Effect of the visco-elastic properties of thermoplastic polymers on the flexural and rebound behaviours of ski boots for alpine skiing

Abstract

The flexural behaviour and elastic rebound are the main parameters that determine the global performance of a ski boot during skiing. These two parameters are related to the visco-elastic properties of the polymeric materials used. For this reason, the visco-elastic properties of the materials most utilized for the production of ski boots (polyurethanes and polyolefins) have been studied using dynamic mechanical thermal analysis in a temperature range between 230°C and + 50°C. Also, the flexural and rebound behaviours of the boot have also been tested using specially designed test benches. The dynamic mechanical thermal analysis results and the flexural and rebound tests results were compared, and a significant effect of the visco-elastic properties on the flexural and rebound behaviour of ski boots was seen. Therefore, dynamic mechanical thermal analysis can be used in a knowledge-based design process of new ski boots in order to improve on-snow performances.

Precise prediction of launch speed for athletes in the aerials event of freestyle skiing based on deep transfer learning

“…The aerials event of freestyle skiing is a sport that attracts people's attention around the world. The project mainly demonstrates the technique and flexibility of the athletes, and is very consistent with the athletes' own sports characteristics and physical features 1 . Therefore, the aerials event of freestyle skiing has always been an important breakthrough for athletes to win gold in the Winter Olympics.…”

Computational methods for the investigation of ski boots ergonomics

“…The mechanical behaviour of the rigid thermoplastic components of the shells and of the liner (thermoplastic polyurethane Covestro Desmopan 3860 and 3856, respectively) was identified using technical data provided by the manufacturer. These components followed the assumption of linear elastic isotropic behaviour (tensile modulus 500 MPa for Desmopan 3860 and 310 MPa for Desmopan 3856 at 20 °C temperature, while 0.45 Poisson ratio was assumed for both materials), and the properties agreed with those reported elsewhere [67]. Mechanical properties of rigid thermoplastic components were assumed at 20 °C temperature, because the experimentations on the liner soft foam and fabric materials were performed at room temperature, as described in the following.…”

Effect of material elastic properties and surface roughness on grip performances of ski boot soles under wet and icy conditions

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“…Ski-boots producers are currently pushing for the development of new standards that take into account different types of bindings. Since the amount of ski-mountaineering boots produced is less than 5 % of the overall ski boots market (Colonna et al (2013); Nicotra et al (2015)) the interest of ski boot manufacturers and of researchers is mainly focused toward the study of soles for alpine skiing.…”