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1
EN
Magnetostrictive TbxHo0.8−xPr0.2Fe1.8Mn0.1 (0 ⩽ x ⩽ 0.20) alloys are prepared by arc-melting and subsequent annealing. The dopant of Pr/Mn introduced into RFe2 compounds effectively stabilizes the forming of single C15 Laves phase at ambient pressure. The easy magnetization direction (EMD) varies when Tb content increases, which is accompanied by a crystalstructural transition. EMD lies along ‹1 0 0› axis for x ⩽ 0.05, rotating to ‹1 1 1› axis for x ⩽ 0.12, with a tetragonal symmetry changing to a rhombohedral one. Magnetocrystalline-anisotropy compensation is obtained with the optimized composition of x = 0.12, shifting to the Tb-poor side in comparison to Pr/Mn-free counterpart. An enhanced effect on magnetoelastic properties is achieved in Tb0.12Ho0.68Pr0.2Fe1.8Mn0.1, which simultaneously possesses a low anisotropy and high magnetostriction performance, i.e. λs ~ 420 ppm, λ111 ~ 970 ppm, and a large low-field λa ~ 390 ppm/2 kOe, being 30 % higher than that of Pr/Mn-free compound. Combining low-cost light rare earth Pr with the lower Tb content, Tb0.12Ho0.68Pr0.2Fe1.8Mn0.1may make it promising solution in magnetostrictive applications.
EN
The paper presents the analysis of the magnetic sensor’s applicability to the energy harvesting operations. The general scheme and technical advancement of the energy extraction from the electric vehicle (such as a tram or a train) is presented. The proposed methodology of applying the magnetic sensor to the energy harvesting is provided. The experimental scheme for the sensor characteristics and measurement results is discussed. Conclusions and future prospects regarding the practical implementation of the energy harvesting system are provided.
EN
TbxHo0.9−xNd0.1(Fe0.8Co0.2)1.93/epoxy (0 ⩽ x ⩽ 0.40) composites are fabricated in the presence of a magnetic field. The structural and dynamic magnetoelastic properties are investigated as a function of both magnetic bias field Hbias and frequency f at room temperature. The composites are formed as textured orientation structure of 1–3 type with 〈1 0 0〉 preferred orientation for x ⩽ 0.10 and 〈1 1 1〉-orientation for x ⩾ 0.25. The composites generally possess insignificant eddy-current losses for frequency up to 50 kHz, and their dynamic magnetoelastic properties depend greatly on Hbias. The elastic modulus (E3H and E3B) shows a maximum negative ΔΕ effect, along with a maximum d33, at a relatively low Hbias ~ 80 kA/m, contributed by the maximum motion of non-180° domain-wall. The 1–3 type composite for x ⩾ 0.25 shows an enhanced magnetoelastic effect in comparison with 0 to 3 type one, which can be principally ascribed to its easy magnetization direction (EMD) towards 〈1 1 1〉axis and the formation of 〈1 1 1〉-texture-oriented structure in the composite. These attractive dynamic magnetoelastic properties, e.g., the low magnetic anisotropy and d33,max as high as 2.0 nm/A at a low Hbias ~ 80 kA/m, along with the light rare-earth Nd element existing in insulating polymer matrix, would make it a promising magnetostrictive material system.
PL
W artykule omówiony został przegląd literatury w zakresie magnetoelektrycznych sensorów prądu. Przedstawiono charakterystyki przetwarzania mierzonego stałego pola magnetycznego na wyjściowy sygnał napięciowy otrzymany z sensora.
EN
The paper presents the review of the magnetoelectric current sensors . The possibility of output voltage measurement of the sensor in the function of DC magnetic field is also presented.
5
Content available remote Liniowy aktuator magnetoelektryczny
PL
W artykule przedstawiono realizację aktuatora w oparciu o kompozyty magnetoelektryczne. Element roboczy aktuatora wykonano w postaci kompozytu ceramicznego wykonanego w technologii Low Temperature Cofired Ceramic (LTCC) umieszczonego pomiędzy cewkami Helmholtza. W celu zwiększenia efektu magnetoelektrycznego kompozyt poddano procesowi polaryzacji elektrycznej w podwyższonej temperaturze. Spowodowało to prawie dwukrotny wzrost współczynnika magnetoelektrycznego. Wykazano, że w zakresie natężeń stałych pól magnetycznych do 2 kOe, wydłużenie elementu wykonawczego jest liniowe. Pole magnetyczne w tym przypadku można wykorzystać do sterowania wydłużeniem elementu wykonawczego aktuatora. Ponadto napięcie generowane na elektrodach elementu wykonawczego jest wprost proporcjonalne do wydłużenia w zakresie pól magnetycznych do 2 kOe.
EN
This paper presents the realization of linear actuator based on the magnetoelectric. The actuator was made as a multilayer ceramic composite using the LTCC technology and was placed between the Helmholtz coils. In order to increase magnetoelectric effect, the composite was electrically polarized at elevated temperature. Magnetoelectric coefficient of the polarized composite is two times higher than for composite without polarizing. It has been shown, that in the range of constant magnetic fields up to 2 kOe, the elongation of the actuator is linear. The magnetic field in this case can be used to control the elongation of the actuator. In addition, the voltage generated between the electrodes of the actuator is directly proportional to the magnetic field in range up to 2 kOe.
