A control scheme for AMD in the presence of time-delays and SSI effects for tall buildings

The present study addresses the issue of seismic control of active mass damper (AMD) devices in the presence of time-delay for the tall buildings taking into account soil-structure interaction (SSI) effects. Considering the simultaneous effects of the time-delay and SSI, a control scheme of linear quadratic regulator (LQR) controller with a new form of the weighting matrices is proposed. Then, a design procedure based on a particle swarm optimization (PSO) algorithm is proposed to find the optimal weighting matrices of the controller. The numerical studies are conducted on a benchmark tall building. The validity of the proposed LQR controller is demonstrated for the structure subjected to 44 well-known earthquakes. It is concluded that ignoring the SSI and time-delay effects may give an incorrect estimation of the seismic demands of the building. By increasing the soil softness, the structural responses are often increased. Furthermore, it is found that the proposed controller gives a worthy performance in mitigation of maximum top floor displacement for different soil conditions in the presence of time-delays. However, in the presence of long time-delay, a significant increment may achieve for maximum floor acceleration, especially for the soft and medium soils. However, the maximum drifts of the floors remain within the allowed ranges.