Bridge-Cable Vibration Control By Using Superelastic Nitinol Damper

This paper evaluates the feasibility of superelastic Nitinol damper on bridge cable vibration controlling by both simulation and experiment.  The concept of Nitinol wire superelastic damping is introduced first.  Based on Hamilton principle and Galerkin method, the vibration formulas for a bridge cable superelastic damper system is established.  The computational methods are adopted to achieve the dynamic responses of the systems at both with the damper and without damper.  For the numerical simulation, a practical bridge cable is set-up on a scaled and vibration controlling experiments are carried out under the conditions of free and forced vibration.  The simulation results indicate that the superelastic Nitinol damper can significantly shorten the free vibration decay time of the cable and contribute the equivalent damping ratios of the cable with reasonable parameters and positioning of damper, at the same time to decrease apparently the displacement response amplitude when cable is at white noise excitations.  The experimental results show that the superelastic damper can reduce the acceleration response of the cable under free vibration and forced vibration induced by the deck motion.  Such superelastic damper is promising in reducing the bridge cable vibration and yield mitigating of the bridge.