Development of an energy-harvesting magnetorheological fluid damper

Due to the unique property of magnetorheological (MR) effect, the MR-base device takes the advantage in rapid response, large dynamic range in strength and low energy consumption. In the last several decades, MR damper is becoming one kind of very promising smart device in the dynamic vibration control systems. It is noted in many current research that the MR damper can be integrated with the energy harvest system into one device. The energy-harvesting magnetorheological (EHMR) damper saw the possibility to produce a certain amount of energy from mechanical vibration. In some research, the recovery energy can be invoked as the dynamic signals to determine the velocity and displacement of the MR damper. As the result, the new EHMR damper saw the possibility to reduce the power consuming. This multi-function MR damper is considered to be one of the most ideal solution to improve the application of the MRbase device in lower energy requirement, better reliability and more flexible arrangement. In this thesis, the full study is dedicated to investigate and design an EHMR damper. Conceptions, operating principle and mathematical methods in design of EHMR damper are studied. The process of design, material selecting and evaluation, numerical design methods is discussed. Finite-element analysis is investigated to evaluate the distribution of magnetic field and isolation of magnetic interference. Mathematical model is investigated and optimized to study the nonlinear mechanical property of MR fluid. The prototype of the EHMR damper is designed, fabricated and tested. Evaluation of energy generation efficiency and self-sensing algorithm is varied out. The damping property of the EHMR damper and each individual function, including energy recovery property and self-sensing capability are experimentally validated including the dynamic working range. The power generated criterion, sensing property and sensing reliability. The test result illustrates that the proposed EHMR damper, can provide around 350% dynamic damping range under 0.6A driving current. While the proposed energy harvest system can provide a minimized cogging force, and recover a certain amount of power, when working with the MR damper. In addition, the generated power can accurately determine the relative velocity and displacement of the damping system