A new self-powered and sensing semi-active control system based on magnetorheological (MR) damper is presented. The system includes four key parts: a rack and pinion mechanism, a linear permanent magnet DC generator, a current adjustment MR damper, and a control circuit. Numerical simulations for seismic protection of elevated bridges equipped with this system excited by two historical earthqua...

The effectiveness of Metallic dampers for seismic response reduction of structures is quite well known in the earthquake engineering community. However, little attention has been paid to evaluating the influence of the number and placement of this type of dampers on the dynamic response. Using genetic algorithms as an optimization technique will allow for the simultaneous number and design of a...

This paper investigates the use of inerters for vibration suppression of a multistorey building structure. The inerter was proposed as a two-terminal replacement for the mass element, with the property that the applied force is proportional to the relative acceleration across its terminals. It completes the force-current mechanical-electrical network analogy, providing the mechanical equivalent...

This paper describes a semi-active vibration absorber (SVA) concept based on a real-time controlled magnetorheological damper (MR-SVA) for the enhanced mitigation of structural vibrations due to harmonic disturbing forces. The force of the MR damper is controlled in real-time to generate the frequency and damping controls according to the behaviour of the undamped vibration absorber for the act...

This paper looks at the effect that a mono-directional Power Take Off (PTO) has on the motions and power extraction of a Wave Energy Converter (WEC). A monodirectional damper is one where the resisting force only operates in one direction. The model comprises of a cylinder that is restrained to move in heave, reacting against an internal mass (also limited to move in heave) that is connected to...

Yaw damper represents a major source of excitation for flexural vibration of the railway carbody. In order to reduce transmissibility of such undesired excitation, yaw damper should allow for large force transmission at low working frequencies, but should behave as vibration isolator at high working frequencies. Unfortunately, the yaw oil damper (OD), which is nowadays in service, has poor intr...

In this paper, we consider the implementation of a static H∞ output feedback controller to a quarter vehicle suspension system with a semi-active magnetorheological fluid (MRF) damper. Unlike most of the existing literature, all the states in the equation of motion are relative displacements and velocities between sprung, unsprung masses and road disturbance instead, in addition the input to th...

Abstract The force response of squeeze film dampers and hydrodynamic bearings is significantly influenced by the occurence cavitation inside lubricant films. viscosity occuring mixture oil air bubbles vastly different than that pure therefore changes pressure build‐up thereby stiffness damping properties lubrication To accurately predict a damper, its effect on has to be taken into account. Wel...

A comparative analysis of different models of a Magneto-Rheological (MR) damper was done. Three models were tested: a non-linear ARX, a semi-phenomenological and a phenomenological. Although the non-linear ARX model shown the best result, this is a black-box model with limited use. However, the Semi-Phenomenological model represented an excellent option considering the physical meaning of its p...

In this paper the vibration behaviors of a structure equipped with a tuned liquid column damper (TLCD) under a harmonic type of earthquake loading are studied. However, due to inherent nonlinear liquid damping, it is no doubt that a great deal of computational effort is required to search the optimum parameters of the TLCD, numerically. Therefore by linearization the equation of motion of the s...