Enhancing Seismic Performance of Cable-Stayed Bridges using Tuned Mass Dampers

Abstract

Enhancing the seismic performance of cable stayed bridges (CSBs) gained increasing attention over the past few decades. A TMD is a comparatively lightweight component consisting of a mass and springs tuned to oscillate at nearly the same frequency of the structure but with a phase shift. Reduction of vibrations is achieved by transferring some of the structural vibration energy to the TMD and dissipating the energy by the inertia. The aim of this paper is to investigate how TMD could enhance the performance of CSBs. Finite element analysis has been performed to assess the optimum value of TMD mass ratio by comparing the performance of the CSB before and after incorporating the TMD under different excitation records. Results shows that, the presence of TMD leads to a noticeable improvement in different responses. For μ values between 0.25% and 0.5%, the bridge shows the best performance. Also, for μ > 1% the efficiency of using the TMD does not show significant increase that warrant the cost and difficulty of implementation which makes no need to increase the mass of TMD.

Keywords

• cable-stayed bridges
• earthquakes
• tuned mass damper