Theoretical analysis, simulation, and field experiment for vibration mitigation of suspender cables/hangers using the four-wire pendulum tuned mass damper

Suspender cables/hangers occupy a crucial role during the whole service life of suspension bridges/arch bridges/space structures, and their long-term repeated vibration under corrosion and high-stress service state will cause fatigue damage and even induce fatigue failure. To mitigate the vibration of the vertical suspender cables/hangers, a four-wire pendulum tuned mass damper (FWPTMD) is proposed. It mainly consists of the cross bracket, four pendulum ropes, the moving mass, and four universal rotating ball hinges that can rotate in any direction and provide damping. A suspender cable in a real suspension bridge is selected as the research object. First, the design procedure and effect of the modal mass ratio are provided; the optimization design method for parameters of optimal frequency ratio and optimal damping ratio is investigated in detail. Second, simulations are conducted to illustrate its feasibility, and results show excellent vibration mitigation effect. Third, the optimal FWPTMD is designed and fabricated; its performance is further validated by field experiments, and the results are very close to those in simulation. The FWPTMD has the advantages of simple structural form, convenient installation, low cost, easy tuning, easy maintenance, and so forth. Therefore, it can play an obvious vibration mitigation role in the life-cycle of the suspender cable/hanger, and it has a positive meaning to retard fatigue damage, extend the service life, and assure traffic safety under extreme weather.