Application of Gyro-Mass Dampers to Mitigate the Seismic Failure in Soft First Story Buildings

Several studies have shown the vulnerability of buildings to sudden changes in lateral stiffness and strength, as in the case of a soft-story mechanism, which can cause damage or even collapse during strong earthquakes. This paper investigates the possibility of improving the seismic performance of soft-story structures by incorporating gyro-mass dampers (GMDs) as a novel alternative solution. GMDs are newly developed passive control devices. They generate a force that is proportional to the relative acceleration applied at their end nodes. The introduction of GMD elements increases the lateral capacity of the first story and the fundamental period of the entire structure. It also reduces the input energy of the earthquake ground motion. To evaluate the effectiveness of these devices, different configurations are proposed and time history analyses are performed.