Reduced order modeling and vibration control methods for flexible structures arranged in parallel

This paper proposes reduced order modeling and vibration control methods for flexible structures arranged in parallel. Due to the reduction of vibration brought about by strong winds the higher floors of tall buildings equipped with active dynamic absorbers have become popular habitats. The higher a tall building the lower its natural frequency. Since obtaining sufficient force to control the lower frequency vibrations of tall buildings is a difficult task, controlling the vibration of ultra-tall buildings using active dynamic absorbers is nearly impossible. According to the proposed method, a pair of flexible buildings are controlled actively by controlling each other by means of actuators placed between them. Therefore, it is possible to obtain enough control force under the low frequency. In this paper LQ control theory is applied to the design of such a control system. Using two flexible structures with distributed parameters arranged in parallel, the effectiveness of this method is demonstrated theoretically as well as experimentally.