Inerter-based dissipation for vibration control of a cable-stayed bridge subjected to transverse seismic excitation

Cable-stayed bridges are an effective solution for infrastructural connection due to their long-spanning capacity and slenderness. However, in the most common deck-tower floating configuration, such structures are prone to be damaged under strong seismic excitation due to excessive transverse displacement demand and possible pounding between the towers and the deck. This paper addresses the transverse vibration control problem in cable-stayed bridges subjected to seismic excitation by exploiting Inerter-Based Dissipators (IBDs). Specifically, a simplified four degrees-of-freedom dynamic model of a cable-stayed bridge prototype is introduced to describe its transverse response, considering the effect of different configurations of IBDs in the equation of motion. The design of such devices is performed using an optimization approach, the presence of the earthquake is simulated describing the seismic acceleration as a filtered Gaussian stochastic process and the damper nonlinearities are addressed via the Stochastic Linearization Technique. A comparative analysis is carried out for a bridge in terms of transverse displacement control considering a proposed IBD configuration and comparing its performance with other IBDs systems and conventional viscous dampers. It is shown that the proposed IBD configuration achieves a superior transverse vibration control performance compared to the other inerter-based devices considered, regardless of the selected level of inertance or the band-type excitation, with significant tower-deck relative displacement reductions as well as shear force and bending moment at the tower base.