STRESS AND STRAIN ANALYSIS OF A HOCKEY STICK

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STRESS AND STRAIN ANALYSIS OF A HOCKEY STICK

• Andrew Mills
• Jeff Tibbe
• Brad Vander Veen

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Loading Analysis

• Loading is due to stick blade striking the ice
• In bending and torsion
• The stick bends similar to a bow
• Elastic energy stored in the bent stick is used
  to accelerate the puck

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Picture
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Picture

• The bottom half of the stick looks like a
  cantilever beam this is how the load will be
  modeled

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Model of a Hockey Stick
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Experimental Setup

• Cantilever beam in torsion and bending
• Fixed with clamps at midpoint of shaft
• Mass hung where stick blade would strike the ice
• Strain gage place at fixed end

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Theoretical Principal Strains
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Theoretical Principal Stresses
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Experimental Setup
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Experimental Setup
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Experimental Setup
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Diagram of Rosette
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Results
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Experimental Principal Strains
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Experimental Principal Stress
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Comparison

• Theoretical and Actual follow the same trends.
• Most results had a percent discrepancy of about
  15 to 40
• Torsional stress results did not agree as well as
  bending stress results
• Angles of principal stresses and strains agreed
  (3 vs 5)

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Failure Analysis

• Hockey stick yielded when a 70 lb load was
  applied.
• At 60 lbs, the measured maximum principal stress
  was 49,000 psi
• The yield stress for the material was 52,900 psi
• The 70 lb load caused a principal stress higher
  than the yield stress

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Discussion

• Error in torsional results was higher because it
  was hard to constrain it
• Measurements were very sensitive to slight
  constraint movements

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Conclusion

• Stresses and strains in a theoretical analysis
  agreed well with results found in the actual
  experiment

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Questions?