Energy Analysis of a Damped Substructure Outrigger System

A damped outrigger system (DO) has been proposed to enhance the seismic performance, in which links between outriggers and perimeter columns are artificially disconnected and implemented by dampers. Such an operation essentially destroys the structural integrity and becomes a potential threat for structural safety. Moreover, its performance is very sensitive to the stiffness of perimeter columns. In this study, a mega-sub controlled system is employed to propose a novel outrigger system, i.e., a damped substructure outrigger system (DSO). The novel system has good structural integrity due to its main structure consisting of the core tube, outrigger, and perimeter column. To present further investigation, the govern equations of DSO are derived by the simplified model which is regard as a cantilever beam system with a multirotation spring and energy dissipation substructure. Then, the energy distribution and seismic performance are parametric investigated. Finally, the damping effects of DSO are discussed. The results indicate that DSO possesses the superiority of damping performance. Compared with DO, DSO is less sensitive to perimeter column stiffness. Moreover, the proposed system can obtain the high efficiency in energy dissipation but with less damping cost than that of the viscous damper. Also, the larger stroke of the viscous damper can be found for DSO.