Optimal analysis, design and testing of an electromagnetic damper with resonantshunt circuit for vibration control of a civil structure

Abstract

Control of vibration serviceability problems in civil engineering structures has received considerable attention in recent years. Most of this has been focused on classical technologies such as tuned mass dampers, viscous dampers, viscoelastic dampers and friction pendulum systems, which in many cases are able to provide satisfactory vibration suppression performance. By contrast, electromagnetic actuators and electromagnetic dampers (EMD) have been more extensively used in mechanical applications as a means of attenuating unwanted vibration. In this study, the use of an EMD is investigated for vibration suppression of a civil engineering structure. A voice coil motor is utilised as an EMD in which the terminal ends are connected with a shunt circuit and resonant shunt circuit to improve the damping performance. Therefore, the basic resistor series circuit and resistor, inductor and capacitor (RLC) oscillating circuit are chosen in this application, with both the H∞ and H2 optimisation techniques being used to determine the required shunt circuit components. The resulting electromagnetic shunt damper (EMSD) is experimentally employed for enhancing the damping performance of a five storey aluminium frame structure under random and harmonic excitation. In line with the analysis and design of the damper, it is found that the EMSD experimentally demonstrates good vibration suppression performance.