Controlling Dynamic Response of Structures Using Hybrid Passive Energy Dissipation Device

This paper presents a new hybrid passive control device, consisting of a viscoelastic and a friction damper connected in parallel, to mitigate the effects of wind and seismic events. The two components are synergized with the aid of a novel locking mechanism, which enables the action of one or both the components depending upon the device deformation. This provides an innovative two-phase energy dissipation capacity, and exploiting the individual strengths of the two dampers together. The response of a single degree of freedom (SDOF) hybrid damped system is represented in terms of a linear system using equivalent linearization technique, which includes all associated parameters such as the added stiffness, the added damping and the locking mechanism. In order to ascertain the influence of various parameters of the hybrid device, normalized force and normalized displacement are defined in terms of linear SDOF hybrid damped system and further used to obtain force reduction factor for multi degree freedom (MDOF) system with hybrid device. The proposed design methodology of controlling the structural response using the hybrid device is then applied on a six-story reinforced concrete (RC) building. The response of the conventional moment resisting frame (MRF) system and moment resisting frame system with hybrid device (MRHDF) are compared using the nonlinear time history analysis. The performance of the MRHDF system is found to be superior than the MRF system. The hybrid device can effectively reduce the dynamic response of the building, especially in terms of inter story drift, residual drift, base shear and floor acceleration. In addition the proposed design methodology is very simple as compared to the response modification factor approach. This configuration of hybrid device shows improved performance for meeting multiple objectives under wind/seismic events of real-life structures.