Estimation of Control Capacity for Squeeze Mode MR Damper with

This paper is focused on developing a Squeeze Mode MR Damper with large control capacity for effective vibration mitigation in infrastructures such as long span bridges and skyscrapers, etc. In order to maximize the magnetic field required for control of MR fluid, this device is designed by separating electromagnet system from the main cylinder for large capability of control force without changing its total length. This developed MR damper is tested to estimate its maximum control capacity and dynamic range(defined as the ratio of the maximum force to the minimum force that MR devices provide), inputting various strength magnet fields. These experimental results make it possible to estimate its maximum control force by drawing a curve showing the relationship between generated forces and applied magnetic fields. In order to verify its performance as a semi-active control device, its dynamic range is calculated. Through all tests, the developed MR is proved to be an effective device for the response control of infrastructures