Marcin Węgrzynowski

Investigation of an energy harvesting MR damper in a vibration control system

In this paper the authors investigate the performance of an energy harvesting MR damper (EH-MRD) employed in a semi-active vibration control system (SVCS) and used in a single DOF mechanical structure configuration. Main components of the newly proposed SCVS include the MR damper and an electromagnetic vibration energy harvester based on the Faradays law (EVEH) that converts vibration energy into electrical energy and delivers electrical power supplying the MR damper. The main objective of the study is to indicate that the SVCS, controlled by the specially designed embedded system, is feasible and presents good performance at the present stage of the research. The work describes investigation the unique features of the EH-MRD, i.e. its self-powering and self-sensing capabilities. Two cases were considered and the testing was done accordingly. In the case 1, only the self-powered capability was investigated. It was found out that harvested energy is sufficient to power the EH-MRD damper and to adjust it to structural vibration. The results confirmed the adequacy of the SVCS and demonstrated a significant reduction of the resonance peak. In the case 2, both the self-powering and self-sensing capabilities were investigated. Due to the self-sensing capability, the SCVS does not require any sensor. It appeared that thus harvested energy is sufficient to power the EH-MRD and enables self-sensing action since the signal of voltage induced by EVEH agrees with the relative velocity signal across the device. Similar to case 1, the resonance peak is significantly reduced.

Experimental Tests of an Electromechanical Transducer of Reverse Linear Motion into Electrical Energy

This document deals with the results of laboratory tests of an experimental electromechanical transducer for supplying an magnetorheological (MR) damper. The aim of the tests was to determine: the electromotive force induced in the sectionalized coil, the voltage and the current strength in the control coil of the damper as well as instantaneous power. The results provided are based on the tests of the transducer under periodic kinematic excitations and are compared with those achieved in numerical calculations.

FEM Analysis of a Cantilever Sandwich Beam with MR Fluid Based on ANSYS

The study covers the modeling three-layered beam incorporating a magnetorheological (MR) fluid. The beam finite element model was created using the ANSYS software. The beam comprises two outer layers made of aluminium and MR fluid layer in between, sealed with silicone rubber. Interactions of the magnetic field are taken into account by varying the parameters of the finite elements. Data required for identification were collected from results of measurement of the beams free vibrations. The identification procedure assumes the good agreement between the frequencies of the beams free vibrations and dimensionless damping coefficients obtained from research and computation data. The validity of proposed beams finite element model was also investigated. Finally some numerical results were presented.

EXPERIMENTAL SETUP FOR TESTING ROTARY MR DAMPERS WITH ENERGY HARVESTING CAPABILITY

Abstract The experimental setup has been developed for laboratory testing of electromechanical energy transducers and rotary magnetorheological (MR) dampers. The design objectives are outlined and the parameters of the key elements of the setup are summarised. The structure of the mechanical and measurement and control systems is presented. Results of functional testing of a newly developed transducer and a MR rotary damper are summarised

Magnetorheological damper–based positioning system with power generation:

This study investigates a newly developed positioning system based on a rotary magnetorheological damper with power generation capability, comprising an electromagnetic power generator (energy extractor) generating electrical power, an magnetorheological damper which alters the damping characteristics of the system and an electrical interface, connected in between the coil of the generator and the damper control coil, which conditions the voltage output from the generator. Structural configurations of the damper and the generator are outlined, and the results of their testing and the testing done on the entire system are summarised, covering the tests conducted with and without the interface, under the idle run and under load in the assumed velocity range. The objective of the work is to examine the performance of the proposed positioning system through experiments. Results of the system testing in the uncontrolled case (passive system) and in the controlled one (semi-active system) in a purpose-built test rig are compared and discussed. Three design options of the electrical system controlling the damper are explored. In the first option, the damper is assumed to be controlled starting from the initial moment of the motor shaft’s motion, and in the second option, the control action begins at the instant when the motor shaft assumes the present position. The third variant is similar to the first one except that an additional condenser is connected behind the Graetz bridge. The results confirm the adequacy of the developed positioning system and demonstrate an improvement in control of the system’s dynamic behaviour.