Dynamic behaviour of adjacent frame structures connected with visco-elastic dampers

This work investigates the dynamic behavior of two adjacent buildings, modelled as single-degreeof freedom (SDOF) systems, connected through a visco-elastic (VE) damper. The VE damper has two main effects on the dynamic behavior of the system: (i) energy dissipation provided by the viscous component, (ii) energy transfer and coupling between the modes of the two SDOF systems. The relative contribution of the two effects highly depends on the main dynamic properties of the two SDOF systems and on the damping and stiffness properties of the VE damper. To investigate this complex dynamic behavior, the minimal coupled dynamic system composed by two SDOF systems connected by the VE damper is first analyzed according to the theory of complex damping in order to determine its main dynamic properties, namely complex frequencies, modal damping ratios and displacement modal contribution factors. The seismic response is then investigated through a wide parametric study with the aim of evaluating the trends of several response modification factors related to the peak displacement response and damping system effectiveness. Finally, minimum values of the damping reduction factors are determined to assess the maximum effectiveness of the damping system based on the fundamental dynamic properties of the connected buildings. The results can be useful for the preliminary design phase of the damping system and of the two adjacent buildings.