Title of Dissertation: DEVELOPMENT OF MAGNETORHEOLOGICAL FLUID ELASTOMERIC DAMPERS FOR HELICOPTER STABILITY AUGMENTATION Wei Hu, Doctor of Philosophy, 2005 Dissertation directed by: Professor Norman M. Wereley Department of Aerospace Engineering Conventional lag dampers use passive materials, such as elastomers, to dissipate energy and provide stiffness, but their damping and stiffness levels d...

The main purpose of this paper is to study various configurations of a magnetorheological (MR) damper valve and to evaluate their performance indices typically dynamic range, valve ratio, inductive time constant and pressure drop. It is known that these performance indices (PI) of the damper depend upon the magnetic circuit design of the valve. Hence, nine valve configurations are considered fo...

Particle swarm optimization (PSO) technique has achieved a considerable success in solving nonlinear, nondifferentiable, multi-modal optimization problems. Currently, PSO is broadly applied in several scientific and engineering optimization applications. This paper introduces an identification of magnetorheological (MR) damper’s parameters using the PSO algorithm to introduce a more simple and ...

In this paper, the efficacy of magnetorheological (MR) dampers for seismic response reduction is examined. To investigate the performance of the MR damper, a series of experiments was conducted in which the MR damper is used in conjunction with a recently developed clipped-optimal control strategy to control a three story test structure subjected to a one-dimensional ground excitation. The abil...

This paper is concerned with a new fully adaptive control scheme for vibration isolation using a semi-active MR damper installed between ground and first floor, which is composed of two adaptive controllers. One is an adaptive inverse controller which can give necessary input voltage to MR damper so as to generate specified reference damping force to be acted on a controlled structure. The inpu...

This paper presents an approach to approximate the forward and inverse dynamic behaviours of a magnetorheological (MR) damper using evolving radial basis function (RBF) networks. Due to the highly nonlinear characteristics of MR dampers, modelling of MR dampers becomes a very important problem to their applications. In this paper, an alternative representation of the MR damper in terms of evolv...

In this research, the effect of shape parameters such as number of magnet wire turns, spools, thickness of the gap, and pole length in a Magneto-rheological (MR) fluid damper is analytically investigated and the optimization of these parameters is done with response surface method (RSM) which is combined Neuro-Fuzzy method and Particle Swarm Optimization (PSO) algorithm. Since the electro-magne...

In this paper, optimal design of hybrid low damping base isolation and magnetorheological (MR) damper has been studied. Optimal hybrid base isolation system has been designed to minimize the maximum base drift of low damping base isolation system where for solving the optimization problem, genetic algorithm (GA) has been used. In design procedure the maximum acceleration of the structure has ...

Based on theoretical analysis and experiments, this article proposes a new model for a magnetorheological (MR) damper. The proposed model with a smooth and concise form can interpret the bi-viscous and hysteretic behaviors of the MR damper very well. The parameters in the model have definite physical meanings. The bi-viscous and hysteretic behaviors can be characterized by two parameters 0 and ...

This paper is concerned with efficient integration of bilinear H∞ control and adaptive inverse control to attain vibration isolation of structure installed with a semi-active MR damper in which its damping force is controllable by input voltage. The structure with MR damper is expressed by a bilinear dynamic equation. The role of the bilinear H∞ controller is to provide the desired damping forc...