Comparison between rubber-ice and sand-ice friction and the effect of loose snow contamination

摘要

The application of sand particles is a common method to improve the friction of aircraft tires on snow or ice covered runways. Hence, an understanding of the prevailing rubber-ice and sand-ice friction mechanisms is of practical interest. Rubber-ice and sand-ice friction measurements were made with a British Pendulum Tester at temperatures between -22 and 0℃ and the effect of loose snow contamination on top of the ice was investigated. The results (the response of the instrument) were expressed in a sliding length averaged friction coefficient μ_(BP). Close to the melting point the friction of rubber on ice was low and increased with decreasing ice temperature. Below -5℃, reasonably high friction levels (0.2 <μ_(BP)<0.5) were obtained between rubber and ice, but the friction level dropped drastically by the presence of a very thin layer of snow. The sand-ice friction level was less dependent on ice temperature and clearly not as much affected by the presence of snow, compared to rubber-ice friction. The micromechanisms involved in rubber-ice and sand-ice frictions were investigated by the application of etching and replicating technique (ERT) developed for the examinations of the dynamics of dislocations in ice during deformation.