Nonlinear rotational inertial double-tuned mass damper for reducing human-induced floor vibration with frequency detuning

Abstract

This study proposes a novel nonlinear rotational inertial double-tuned mass damper (NRIDTMD), which introduces a cubic stiffness element into the inerter-based passive control system RIDTMD, by exploiting the frequency insensitivity of nonlinear energy sink to overcome the frequency detuning problem in human-induced floor vibration control. Due to its nonlinear nature, the complexification-averaging technique is adopted to obtain the approximate steady-state response of the coupled floor-NRIDTMD system, and the number of the solutions and stability of the responses are discussed. Based on the genetic simulated annealing algorithm, the design parameters of the proposed NRIDTMD are optimized, and the empirical design formulation and response prediction equation are further proposed. Considering the effect of frequency detuning caused by human-structure interaction, floor stiffness degradation and mass increase, a numerical model of an experimental floor is used to verify the vibration mitigation performance of the proposed NRIDTMD, and compared with those of TMD and RIDTMD. The results reveal that the empirical formulation and prediction equation exhibit excellent accuracy and applicability, and the proposed NRIDTMD can minimize the acceleration response increment of the floor in frequency detuning, exhibiting better frequency robustness than those of conventional linear dampers.