8	Minimum Quad Angle	45
9	Maximum Quad Angle	135
10	Minimum Tria Angle	30
11	Maximum Tria Angle	120
10	Tria Percentage	15

OBJECTIVE

Meshing of mid surface of given plastic component with given elemental qualuty criteria

BODY OF CONTENT

• create mid surface of the given component using

faces-->offset

for curved surface use middle option and project it to base and create a new face for mid surfacing

CURVES-->MIDDLE,-->NEW

CURVES-->MIDDLE,-->PROJECT -->NEW

FACES-->MIDDLE

• for teeth area
  • create mid surface of one teeth using face-->middle
  • cons-->project
  • faces-->new
  • create cog 1 and cog2 with different heights points-->on cog
  • transform the created midsurface of the teeth transform-->copy-->rotate
  • enter value for cog1= X, cog2=dx selecting cog, enter number of teeth needed and enter divided angle created by single teeth

angle =360/number of teeth

• for thread
  • take curves-->middle(join curves if needed)
  • cons-->project
  • faces-->new
  • FACES-->EXTENT(JOIN TO BASE )
  • FACES-->INTERSECT(DELETE EXCESS PART FROM INTERSECTING SURFACE)
  • 

• mesh the prepared mid surface
• 
  • input given quality criteria
  • 
  • classic mesh-->mesh generation-->best(for meshing parts)
  • shell mesh-->reconstruct,smooth (for organising the mesh)
  • make sure there is no off elements other than the ones failing for minimum length due to cad geometry
  • reduce formation of trias
    • in perimeter,
    • opposite trias

• after making a proper mesh pattern make note of thickness of different parts and set PID based on their thickness
• take average of thickness on parts having varying thickess throughout and set their PID
• save the file

• Conclusion

  Mid surface of all components has been made and meshing has been done and saved as different pids

  Trias has been kept to minimum to avoid failure due to stress concentration