Seismic response control using electromagnetic inertial mass dampers

• Published in: Earthquake engineering & structural dynamics Vol. 43; no. 4; pp. 507 - 527
• Main Authors: Nakamura, Yutaka, Fukukita, Akira, Tamura, Kazuo, Yamazaki, Issei, Matsuoka, Taichi, Hiramoto, Kazuhiko, Sunakoda, Katsuaki
• Format: Journal Article
• Language: English
• Published: Chichester Blackwell Publishing Ltd 10.04.2014; Wiley; Wiley Subscription Services, Inc
• Subjects: Acceleration; ball screw; Dampers; Earth sciences; Earth, ocean, space; Earthquake dampers; earthquake response analysis; Earthquakes, seismology; Electric generators; electromagnetic; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; Flywheels; Inertial; inertial mass; Internal geophysics; response control; Seismic phenomena; Seismic response; shaking table test; variable damping; rotation; earthquake response analysis; earthquakes; vibration; BASIC; shaking table; acceleration; seismic response; shaking table test; electromagnetic; buildings; variable damping; ball screw; earthquake engineering; oscillations; performances; response control; inertial mass
• ISSN: 0098-8847; 1096-9845
• DOI: 10.1002/eqe.2355

SUMMARY This paper presents a new type of electromagnetic damper with rotating inertial mass that has been developed to control the vibrations of structures subjected to earthquakes. The electromagnetic inertial mass damper (EIMD) consists of a ball screw that converts axial oscillation of the rod end into rotational motion of the internal flywheel and an electric generator that is turned by the rotation of the inner rod. The EIMD is able to generate a large inertial force created by the rotating flywheel and a variable damping force developed by the electric generator. Device performance tests of reduced‐scale and full‐scale EIMDs were undertaken to verify the basic characteristics of the damper and the validity of the derived theoretical formulae. Shaking table tests of a three‐story structure with EIMDs and earthquake response analyses of a building with EIMDs were conducted to demonstrate the seismic response control performance of the EIMD. The EIMD is able to reduce story drifts as well as accelerations and surpasses conventional types of dampers in reducing acceleration responses. Copyright © 2013 John Wiley & Sons, Ltd.