Studies on the Mechanisms of Rubber Friction on Roads Covered with Snow and Ice

Research Project

Project/Area Number	62550648
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	高分子物性
Research Institution	Kanazawa University
Principal Investigator	UCHIYAMA Yoshitaka Faculty of Technology, Kanazawa University; Professor, 工学部, 教授 (20019748)
Project Period (FY)	1987 – 1988
Project Status	Completed (Fiscal Year 1988)
Budget Amount *help	¥1,800,000 (Direct Cost: ¥1,800,000) Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000) Fiscal Year 1987: ¥1,400,000 (Direct Cost: ¥1,400,000)
Keywords	Rubber friction on ice / Tribology of ice / Friction coefficient / Temperature adaptable studded snow tire / Studless tire / Contact pressure / Shear strength / ゴム材質 / ゴムの氷上摩擦 / 摩擦速度 / トライボロジー / ゴムの硬さと摩擦 / 氷のトライボロジ
Research Abstract	The friction coefficient of rubber on ice is very low around 0 C. Tt is important problems for motorcars. To increase the friction coefficient aroud 0 C, studded tires utilizing the ploughing term of the friction have used. These studded tires damage road surfaces. Therefore it is desirable to reduce the road damage. A temperature adaptable studded snow tire has been developed and the frictional properties were examined on dry concrete surfaces and ice surfaces. A sheet of a temperature adaptable rubber was attached to the base of a spike pin. The operating force of the stud below 0 C is larger than that above 0 C. When used the temperature adaptable studded snow tire, the demage of road surface is minimized. Recently production of studded tire is going to forbit in Japan. Studies on the rubber friction on ice are important as a fundamental research. When rubbers were rubbed against ice, the effects of temperature, silding speed and base polymer were examined. The results obtained were as follows: (1) The effects of temperature and contact pressure on the friction coefficient of rubber on ice. The friction coefficients of rubber specimens were high at -20 C and -15 C. At -10 C the friction coefficients drastically decreased and they showed low values about 0.2 at the temperature range from -5 C to 0 C. The coefficient of friction decreased with increasing the contact pressure. The friction coefficient of a natural rubber vulcanizate under 0.8 MPA was half value compared to that under 0.2 MPA. (2) The influence of base polymer on the friction coefficient of rubber on ice. Natural rubber showed two times high friction coefficient at the temperature from -20 C to -15 C compared to butadiene rubber. However the difference of the two rubbers were not distinguished at the temperature range from -5 C to 0 C and they showed low value. The difference of the coefficient seems to be originated from the difference of their shear strengths at the contact area.