Hybrid Mass Damper: A Tutorial Example

This chapter compares three different ways of mitigating the dynamic response of buildings: Dynamic Vibration Absorber (DVA), Active Mass Damper (AMD) and Hybrid Mass Damper (HMD). The methodology is illustrated with a shear frame example subjected to a random seismic input. Two different ways of implementing the HMD are considered, one called passive starting from a mistuned DVA, and one called active starting from a tuned DVA and using a control system with two feedback loops. It is shown that a well designed HMD may produce performances comparable to that of an AMD while significantly reducing the actuator force and stroke requirements. Besides, the active implementation is immune to control system breakdown, because the HMD is reduced to a properly tuned DVA with optimum performances for a passive system.