Optimal design of a tuned viscous mass damper enhanced outrigger system

Abstract. A damped outrigger system is presented to improve the seismic performance of the conventional outrigger system by incorporating a tuned viscous mass damper (TVMD) between the core tube and the perimeter columns. An optimal framework of the design parameters of the TVMD is developed, which includes mode superposition technique and fixed-point method. A simplified cantilever beam with distributed parameters represents the deformation characteristic of the core tube in the outrigger system. Mode superposition decouples the continuous system using a general single-degree-of-freedom system. Then, the fixed-point method is proposed to determine the optimal design parameters of the TVMD by minimizing the H_2- norm of the frequency response function of the displacement response of the outrigger system. A numerical study demonstrates that the designed TVMD effectively mitigates the roof displacement.