Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 07, 2017 - October 09, 2017
Magnetorheological (MR) fluids are categorized as smart fluids, which are made of small iron particles suspended in carrier fluids such as silicone oil. A presence of a magnetic field will instantaneously increase the viscosity of the MR fluid, also kwon as the MR effect. The application of the MR fluid for automobiles and buildings for viscous dampers has shown excellent performance for shock absorption. In order to expand practical application of the MR fluid, various evaluations of shock-absorption performance under high-loading conditions are needed. Therefore, we decided to investigate the performance on high-speed impact. As the first step, impact experiments were conducted in transparent liquids—tap water and two kinds of silicone oils with different kinematic viscosity—instead of the MR fluid, and it was investigated whether the kinematic viscosity and the speed of sound (i.e. compressibility) of each liquid affect the shock-absorption performance or not. As the result, it was found that the kinematic viscosity and the speed of sound did not affect the velocity attenuation of the projectile. Furthermore, it was found that the speed of sound affected the pressure of stress wave generated by the entry of projectile into liquid. It is considered that these results are related to the conditions of liquid around the projectile.
