Optimal design of Nonlinear Energy Sinks for SDOF structures subjected to white noise base excitations

Abstract

Nonlinear Energy Sinks (NESs) have recently received increasing attention from researchers because of their capability to passively absorb a significant amount of energy over a wide range of frequencies. In most studies, the dynamic response of the main structure coupled with one or more NESs is analysed for impulsive loading. In this paper, the performance of the NES attached to a Single Degree of Freedom (SDOF) system, under random Gaussian white noise base excitations, is investigated through several numerical simulations. In order to determine the optimal configuration for the device, four different objective functions are considered. Sensitivity analyses with respect to the intensity of the random loads, the mass ratio and the main parameters of the primary structure are presented. The authors propose an approximate design approach based on the use of the Statistical Linearization Technique, and an accurate empirical formulation linking the NES optimal parameters to the characteristic of the main structure and the random excitation. Numerical results are validated by Monte Carlo simulations. Finally, a numerical application for a 2-DOFs system equipped with a NES has been presented in order to investigate the applicability of the proposed empirical approach for Multi Degrees of Freedom structures.

Seismic effectiveness and robustness of tuned mass dampers versus nonlinear energy sinks in a lifecycle cost perspective

“…For the TMD, r and ζ are classically defined. For the NES, ξ is defined like ζ, except that ω 10 replaces ω a (inexistent for a NES), and ρ is defined so that its optimal value would be nearly independent from ω 10 if the seismic input were a zero-mean stationary Gaussian white noise process (Oliva et al 2017).…”

“…No seismic action is considered and no comparison with TMDs is reported. In Oliva et al (2017) a NES is numerically tested on a SDOF structure under white noise base excitation. An approximate optimization based on statistical linearization is proposed, resulting in design formulas providing NES's optimal parameters as a function of the input intensity.…”

Tuned tandem mass dampers-inerters with broadband high effectiveness for structures under white noise base excitations

“…Hence, the broadband random ground acceleration may be considered as a Gaussian zero mean white noise signal within acceptable error range. Employing this model, random vibration analysis of structures with and without control devices is greatly simplified, thus still used today (e.g., Schmelzer et al, Oliva et al, and Kim and Lee). The aim of the present work is to investigate and demonstrate the performance of the TTMDI by extensive simulation results in the frequency domain.…”

An Efficient Stochastic Linearisation Procedure for the Seismic Optimal Design of Passive Control Devices

“…In fact, the probabilistic optimal design of non-linear passive control devices should be performed by means of Monte Carlo simulations, involving a very large computational effort (Oliva et al, 2017). On the other hand, in case of linear systems, the tools of random vibration theory allow for a full probabilistic characterization of the structural response, provided that a reliable stochastic model of the seismic input is available.…”