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PL
W pracy przeprowadzono analizę harvestera działającego w oparciu o zjawisko Faradaya, który będzie wykorzystany do zasilania liniowego tłumika magnetoreologicznego (MR). Opisano budowę harvestera, podając jego parametry geometryczne i magnetyczne. Przedstawiono wyniki obliczeń numerycznych harvestera dla dwóch wariantów połączeń uzwojenia cewki. Wyznaczono rozkład indukcji magnetycznej i siłę zaczepową w harvesterze oraz przeanalizowano jego działanie w stanie jałowym i w stanie obciążenia cewką sterującą tłumika MR. Zwrócono uwagę na możliwość pracy harvestera jako czujnika prędkości.
EN
This study investigates the performance of an energy harvester, utilizing the Faraday's law, used to supply a linear magnetorheological (MR) damper. The structural design of the harvester is outlined and its geometrical and magnetic parameters are summarised. The numerical calculation data were obtained for two variants of coil winding connections. Distribution of magnetic flux density and the cogging force are obtained both under the idle run and under the load applied to the control coil of the MR damper. It is demonstrated that the harvester can be operated as a velocity sensor.
EN
The study investigates the behaviour of three-layered cantilever sandwich beams filled with magnetorheological fluids (MRFs) differing in the iron particle content by volume. Outer layers are made of aluminium, the space between them is sealed with silicone rubber. Two types of beams are considered: fully filled beams and partially filled beams, subjected to the magnetic field. The aim of the study is to determine stiffness and damping characteristics in relation to the magnetic field strength and the actual location where the magnetic field acts upon the beam. For this purpose, measurements have been taken of the beam free vibration response for various magnetic field strength levels and for various positions of the electromagnet located along the beam axis. Basing on the developed measurement data processing algorithm, the influence of the vibration amplitude on the natural frequency and a dimensionless damping coefficient have been determined. Finally, the equivalent natural frequency and the dimensionless damping coefficient have been derived accordingly, and the stiffness and damping ratio have been determined in function of the magnetic field strength, the electromagnet position and the MRF iron particle content by volume.
EN
The paper summarises the results of laboratory testing of an energy harvesting vibration reduction system based on a magnetorheological (MR) damper whose control circuit incorporates a battery of bipolar electrolytic capacitors (current cut-off circuit). It is designed to reduce the undesired effects in vibration reduction systems of this type, associated with the increasing amplitude of the sprung mass vibration under the excitation inputs whose frequency should exceed the resonance frequency of the entire system. Results have demonstrated that incorporating a current cut-off circuit results in a significant decrease of sprung mass vibration amplitudes when the frequency of acting excitation inputs is higher than the resonance frequency.
EN
This paper investigates the performance of electromagnetic vibration harvesters that can be incorporated in energy harvesting magnetorheological (MR) dampers. The study outlines the structure and operating principles of harvesters and compares results of numerical calculations with measurement data obtained under idle run. Results demonstrate the potential applications of harvesters as velocity sensors. The relationship between electromotive force (emf) and velocity across the devices is established. The discussion section suggests that power generation by harvesters can provide the velocity information by utilising the sensing function applicable to a variety of control algorithms.
PL
W artykule przedstawiono wyniki analizy numerycznej elektromagnetycznego przetwornika energii przeznaczonego do zasilania obrotowego tłumika magnetoreologicznego (MR). Opisano budowę i działanie przetwornika. Wyznaczono rozkład indukcji pola magnetycznego w przetworniku i siłę elektromotoryczną indukowaną w jego uzwojeniu. Obliczono przebiegi czasowe napięcia, prądu i mocy chwilowej w obwodzie zakładając, że cewka sterująca tłumika MR jest reprezentowana przez dwójnik RL. Wyznaczono zależności prądu i mocy przetwornika od prędkości obrotowej. Wyniki analiz numerycznych potwierdzono przeprowadzając badania doświadczalne przetwornika.
EN
The article presents a numerical analysis of an electromagnetic energy converter designed to power a magnetorheological damper (MR). It describes the construction and the operation of the converter. The distribution of the magnetic field in the transducer and the electromotive force induced in its coil were determined. The time patterns of voltage, current and instantaneous power in the circuit were calculated assuming that the control coil of the MR damper was represented by a two-terminal circuit RL. Moreover, the current and the power of the transducer were determined versus the rotary speed. Numerical results were confirmed in the simulations the experimental tests.
EN
The study investigates the performance of a semi-active vehicle engine mount incorporating an MR damper working in the squeeze mode (MRSQD), summarising its design, operating principles and key characteristics. The mathematical model of the mount is formulated based on the newly developed MRSQD. Two control algorithms are proposed for MRSQD control. The first algorithm (ALG1) uses the inverse model of the engine-frame system, the other is the sliding mode algorithm (ALG2). The effectiveness of the engine mount system is demonstrated in computer simulation.
