| The research detailed within this dissertation will investigate innovative smart structures, including the seismic protection of buildings and the mitigation of wind vibrations in cable structures. The focus is on understanding the dynamic characteristics of these smart structures, identifying viable semiactive control strategies, assessing the merits of the control strategies relative to passive and active control alternatives, and demonstrating the structural control concepts. Analytical, numerical and experimental methods are employed in this research.; Coupled building control is shown to be a viable method to protect tall buildings from seismic excitation. Various coupled building configurations are examined and coupled building design guidelines identified. Constraints on the maximum control force are enforced. A semiactive control strategy applied to a coupled building pair provides performance bounded by passive and active control strategies. Active coupled building control, employing acceleration feedback, is experimentally verified.; The semiactive control of cable structures is examined, studying the vibration reduction of long cables. The effect of cable sag, axial stiffness, angle of inclination, and damper location on the control performance is examined. Specific levels of sag, axial stiffness, angle of inclination, and damper location resulting in poor performance are identified. A semiactive control strategy is shown analytically to achieve similar performance to active control, with performance well beyond that achieved with passive control. A semiactive control strategy is verified experimentally on a 12.65 meter cable experiment employing a smart shear mode magnetorheological fluid damper. The experimentally achieved performance levels are explained by including control-structure interaction.; Structural control is shown analytically and experimentally to be a viable method of protecting civil structures from natural hazards, such as seismic and rain-wind induced vibration. Semiactive control strategies, when applied to civil structures, can provide increased performance over passive control without the concerns of energy and stability associated with active control. |
