Effect of a tapered metering pin on magnetorheological fluid under an impact load

This study reports on the effects of tapered metering pins on the behavior of magnetorheological (MR) fluid with a magnetic field applied around an orifice under an impact load. We proposed a mechanical model of the MR fluid pipe flow and compared it with the experiment results of the flow under an impact load. We also conducted drop impact tests with four types of tapered metering pins and carried out qualitative analysis of the effects of the pins. The experimental results were analyzed by displacement, velocity and acceleration of the dropping piston. The results show that the shape of the pins has some effect on the entire shock absorption process, whereas magnetic field strength affects the post-peak behavior only, and shock absorption with a longer tapered pin is more widely controllable by a magnetic field. These results indicate that a tapered metering pin has applicability to shock absorption using an MR fluid.