High-Speed impact experiment for evaluation of magnetorheological fluid’s shock-absorption performance

¹ Ritsumeikan University, Department of Mechanical Engineering, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
² Ritsumeikan University, Department of Advanced Mechanical Engineering and Robotics, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan

^* Corresponding author: keikow@fc.ritsumei.ac.jp

Published online: 7 September 2018

Abstract

Magnetorheological (MR) fluids are categorized as smart fluids, which are made of small iron particles suspended in carrier fluids such as silicone oil. The presence of a magnetic field will instantaneously increase the viscosity of the MR fluid, also known as the MR effect. The application of the MR fluid as viscous dampers to automobiles and buildings has shown excellent performance in shock absorption. To expand the practical application of the MR fluid, various evaluations of shock-absorption performance under high-loading conditions are needed. Therefore, we decided to investigate its performance in high-speed impact conditions. Impact experiments were conducted in different liquids—tap water, two types of silicone oils with different kinematic viscosities, and an MR fluid—and it was investigated how the properties of each liquid affect the shock-absorption performance. Accordingly, it was found that kinematic viscosity and compressibility affect shock-absorption performance. The kinematic viscosity did not affect the speed attenuation of the projectile. Furthermore, it was found that the compressibility affected the pressure wave generated by the entry of a projectile into the liquid.