EN
The study deals with the pinch mode of magnetorheological (MR) fluids’ operation and its application in MR valves. By applying the principle in MR valves a highly non-uniform magnetic field can be generated in flow channels in such a way to solidify the portion of the material that is the nearest to the flow channel’s walls. This is in contrary to well-known MR flow mode valves. The authors investigate a basic pinch mode valve in several fundamental configurations, and then examine their magnetic circuits through magnetostatic finiteelement (FE) analysis. Flux density contour maps are revealed and basic performance figures calculated and analysed. The FE analysis results yield confidence in that the performance of MR pinch mode devices can be effectively controlled through electromagnetic means.
EN
The study summarises the results of experimental examination of velocity sensing capability in a prototype of a magnetorheological damper with power generation (MRD). The device has two main components: an electromagnetic power generator and an MR damper. The study outlines the structure of the device with the main focus on the generator part, and provides results of tests performed under the idle run. The discussion of demonstrates the potentials of MRD action as a velocity-sign sensor and presents key issues which need to be addressed to enable its real life applications.
EN
The study summarises the experimental examination of an automotive magnetorheological (MR) shock absorber under electrical and mechanical excitations, investigates its current and force responses and the energy dissipation in the system. The aim of experiments was to acquire measurement data that allows in next step of the research program to engineer an energy harvesting device for the absorber. The work covers basic technical data of the absorber, description of the experimental set-up, scenario of testing program and test results of the device. Of particular importance is the influence the operating current, piston displacement amplitude and piston velocity have on the absorber’s response.
EN
This study investigates the behaviour of MR fluids in the oscillatory compression squeeze mode. Experiments were performed on commercially available MR fluids in the purpose-built experimental set-up. The influence of MR fluid’s properties and magnetic flux density on the force generated during the squeeze mode was investigated.
EN
A physical model of a vehicle engine mount incorporating a magnetorheological (MR) damper in squeeze mode is investigated and the structural design and operating characteristics of the MR damper are provided. The mathematical model of an engine mount is formulated. Kinematic excitations are assumed to be those emulating road profile-chassis (car body) interactions. Simulations of engine vibration are performed to determine the efficiency of the proposed engine mount. Conclusions are drawn concerning the potential applications of the MR damper in vehicle engine mounts.
PL
W pracy opisano budowę modelu fizycznego zawieszenia silnika samochodowego, w którym zastosowano tłumik z cieczą magnetoreologiczną (MR) działającą w trybie ściskania. Sformułowano model matematyczny zawieszenia. Zakładając wymuszenie kinematyczne modelujące oddziaływanie nierówności drogi na karoserią, przeprowadzono symulacje komputerowe drgań silnika. Oceniono efektywność działania zawieszenia oraz sformułowano wnioski dotyczące możliwości zastosowania tłumika MR w zawieszeniu silnika samochodowego.
EN
The study investigates an energy harvesting system utilising rotary motion. The system has three components: a rotary MR damper to vary the damping characteristics, a rotary power generator (energy extractor) producing electrical power, and a conditioning electronics unit to interface directly with the damper and the generator. The objective of the study is to examine the system performance through experiments. The paper outlines the structure of the damper and the generator, provides selected results of examination of the system components and the whole system under idle run and under load for the assumed speed range. The results demonstrate that the system is adaptable to external excitations, does not require an extra power supply and provides a smart solution with potential applications to rotary motion control.
EN
The paper deals with an MR damper-based vibration reduction system with energy harvesting capability. The main part of the system creates an MR damper and a power generator based on an electromagnetic transduction mechanism, which are integrated into a stand- -alone device (so called energy harvesting MR damper). The main objective of the work is to evaluate performance of the proposed vibration reduction system employed in a single DOF mechanical structure. The material outlines the design structure and characteristics of the energy harvesting MR damper, presents the vibration reduction system based on this damper and explores experimental testing of the system implemented in a single DOF mechanical structure. To demonstrate that the devised system is feasible, performance figures maps completed by experimental data are shown.
14
Content available remote Numerical study of a two-way MR mount in squeeze-mode
EN
In the paper, the authors present the results of a numerical study of a magnetorheological (MR) damper prototype operating in the so-called squeeze mode. The analyzed prototype allows achieving a symmetrical response in both directions of piston motion. The authors show the results of magnetostatic analyses of the electro-magnetic circuit of the device and lumped parameter model using calculations of the control circuit and the damping force output.
PL
W artykule przedstawiono wyniki obliczeń prototypowej konstrukcji tłumika z cieczą MR działającej w trybie ściskania. Analizowany prototyp pozwala uzyskać identyczny zakres sił tłumienia w obu kierunkach ruchu. Autorzy prezentują osiągi tłumika oszacowane na podstawie obliczeń polowych oraz obliczeń z wykorzystaniem modelu o parametrach skupionych.
