Stress Concentration in Snap Ring Grooves

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Stress Concentration in Snap Ring Grooves

• Jon Shelley
• Doug Hogge

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Description of Project
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Description of Project

• Create a Model to Determine Stress in a Snap Ring
  Groove
• Calculate Stress Concentration Factor
• Create Graph Showing Stress Concentration
• Compare Results to Actual Snap Ring Groove
  Dimensions

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Method Used to Accomplish Project
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Model Macro File

• !IMPORT PARAMETERS
• PARRES, CHANGE,ring,exp,
• !Keypoints
• k,1,0,0
• k,2,0,l
• k,3,OD/2,l
• k,4,OD/2,t/2r
• !Material Properties
• MP, EX, 1, 30.00000E06
• MP, NUXY, 1,0.27
• !Mesh Constraints
• LESIZE,8, , ,12,0, , , ,1
• ames,2
• !Boundary Conditions and Loads
• SFL,8,PRES,-FYload,

!Solve Model /SOLU SOLVE !Retrieve
Output nsort,s,y get,syMax,sort,0,max !Save
Output to a File /output,ring,post,, !Exit Macro
File /EXIT,NOSAVE,,,
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Model-Geometry

• OD (1- 4)
• Ratio (1.02 1.1)
• Height (2)

• Radius (0.005 0.015)
• Gap (0.1)

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Model-Mesh

• Refined
• Elements (1,649-10,132)
• Nodes (5,140 31,005)
• Mapped and Free Mesh

• Original
• Elements (53-400)
• Nodes (200-1,517)

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Model-Boundary Conditions

• Surface Load
• Axisymmetric Element
• Symmetry about X-Axis

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Model Verification

• Original (1 hr)
• Refined (7 hrs)

• Two Models (0.5 - 1)
• Original vs. Refined (2 - 11)

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FEA Results
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Stress Concentration Factor
   
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DOE

• Outside Diameter
• 13 Values (1 4)
• Radius
• 4 Values (0.005 0.007 0.01 0.015)
• Ratio of Outside to Inside Diameter
• 9 Values (1.02 1.1)
• Total of 468 Runs

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DOE Results

• Stress Increase as
• Radius Decreases
• Ratio Increase
• OD Increases

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Stress Concentration Plot
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Comparison to Actual Values

• Error Between Actual and Calculated Values (0.05
  - 4.09)

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Conclusion

• Refined model produced less variation but
  increased processor time
• Ansys can be used as a powerful tool for design
  studies
• Model should be compared with actual data
• From our results equations could be found to
  calculate stress concentration in snap ring
  grooves