Development of large capacity semi-active vibration control device using magneto-rheological fluid

In recent years, there has been increasing research in several industrial fields for development of semi-active vibration control devices. In particular, devices using magneto-rheological (MR) fluids have been attracting great research interest because they can realize high performance as variable capacity dampers. MR fluids are controllable fluids that respond to applied magnetic fields. Applied magnetic fields drastically change the viscosity of MR fluids from an oily state to a semi-solid state. This paper deals with a study on a development of a large capacity device using an MR fluid, i.e., an MR damper. This developed MR damper provides a maximum damping force of 300 kN. Various tests were carried out and the dynamic characteristics, displacement-force hysteresis loops and controllable forces, were investigated. These tests verified that the MR damper provides a technology that enables effective semi-active control of large-scale structure systems, i.e. real buildings and civil engineering structures.