Velocity based semi-active turbo-Lyapunov control algorithms for seismically excited nonlinear smart structures

This paper presents a novel turbo-Lyapunov control strategy for the semi-active control of a nonlinear highway bridge subjected to earthquake ground motions. An optimal control signal has been found to be strongly dependent on the velocity across a magnetorheological (MR) damper. A turbo-Lyapunov control algorithm that utilizes the relationship between absolute velocity of the damper and control signal based on the traditional Lyapunov control algorithm has been developed. In this approach, the control signal is calculated using an integrated traditional Lyapunov function and a turbo-function. This turbo-function adds or subtracts additional voltage depending on the change in the absolute velocity across an MR damper. The performance of the proposed controller has been investigated in reducing response quantities of the highway bridge benchmark model. The results show that the proposed turbo-Lyapunov control strategy is quite competitive with respect to numerous other control approaches in reducing response quantities of the benchmark bridge model.