EN
The study summarises the results of quasi-static experimental tests of an MR squeeze-mode damper prototype (MRSQD) performed at the MTS testing machine. Of particular interests was the influence of MR fluid clumping behaviour in the MRSQD working gap on the force output of the device. The MRSQD tests were assessed by measuring the damping force output at prescribed sinusoidal displacement inputs and at various (fixed) voltage levels resulting in the respective average current levels in the control coil. The influence of piston position offset on the damping force was also investigated. The collected data were shown in the form of damping force time histories and damping force-piston displacements loops and discussed with respect to MR fluid clumping behaviour.
EN
The study investigates the behaviour of an electrical interface incorporated in a MR damper-based vibration reduction system powered with energy recovered from vibration. The interface, comprising the R, L and C elements, is connected in between the coil in an electromagnetic electric generator and the control coil in the MR damper and its function is to convert the output voltage from the generator. The interface model was formulated and computer simulations were performed to find out how the parameters of the interface should influence the frequency responses of the vibration reduction system.
17
PL
W pracy opisano wyniki symulacji numerycznych obwodu sterującego tłumika z cieczą MR działającą w trybie ściskania. Określono wpływ wysokości szczeliny roboczej i prądu na strumień magnetyczny skojarzony z obwodem sterujacym. Zakładając harmoniczny ruch tłoka, obliczono prąd w obwodzie sterującym przy zasilaniu napięciem stałym i danych wysokościach szczeliny roboczej. Wyznaczono przykładowe charaterystyki tłumika, przedstawiające zależność wytwarzanej siły od wysokości szczeliny roboczej dla przyjetych wartości prądu.
EN
The paper summarises the results of numerical simulations of a control circuit for an MR damper operated in squeeze mode. The influence of the control gap height and current level on magnetic flux linkage was established. Assuming the piston motion to be harmonic, the current in the control circuit was computed under the constant-voltage supply conditions and for the specified gap heights. Damper force vs gap height plots obtained for the specified current levels are provided as an example of damper characteristics.
PL
W pracy przeprowadzono obliczenia polowe nowej konstrukcji tłumika z cieczą MR działającą w trybie ściskania. Wyznaczono rozkład indukcji magnetycznej w tłumiku, zależność składowej osiowej indukcji od promienia szczeliny roboczej oraz zależność średniej wartości modułu indukcji i siły oddziaływania magnetycznego w komorze kompensacyjnej od wysokości szczeliny roboczej.
EN
Calculations were performed to find the field parameters of a new-design MR damper operated in the squeeze mode: distribution of magnetic field density in the damper, the relationship between the axial component of induction and the gap radius and the relationship between the average value of induction modulus, and the magnetic interaction force inside the compensation unit and the gap height.
PL
W pracy przedstawiono wyniki symulacji numerycznych zjawisk elektromagnetycznych zachodzących w tłumiku z cieczą MR działającą w trybie ściskania. Wyznaczono rozkład pola magnetycznego w tłumiku, zależność składowej osiowej indukcji magnetycznej i indukcyjności cewki sterującej od wysokości szczeliny roboczej, rozkład gęstości mocy strat wiroprądowych oraz siłę zaczepową.
EN
The paper summarises the results of numerical simulations of electromagnetic phenomena in an MR damper operated in squeeze mode. Cognisance is taken of the magnetic field distribution and the relationship is found between the axial component of magnetic induction and inductance of the control coil and the gap height. The power spectral density of losses due to eddy currents and the cogging force are determined, too.
PL
W pracy zawarto opis stanowiska do badań semiaktywnego zawieszenia silnika samochodowego, w którym zastosowano tłumik MR. Przedstawiono założenia projektowe oraz wyszczególniono elementy mechaniczne konstrukcji stanowiska, budowę układu redukcji drgań oraz tor pomiarowy. Zamieszczono wyniki symulacji drgań silnika spalinowego umieszczonego na stanowisku z przewidzianym przez producenta pasywnym układem redukcji drgań oraz z zaproponowanym semiaktywnym układem redukcji drgań z tłumikiem MR. Porównując wyniki obliczeń w obu przypadkach, przeprowadzono weryfikację założeń dotyczących konstrukcji układu redukcji drgań.
EN
The facility is purpose-built for testing semi-active engine mounts complete with an MR damper. The design objectives for the adopted mechanical structure are summarized and components of vibration reduction system as well as measurement equipment are described. Simulation experiments were performed to test the engine vibrations when placed in the facility and provided with the typical standard passive vibration reduction system and with the proposed new semi-active vibration reduction system incorporating an MR damper. Calculation data are compared and the design objectives are verified.
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