In this paper, acoustic radiation response of thin-walled box with particle dampers is predicted. First, the effect of the collisions and friction between the granular inter-particles is interpreted as an equivalent nonlinear viscous damping based on multiphase flow theory of gas-particle. Then the contribution of particle damper is estimated as an equivalent mass-damper system. And the acousti...

A force-feedback control system for VIV experiments is designed and evaluated for the purpose of achieving high accuracy free vibration tests. Through an organized approach, this work details specific methods for minimizing the combined effect of mass and damping using control system fundamentals. The dynamics of the closed-loop system are analyzed, a numerical model constructed and a control s...

In this paper we consider a plate equation with internal feedback and viscoelastic damping localized on a part of the boundary. Without imposing restrictive assumptions on the time-dependent frictional damping, we establish an explicit and general decay rate result that allows a wider class of relaxation functions and generalizes previous results existing in the literature.

We consider the impulsive excitation of fast vertical kink standing waves in a solar coronal loop that is embedded in a potential arcade. The two-dimensional numerical model we implement includes the effects of field line curvature and nonlinearity on the excitation and damping of standing fast magnetosonic waves. The results of the numerical simulations reveal wave signatures which are charact...

A new explicit time integration scheme is presented for the solution of wave propagation problems. The method is designed to have small solution errors in the frequency range that can spatially be represented and to cut out high spurious frequencies. The proposed explicit scheme is second-order accurate for systems with and without damping, even when used with a non-diagonal damping matrix. The...

It is widely accepted that, on ensemble average, the transmission T of guided modes decays exponentially with the waveguide length L due to small imperfections, leading to the important figure of merit defined as the attenuation-rate coefficient α=-⟨ln(T)⟩/L. In this Letter, we evidence that the exponential-damping law is not valid in general for periodic monomode waveguides, especially as the ...

The excitation of propagating surface plasmons SPs on a silver-silica interface by an array of ellipsoidal silver nanoparticles is investigated using numerical simulations as a function of particle volume for three different nanoparticle aspect ratios with representative resonance frequencies. We find that while the SP amplitude depends sensitively on particle volume for each selected aspect ra...

In this paper we consider an inverse problem for a damped vibration system from the noisy measured eigendata, where the mass, damping, and stiffness matrices are all symmetric positive definite matrices with the mass matrix being diagonal and the damping and stiffness matrices tridiagonal. To take into consideration the noise in the data, the problem is formulated as a convex optimization probl...

Eigenmode projection has been used in analysis of the two-dimensional numerical solution of electron temperature gradient ETG turbulence. The secondary Kelvin–Helmholtz instability KHI that breaks up the primary ETG structure at the onset of saturation is found to be associated with strong excitation of damped eigenmodes and strong energy damping. While the KHI structure induces some fine scale...

In this paper, dynamic analyses and field measurements of a tied arch railway bridge is presented. Excessive vibrations of the hangers were obtained, caused by resonance during train passages. The resulting increase of the stress level and number of stress cycles were shown to decrease the fatigue service life significantly. The most critical section is a threaded turnbuckle connection of the h...