1 / 10

The effect of load rate, placement angle, and ice type on ice screw failure load

K. Blair, D. Custer Massachusetts Institute of Technology, Center for Sports Innovation, Cambridge, MA, USA S. Alziati, W. Bennett Cambridge University, Cambridge, UK. The effect of load rate, placement angle, and ice type on ice screw failure load. Overview.

iliana
Download Presentation

The effect of load rate, placement angle, and ice type on ice screw failure load

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. K. Blair, D. Custer Massachusetts Institute of Technology, Center for Sports Innovation, Cambridge, MA, USA S. Alziati, W. Bennett Cambridge University, Cambridge, UK The effect of load rate, placement angle, and ice type on ice screw failure load

  2. Overview What is ice climbing, what forces occur during a fall, & why study ice screws? Methods Results Conclusions & Speculation

  3. Ice Climbing & Force on Ice Screw Climber’s gravitational potential is converted to spring energy in the rope during a fall. Expect forces on the order of 3 kN to 12 kN, perhaps as high as 20 kN.

  4. Dearth of data and conflicting data: ice type, strain rate, & screw angle. Word from the wall is “don’t fall.” Ice screws are little changed from the 1980s Climbers Manufacturers Standards Folks Why Bother & Who Cares

  5. Bad ice Good ice (-18ºC) Three angles: –30º, 0º, 30º Pull to failure, two strain rates: 25 mm/s and 0.25 mm/sec Measure force and displacement High speed video record

  6. Big Picture Results

  7. Little Picture Results

  8. Strain rate matters; ice climbers should reduce strain rate. The combined effects of angle, strain rate, and ice type are complicated. Ice in compression is stronger than ice in tension. Temperature matters. Better ice screws can be designed. Ice screw standards deserve another look. Conclusions & Suspicions

  9. Thanks to • Warren & Stef, who did all the hard work • Kim Blair & MIT’s Center for Sports Innovation • The Aero/Astro 16.62x lab folks • Luca for the ice climbing photo

  10. Questions?

More Related