Nonlinear viscous dampers interconnecting adjacent structures for seismic retrofitting
The effects of a dissipative coupling between adjacent structures subjected to synchronous ground motion have been investigated. The study evidences the existence of an optimal pair of the design parameters characterizing the passive interconnection described by a Kelvin-Voigt model. The assumed optimization criterion corresponds to the tuning method by which the modal damping introduced in a simple 2dofs dynamic model is equalized and maximized. This direct method has been compared with a dissipative coupling design employing a LQR energy-based procedure, followed by an equivalence criterion between the achievable passive and active damping performance. The analysis of the displacement transfer functions with respect to a harmonic ground motion permits to compare the effects of different coupling design with the technical perspective of mitigating the seismic response. Other results relative to dissipative interconnections described by linear and nonlinear Maxwell models are also discussed. The developed approach have been used to drive the seismic retrofitting of the main façade of the Edifice A belonging to the Engineering Faculty buildings of University of L’Aquila, presented as case study.