additional dampers are employed in order to decrease the dynamic response of structure against the earthquake and wind loading recently. in this study, two types of systems related to waste of inactive energy, i.e. frictional damper which is categorized in dampers dependent on movement and viscoelastic damper which is categorized in dampers dependent on velocity, in making steel structures resi...

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...

We designed and validated a rotary magnetorheological (MR) damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD), and a high magnetic field intensity (MFI) for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR dam...

A generic method for analysis of nonlinear forced response for bladed disks with friction dampers of different designs has been developed. The method uses explicit finite element modeling of dampers, which allows accurate description of flexibility and, for the first time, dynamic properties of dampers of different designs in multiharmonic analysis of bladed disks. Large-scale finite element da...

Long cables, such as are used in cable-stayed bridges, are prone to vibration due to their low inherent damping characteristics. Several studies have investigated the use of an optimal viscous damper attached transversely to dampen such vibration. This paper investigates the potential for improved damping using a semiactive device. The equations of motion of the cable/damper system are reviewed...

This letter reports basic acoustic phenomena related to part-pedaling in the piano. With part-pedaling, the piano tone can be divided into three distinct time intervals: initial free vibration, damper-string interaction, and final free vibration. Varying the distance of the damper from the string, the acoustic signal and the damper acceleration were measured for several piano tones. During the ...

Semi active control systems are becoming increasingly popular because they offer reliability of passive systems combined with high performance and versatility of active control systems but with low power consumptions. As Magnetorheological (MR) fluids can produce good controllable damping force under application of magnetic field, MR damper can be used as effective element in semiactive vibrati...

In order to build high-precision and highefficient MR damper system model, a multi-domain unified modeling method was proposed. Firstly, based on the analysis of a MR damper semi-active suspension system model, various fields of MR, such as structure, magnetic field, control and mechanics, were studied to find the main influencing parameters. And then for the multi-domain coupling characteristi...

Some shape memory alloys like NiTi show noticeable high damping property inpseudoelastic range. Due to its unique characteristics, a NiTi alloy is commonly used forpassive damping applications, in which the energy may be dissipated by the conversion frommechanical to thermal energy. This study presents a shape memory alloy based micro-damper, which exploits the pseudoelasticity of NiTi wires 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 ...