Direct observation of frictional contacts during high-velocity slip

Research Project

Project/Area Number	16K13877
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Solid earth and planetary physics
Research Institution	Japan Agency for Marine-Earth Science and Technology
Principal Investigator	KUWANO Osamu 国立研究開発法人海洋研究開発機構, 数理科学・先端技術研究分野, 研究員 (30511969)
Project Period (FY)	2016-04-01 – 2018-03-31
Project Status	Completed (Fiscal Year 2017)
Budget Amount *help	¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000) Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000) Fiscal Year 2016: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Keywords	高速摩擦 / 閃光発熱 / 可視化 / 真実接触点 / 摩擦発熱 / 摩擦 / 地震 / 温度計測 / その場観察
Outline of Final Research Achievements	Recent experiments conducted at sub-seismic to seismic sliding velocities (mm/s to ms) show the dramatic weakening in the friction coefficient for a wide variety of rock types due to mechanochemical effects by frictional heating. Consequently, several weakening mechanisms have been proposed depending on the type of rock specimens. Some of them are based on the sample observation and analysis after experiments. Direct observation of frictional contacts during an experiment is indisputable to constrain an elementary process at frictional contacts during slip. We developed experimental system for direct observation of frictional contacts during high velocity sliding experiment. We observed flash lightning at frictional contacts during high-velocity slip. We successfully measured the temperature distribution of microscopic contacts using two-color method.