In this paper we study the null-controllability of a beam equation with hinged ends and structural damping, the damping depending on a positive parameter. We prove that this system is exactly null controllable in arbitrarily small time. This result is proven using a combination of Inghamtype inequalities, adapted for complex frequencies, and exponential decay on various frequency bands. We then...

Energy is dissipated in engineering systems through a variety of different, typically complex, damping mechanisms. While there are several common models with physical interpretations, it often necessary to examine noisy, experimental data order identify and fit the parameters. One class methods fits parameters based on decay envelope signal’s peaks some assumed mechanism. exist results literatu...

In this paper, the periodic, quasi periodic and chaotic responses of rotational machines with a hexagonal centrifugal governor are studied. The external disturbance is assumed as a sinusoid effect. By using the forth order Rung-Kutta numerical integration method, bifurcation diagram, largest Lyapunov exponent and Lyapunov dimension are calculated and presented to detect the critical controlling...

In this paper, the quality factor of thermo-elastic damping in an electro-statically deflected micro-beam resonator has been investigated. The thermo-elastic coupled equations for the deflected micro-beam have been derived using variational and Hamilton principles based on modified couple stress theory and hyperbolic heat conduction model. The thermo-elastic damping has been obtained discretizi...

We analyze the effect of damping (absorption) on critical self-focusing. We identify a threshold value δth for the damping parameter δ such that when δ > δth damping arrests blowup. When δ < δth, the solution blows up at the same asymptotic rate as the undamped nonlinear Schrödinger equation.

It has been observed that even though modal frequencies are well estimated using Operational Modal Analysis (OMA) techniques, damping estimation is not as accurate. The opinions on this aspect of OMA have been widely varying and no consensus or definite answers are available. In this paper the OMA procedure, data processing and modal parameter estimation, is studied with respect to proper dampi...

The Gilbert damping of ferromagnetic materials is arguably the most important but least understood phenomenological parameter that dictates real-time magnetization dynamics. Understanding the physical origin of the Gilbert damping is highly relevant to developing future fast switching spintronics devices such as magnetic sensors and magnetic random access memory. Here, we report an experimental...