This is a group-based case study which looks at the composition and construction of modern skis. Today’s ski is of a complex design comprising of a variety of materials, enabling great speed and enhancing control.
Background to ski construction
Group allocation (5-6 members)
Independent study and research
Describe the types of materials used in modern skis and explain qualitatively why they have been used.
Understand quantitatively the effect of fibre, matrix and core modulus on the bending stiffness of the ski.
Consider the case of a ski travelling down an icy slope. The ski will not be in contact with the slope at all times. The surface of the ski slope is a mix of densely compacted snow and hard ice, the surface is often very uneven. If the ski is too stiff the skier will become grounded, yet, if the ski is not stiff enough the skier won't be able to ski. How stiff should the ski be?
Identify suitable materials for the base of the ski and explain the selection in terms of material properties.
Describe experimental methods to measure damping in skis and ski materials.
This should be considered both for rectangular test pieces of ski materials and the complete ski. Impact with the ski and the icy slope causes the ski to vibrate and materials with relatively high damping factors are required to reduce this level of vibration. How can this dampening be measured?
Each group must submit a single written report addressing the above tasks and summarising the main findings and conclusions drawn. The report is to be 1500 words long (about 4 pages) not including diagrams. Each group must also give a 10 minute presentation (40% of the case study mark). Ensure you introduce who you are and the main areas of your talk. Finish with a slide showing the main conclusions. Click for tips on presentations and reports.
There are many manufacturers websites with sufficient skis information on skis.
Ashby M and Jones D, (1998) Engineering Materials 2 - An introduction to Microstructures, Processing and Design , Butterworth Heinemann, Oxford.
Callister W Jr. (1997) Materials Science and Engineering - An Introduction, John Wiley & Sons Inc, New York.