The paper presents the methodology for designing knowledge based power system stabilizers (PSSs). The proposed methodology relies on extensive nonlinear digital or analog simulation to detect correlation patterns between input damping states and the PSS output signal. Use of linear and nonlinear least square regression analysis results in a linear and nonlinear state feedback structure that is ...

The boring operation is a very critical manufacturing process which created surface roughness, tool wear, noise and vibration related problems. A deep internal boring operation in a workpiece is a classic example of chatter-prone machining. This review focuses on study of new damping composite materials for boring tool and introduces new advance viscoelastic materials for vibration attenuation ...

The Sirri jacket offshore platform was designed and installed in Persian gulf of Iran in 1975 and has been in service since that time. The importance of offshore structure's stability and the failure of this kind of structure during an earthquake in different active zones revealed that earthquake loading has to be considered. In this paper, Magnetorheological (MR) fluid dampers have been propos...

Stability Improvement of Grid-connected Converter with LCL Filter based on Capacitor Current Active Damping by Computational Delay Reduction

This paper discusses the controller design of a PZTactuated suspension dual-stage servo system in hard disk drives. The proposed control structure includes an active vibration damping control loop and a trackfollowing control loop. The vibration damping control loop, which runs at a faster rate than the trackfollowing control loop, utilizes a PZT element on a PZT-actuated suspension as a vibrat...

local site conditions have a strong effect on ground response during earthquakes. two important soil parameters that control the amplification effects of seismic motions by a soil column are the soil hysteretic damping ratio and shear wave velocity. this paper presents the results of in situ damping ratio measurements performed using continuous surface wave attenuation data at a site in semnan ...

Two types of piezoelectric wafer active sensor (PWAS) oscillators, Colpitts-type PWAS oscillator and series-type PWAS oscillator, designed for in-vivo monitoring of capsule formation around soft tissue implants have been presented. Both of the oscillators were explored analytically and experimentally. Colpitts-type PWAS oscillator uses the inductive property of the PWAS in its resonant frequenc...

damping of a full-scale cable with a pair of passive–on magnetorheological (mr) dampers was tested. a cable of 215.58m long with the first mode frequency of 0.658hz was tensioned horizontally in cable prefabrication factory. two mr dampers were attached to the cable in an angle in the plane perpendicularly to the cable axis in 5m length from the cable anchorage. the applied voltage level was 0v...

Studied here is the large-time behavior of solutions of the Korteweg-de Vries equation posed on the right half-line under the effect of a localized damping. Assuming as in [20] that the damping is active on a set (a0,+∞) with a0 > 0, we establish the exponential decay of the solutions in the weighted spaces L((x + 1)dx) for m ∈ N∗ and L(edx) for b > 0 by a Lyapunov approach. The decay of the sp...

Current active vibration suppression systems usually consist of piezoelectric extension actuators bonded to the surface or embedded within the structure. The use of piezoelectric shear actuators/sensors has been proposed as an alternative, where the electric field is applied perpendicular to the direction of polarization to cause shear deformation of the material. We present an exact analysis a...