1. Stress Concentration in Snap Ring Grooves
Jon Shelley
Doug Hogge

2. Description of Project

3. 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

4. Method Used to Accomplish Project
Macro File
Results File

5. 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/2+r
!Material Properties
MP, EX, 1, E+06
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,,,

6. Model-Geometry OD (1”- 4”) Ratio (1.02 – 1.1) Height (2”)
Radius (0.005” – 0.015”)
Gap (0.1”)

7. Model-Mesh Refined Original Elements (1,649-10,132) Elements (53-400)
Nodes (5,140 – 31,005)
Mapped and Free Mesh
Original
Elements (53-400)
Nodes (200-1,517)

8. Model-Boundary Conditions
Surface Load
Axisymmetric Element
Symmetry about X-Axis

9. Model Verification Original – (1 hr) Refined – (7 hrs)
Two Models – (0.5% - 1%)
Original vs. Refined – (2% - 11%)

10. FEA Results

11. Stress Concentration Factor

12. DOE Outside Diameter Radius Ratio of Outside to Inside 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

13. DOE Results Stress Increase as Radius Decreases Ratio Increase
OD Increases

14. Stress Concentration Plot

15. Comparison to Actual Values
Error Between Actual and Calculated Values (0.05% %)

16. 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