Seismic protective devices in the form of isolation and supplemental damping devices can be effective means in mitigating the seismic responses of structures. The required stiffness and damping values to achieve optimal performance depend on the characteristics of structures and ground motions. Instead of using actively controlled devices, one can select the passive devices to roughly mimic the...

This investigation is concerned with application of nonlinear fluid viscous dampers for asymmetric-plan systems. For this purpose, the behavior of nonlinear fluid viscous dampers is summarized first followed by the effects of damper nonlinearity on seismic response of asymmetric systems. It is shown that the peak force in nonlinear damper tends to be smaller compared to linear damper. However, ...

The vibration attenuation mechanism of shear thickening fluid- (STF-) filled sandwich structures was investigated in this study. Structural equivalent damping, stiffness, and mass increased simultaneously with the increase volume fraction fluid. However, damping ratio decreased natural frequency structural mass. Thus, not a monotonically increasing function STF. A modified strain model layer de...

The vertical structure of the low-level atmospheric response to an elevated large-scale, low-frequency heat source in the Tropics is explored using linear tidal theory on an equatorial beta plane. Through the calculation of the projection of a large-scale, low-frequency thermal source onto the meridional eigenfunctions, the contributions from a set of discrete meridional eigenfunctions with pos...

Infrared metamaterial design is a rapidly developing field and there are increasing demands for effective optimization and tuning techniques. One approach to tuning is to alter the material properties of the metals making up the resonant metamaterial to purposefully introduce resonance frequency and bandwidth damping. Damping in the infrared portion of the spectrum is unique for metamaterials b...

A method is presented to determine the bulk elastic properties of isotropic elastic closed-cell foams from impedance tube sound absorption tests. For such foams, a resonant sound absorption is generally observed, where acoustic energy is transformed into mechanical vibration, which in turn is dissipated into heat due to structural damping. This article shows how the bulk Young's modulus, Poisso...

This paper presents a versatile and robust algorithm for the optimal design of adjacent structural systems linked by passive energy dissipation devices. The algorithm works both with stationary and nonstationary force input. It is a two-stage design procedure that (i) determines an active control law, and then (ii) adds damper and stiffness coefficients that are computed based on the minimizati...

In a recent paper by B. G. da Costa {\it et al.} [Phys. Rev. E 102, 062105(2020)], the phenomenological Langevin equation and corresponding Fokker-Planck for an inhomogeneous medium with position-dependent particle mass damping coefficient have been studied. The aim of this comment is to present microscopic derivation such system. It not equivalent that in commented paper.