Magnetorheological damper

About: Magnetorheological damper is a research topic. Over the lifetime, 1324 publications have been published within this topic receiving 18459 citations.

A self-sensing magnetorheological damper with power generation

Abstract: Magnetorheological (MR) dampers are promising for semi-active vibration control of various dynamic systems. In the current MR damper systems, a separate power supply and dynamic sensor are required. To enable the MR damper to be self-powered and self-sensing in the future, in this paper we propose and investigate a self-sensing MR damper with power generation, which integrates energy harvesting, dynamic sensing and MR damping technologies into one device. This MR damper has self-contained power generation and velocity sensing capabilities, and is applicable to various dynamic systems. It combines the advantages of energy harvesting—reusing wasted energy, MR damping—controllable damping force, and sensing—providing dynamic information for controlling system dynamics. This multifunctional integration would bring great benefits such as energy saving, size and weight reduction, lower cost, high reliability, and less maintenance for the MR damper systems. In this paper, a prototype of the self-sensing MR damper with power generation was designed, fabricated, and tested. Theoretical analyses and experimental studies on power generation were performed. A velocity-sensing method was proposed and experimentally validated. The magnetic-field interference among three functions was prevented by a combined magnetic-field isolation method. Modeling, analysis, and experimental results on damping forces are also presented.

Semiactive Vibration Control of Train Suspension Systems via Magnetorheological Dampers

Abstract: This paper is aimed to show the feasibility for improving the ride quality of railway vehicles with semiactive secondary suspension systems using magnetorheological (MR) dampers. A nine degree-of-freedom railway vehicle model, which includes a car body, two trucks and four wheelsets, is proposed to cope with vertical, pitch and roll motions of the car body and trucks. The governing equations of the railway vehicle suspension systems integrated with MR dampers are developed. To illustrate the feasibility and effectiveness of the controlled MR dampers on railway vehicle suspension systems, the LQG control law using the acceleration feedback is adopted as the system controller, in which the state variables are estimated from the measurable accelerations with the Kalman estimator. In order to make the MR dampers track the optimal damping forces, a damper controller to command the voltage to the current drivers for the MR dampers is proposed. The acceleration responses of the car body of the train vehicle with semiactive secondary suspension system integrated with MR dampers are evaluated under random and periodical track irregularities. This semiactive controlled system is also compared to the conventional passive suspension system using viscous dampers without MR dampers, and the secondary suspension system integrated with MR dampers in passive on and passive off modes. The simulation results show that the vibration control of the train suspension system with semiactive controlled MR dampers is feasible and effective.

Smart passive system based on magnetorheological damper

Abstract: Magnetorheological (MR) dampers are one of the most promising control devices for civil engineering applications to earthquake hazard mitigation, because they have many advantages such as small power requirement, reliability, and low price to manufacture. To reduce the responses of the controlled structure by using MR dampers, a control system including a power supply, controller, and sensors is needed. However, when a lot of MR dampers are applied to large-scale civil structures, such as cable-stayed bridges and high-rise buildings, the control system becomes complex. Thus, it is not easy to install and to maintain the MR damper-based control system. In this paper, to resolve the above difficulties, a smart passive system is proposed, which is based on an MR damper system. The smart passive system consists of an MR damper and an electromagnetic induction (EMI) system that uses a permanent magnet and a coil. According to the Faraday law of induction, the EMI system that is attached to the MR damper produces electric energy. The produced energy is applied to the MR damper to vary the damping characteristics of the damper. Thus, the smart passive system does not require any power at all. Furthermore, the output of electric energy is proportional to input loads such as earthquakes, which means the smart passive system has adaptability by itself without any controller or corresponding sensors. Therefore, it is easy to build up and maintain the proposed smart passive system. To verify the effectiveness of the proposed smart passive system, the performance is compared with that of the normal MR damper-based control system. The numerical results show that the smart passive system has comparable performance to the normal MR damper-based control system.