Development of New Optimal Passive Non-detuning Mass Dampers

In this paper, derived from a M.Sc. thesis jointly developed at Politecnico di Milano and TU Wien, an innovative design strategy for the well known Tuned Mass Damper (TMD) passive structural control device is presented. Linear TMDs need to stay properly tuned to the principal structure in order to be effective. The newly proposed “NextGenTMD” incarnation aims at overcoming the detuning by implementing a hysteretic version of the TMD, able to remain tuned despite the hysteretic response of the primary structure itself. The usage of Genetic Algorithms introduced in the design process of the NextGenTMD is at the basis of the proposed approach. Within this context, the design phase of the TMD is presented as a multi-objective minimization problem. The proposed design methodology is applied on a reduced numerical model of a four story building, of which full scale seismic pseudo-dynamic test results were available. The calibration of this reduced hysteretic model is carried out as well as a minimization problem exploiting Genetic Algorithms. The capabilities of the NextGenTMD, designed according to the proposed procedure, is assessed with respect to a set of spectrum compatible time histories, according to the Eurocode 8. The very promising results obtained, from numerical simulations, show that the NextGenTMD can be effective in a seismic setting while the simplicity of the installation is promising for its large scale diffusion and, consequently, for a more effective reduction of the seismic vulnerability of the built environment.