No abstract

Auxetic materials offer potential to be applied to sports safety equipment. This work reports quasi-static and impact testing of auxetic open-cell polyurethane foam -fabricated with a compression and heat treatment process -in comparison to its conventional counterpart. The foam was compressed to 70% of its original dimension along each dimension during the conversion process. Quasi-static compression testing confirmed the converted foam to be auxetic, with a Poisson's ratio of -0.08. Impact testing was performed for energies up to 5.6 J with an instrumented drop rig and high-speed video. Peak accelerations were ~3 times lower for the auxetic foams, because they prevented bottoming. This work has shown further potential for auxetic foam to be applied to sports safety devices. Future work should look to optimise foam selection and the conversion process, while comparing auxetic foam with existing materials and products.

No abstract

Surgical treatment of TOF is associated with good results in terms of control of acute symptoms and long-term outcome, particularly concerning oral intake and spontaneous breathing.

Skiing and snowboarding are popular snow-sports with inherent risk of injury. There is potential to reduce the prevalence of injuries by improving and implementing snow-sport safety devices with the application of advanced materials. This chapter investigates the application of auxetic foam to snow-sport safety devices. Composite pads-consisting of foam covered with a semi-rigid shell-were investigated as a simple model of body armour and a large 70 × 355 × 355 mm auxetic foam sample was fabricated as an example crash barrier. The thermo-mechanical conversion process was applied to convert open-cell polyurethane foam to auxetic foam. The composite pad with auxetic foam absorbed around three times more energy than the conventional equivalent under quasi-static compression with a concentrated load, indicating potential for body armour applications. An adapted thermo-mechanical process-utilising through-thickness rods to control in-plane compression-was applied to fabricate the large sample with relatively consistent properties throughout, indicating further potential for fabrication of a full size auxetic crash barrier. Further work will create full size prototypes of snow-sport safety devices with comparative testing against current products.