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...

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...

A stochastic change detection methodology for reliable monitoring complex nonlinear dynamic systems is proposed. For a semi-active magneto-rheological (MR) damper, the non-parametric, data-driven restoring force method was used to identify the nonlinear dynamic damping device. Both supervised and unsupervised statistical pattern recognition techniques were used to detect the changes in the phys...

This paper describes the development of a numerical finite element algorithm used for the analysis of reinforced concrete structure equipped with shakes energy absorbing device subjected to earthquake excitation. For this purpose a finite element program code for analysis of reinforced concrete frame buildings is developed. The performance of developed program code is evaluated by analyzing of ...