Hysteretic tuned mass damper with bumpers for seismic protection: Modeling, identification, and shaking table tests

A nonlinear tuned mass damper (TMD) is proposed for seismic retrofitting of buildings. The TMD consists of steel wire ropes that, on one end, are fixed to an oscillating mass, on the other end, they are connected to the main structure by means of a special clamping system based on a double sliding mechanism. The device is equipped with bumpers that provide an additional source of energy dissipation. Experimental dynamic tests aimed to investigate the TMD nonlinear response are discussed. The experimental results unfolding a peculiar pinched hysteretic behavior with almost zero stiffness around the origin are accurately simulated according to a novel phenomenological model. Several shaking table tests are conducted on a laboratory-scale building prototype equipped with the proposed device on the top floor. A comparison between experimental results from shaking table tests and those obtained from numerical simulations is documented to demonstrate the robustness of the proposed nonlinear TMD performance and the accuracy of the numerical model driving its optimization. A critical analysis is also performed taking into account experimental results available in the literature based on shaking table tests conducted on different vibration control devices.