Structural optimal hybrid control strategies employing dynamic dual units: inerter and spring

Abstract

AbstractThe concepts of optimal hybrid control strategies in the time and frequency domains are proposed herein. The time‐domain optimal hybrid control (also called GangGang strategy) consists of two dynamic units, an inerter and a spring, which work with different force mechanisms at different time phases of vibrations. The inerter acts on the structure when the vibration phase is accelerated, whereas the spring works when the structure deviates from its initial position. The combination of the two piecewise working units achieves better performance than their individual full‐time operations. The working time phases of the two units are complementary, covering the entire vibration period. The hysteresis loops of them are also complementary in the quadrant coordinate system. Owing to the piecewise properties of the two units, the equivalent linearization system (ELS) of such systems is formulated, and a statistical linearization procedure is developed to obtain the equivalent linearization parameters. Then, a parametric study on the equivalent damping is performed through sensitivity analysis and a comparative analysis of the ELS was performed in terms of the standard deviation and peak displacement levels under stationary stochastic excitations. The frequency‐domain optimal hybrid control conforms with the concept of intelligent isolation. The inerter and spring units can be switched according to the excitation frequency by an on–off control benefitting structures subjected to excitations with definite frequency range.