LAUSR

This paper evaluates a new hybrid passive device that comprises two different passive energy dissipation categories, namely, viscoelastic damper and friction damper. The device operates as a synergic unit using a novel locking mechanism. The hybrid passive device offsets the drawbacks of individual devices and facilitates improving the performance of structures for multiple excitation vibration levels due to wind and seismic events. Both devices are connected in a parallel combination using locking mechanisms and exhibit distinct hysteretic characteristics under small and significant deformation. The viscoelastic damper alone will be activated for extreme winds and minor to moderate earthquakes, and both devices will work simultaneously for strong earthquakes. Considering the advantages of such a new device, this article presents a new seismic design method structures equipped with a hybrid passive dampers device using the energy-balance concept. The method accounts for the structural member's inelastic behaviour, phase transformation of the stiffness and the energy dissipation capacity of the energy devices to achieve the intended performance level under the design earthquake hazard. The proposed method has been applied on a six- and a twelve-storied reinforced concrete building. The seismic performance is verified through nonlinear time history analysis using a set of near and far-field ground motions. Numerical results are investigated in terms of the inter-story drifts, the residual drifts, the floor acceleration and the yield mechanisms. The structure's performance corresponds well with the target performance levels.