A limitation of a simple linear mass-spring model in describing goal directed movements is that it generates rather slow movements when the parameters are kept within a realistic range. Does this imply that the control of fast movements cannot be approximated by a linear system? In servo-control theory, it has been proposed that an optimal controller should control movement velocity in addition...

The effects of amine functionalization of carbon nanotubes (CNTs) and CNTs weight percent (wt. %), on the first bending natural frequencies and damping properties of CNT/epoxy composites are investigated in this paper. CNTs and amine functionalized CNTs (AFCNTs), with two different weight percentages, are used to manufacture the beam shaped specimens. Epoxy, CNT/epoxy (0.25 and 0.5 wt. % of CNT...

this paper presents a new strategy based on multi-stage fuzzy (msf) pid controller based on artificial bee colony (abc) for damping power system stabilizer (pss) in multi-machine environment. the recent studies in artificial intelligence demonstrated that the abc optimization is strong intelligent method in complicated stability problems. also, finding the parameters of pid controller in power ...

This paper aims at testing and modeling business-cycle asymmetries within a structural time-series framework, allowing for smooth transition in the parameters characterizing the cyclical component, namely, the damping factor and the frequency. An LM test of linearity is derived, and illustrations are provided with reference to a set of quarterly U.S. industrial production series for two-digit m...

A closed form solution for characterizing voltage-based signals in an RLC tree is presented. This closed form solution is used to derive figures of merit to characterize the effects of inductance at a specific node in an RLC tree. The effective damping factor of the signal at a specific node in an RLC tree is shown to be a useful figure of merit. As the effective damping factor of a signal incr...

The paper describes an investigation of the effect of structural damping in the torsion mode on wing flutter with the object of finding circumstances in which damping reduces the flutter speed. The drop in flutter speed can be considerable (25 per cent) and extend to very large values of structural damping. The effect is most apparent when the relative density (wing to air) is high, and when th...

Based on the theoretical analysis and experimental study of pneumatic damping behaviour for the valves in the reciprocating compressor, this paper presents a simple mathematical model of pneumatic damping valves, in which the non-viscous damping force is introduced. The non-viscous damping coefficient is obtained by the experimental determination. The simulation results of this simple model for...

The theory of damping is discussed in Newton's Principia and has been tested in objects as diverse as the Foucault pendulum, the mirrors in gravitational-wave detectors and submicrometre mechanical resonators. In general, the damping observed in these systems can be described by a linear damping force. Advances in nanofabrication mean that it is now possible to explore damping in systems with o...

In the present work, structure health monitoring (SHM) of welded steel pipes was used to diagnosis their state via vibration based damage detection techniques. The dynamic quantities such as Frequency Response Functions (FRFs), mode shapes and modal parameters from structural vibration to detect damage were measured, set on linear averaging mode, with a maximum frequency of analysis of 3.2 kHz....

This paper presents a nonlinear model of a clamped-clamped microbeam actuated by an electrostatic load with stretching and thermoelastic effects. The frequency of free vibration is calculated by discretization based on the Differential Quadrature (DQ) Method. The frequency is a complex value due to the thermoelastic effect that dissipates energy. By separating the real and imaginary parts of fr...