Seismic response control of a cable-stayed bridge using negative stiffness dampers

摘要

The seismic behavior of a cable-stayed bridge incorporated with negative stiffness dampers (may be activenor semi-active dampers, simulated by pseudo-viscoelastic (P-VE) dampers) between the tower and deck isninvestigated. First, the relationship of bridge damping ratio and connection stiffness between the middlentower and deck is deduced from a simplified cable-stayed bridge model. The maximum damping ratio ofnthe cable-stayed bridge occurs when the optimum connection stiffness is reached. It is found that thenoptimum connection stiffness is composed of two negative values, indicating that the damper stiffnessnshould be taken to be negative. Furthermore, the nonlinear seismic behavior of the cable-stayed bridgenwith P-VE dampers is studied through the numerical simulations. The reduction in the seismic response ofnthe cable-stayed bridge incorporated with the negative stiffness dampers is demonstrated. The influence ofnthe stiffness of P-VE dampers on the seismic behavior of cable-stayed bridges is investigated. The resultsnindicate that the seismic performance of the cable-stayed bridge is the best and the damping ratio of thenbridge achieves its maximum value when the damper stiffness is optimum. The optimum stiffness for thenbridge at nonlinear stage is identical to that at linear phase. Copyright r 2009 John Wiley & Sons, Ltd.