EN
Paper shows study on the magnetoelectric composite material placed in an external magnetic field with changing magnetic field vecotr. An experimental setup for investigation of magnetoelectric properties of magnetostrictive-piezoelectric material was prepared. The hybrid structure is made of magnetostrictive composite (based on Terfenol-D) and piezoelectric material. Experimental results shown the response of prepared hybrid material to the rate of changes of direction of magnetic field vector. Investigation were mainly focused on possibility of generating of electric power from prepared material. It was found that the prepared hybrid material exhibits magnetoelectric effect in the case of work when direction of magnetic field vector was changing. This effect might be use in Energy Harvesting applications.
7
Content available remote Czujnik magnetoelektryczny do pomiaru natężenia pola magnetycznego
PL
W artykule przedstawiono realizację czujnika natężenia stałego pola magnetycznego w oparciu o kompozyty magnetoelektryczne. Element czuły sensora wykonano w postaci kompozytu ceramicznego warstwowego wykonanego w technologii Low Temperature Cofired Ceramic (LTCC) umieszczonego pomiędzy cewkami Helmholtza. W celu zwiększenia efektu magnetoelektrycznego kompozyt poddano procesowi polaryzacji elektrycznej w podwyższonej temperaturze. Spowodowało to prawie dwukrotny wzrost współczynnika magnetoelektrycznego. Wykazano, że w zakresie natężeń stałych pól magnetycznych poniżej 800 Oe napięcie generowane przez czujnik jest liniowo zależne od natężenia stałego pola magnetycznego.
EN
This paper presents the implementation of sensor based on the magnetoelectric composites for measurements of magnetic field strength. The sensing element of the sensor was made as a multilayer ceramic composite using the LTCC technology and was placed between the Helmholtz coils. In order to increase magnetoelectric effect, the composite was electrically polarized at elevated temperature. Magnetoelectric coefficient of the polarized composite is two times higher than for composite without polarizing. It has been shown, that in the range of static magnetic fields below 800 Oe, the voltage generated by the sensor is linearly dependent on the strength of a constant magnetic field.
EN
TbHo0.9−xNd0.1 (Fe0.8Co0.2)Sub>1.93 (0 ≤ x ≤ 0.40) particulate composites were prepared by embedding and aligning alloy particles in an epoxy matrix with and without a magnetic curing field. The magnetoelastic properties were investigated as functions of composition, particle volume fraction and macroscopic structure of the composite. The magnetic anisotropy compensation point was found to be around x = 0.25, where the easy magnetization direction (EMD) at room temperature was detected lying along ⟨ 1 1 1 ⟩ axis. The composite with ⟨ 1 1 1 ⟩ preferred orientation and pseudo-1-3 type structure was prepared under an applied magnetic field of 12 kOe. An enhanced magnetoelastic effect and large low-field magnetostriction λa, as high as 430 ppm at 3 kOe, were obtained for Tb0.25Ho0.65 Nd0.1 (Fe0.8Co0.2)1.93composite rod. The value of λa was of 72 % of its polycrystalline alloy (~595 ppm/3 kOe) although it only contained 30 vol.% of the alloy particles. This enhanced effect can be attributed to the larger λ111 (as compared to λ100), low magnetic anisotropy, easy magnetization direction (EMD) along the ⟨ 1 1 1 ⟩ axis and ⟨ 1 1 1 ⟩-textured orientation of the alloy particles as well as the chain-like structure of the composite. The good magnetoelastic properties of the composite, in spite of the fact that it contained only 30 vol.% of the alloy particles with light rare-earth Nd element in the insulating epoxy, would make it a potential material for magnetostriction application.
EN
The paper considers the influence of core saturation on the dynamics of magnetostrictive fast-acting actuator. The field-circuit mathematical model of the dynamic operation of the capacitor-actuator system is applied. Two kinds of magnetostrictive core nonlinearity are taken into account. It has been proved that the saturation of the B-H curve practically does not affect the current, and capacitor voltage waveforms, but significantly affects a core elongation waveform. The computed results are compared with experimental ones.
EN
In this paper the investigations of magnetostriction as well as DC magnetic properties for composites doped with Terfenol-D particles are presented. All investigations were performed for the materials with 35%, 46% and 70% volume fraction of the Terfenol-D particles surrounded by epoxy matrix. Moreover, the bulk Terfenol-D alloy was tested. The obtained results show that the magnetization of the composite materials increases with increasing the volume fraction of Terfenol-D particles. Similar dependence as for magnetization was observed for the magnetostriction measurements. Although the magnetostriction of composite material is smaller than for solid Terfenol-D it is still tens of times bigger than in case of traditional magnetostrictive materials. Obtained results gives opportunity to use these materials for variety applications such as actuators and sensors.
11
Content available remote Właściwości magnetostrykcyjne kompozytów multiferroicznych
PL
Magnetostrykcyjne materiały kompozytowe wykazujące efekt magnetoelektryczny (ME) są obecnie szeroko badane zarówno dla celów poznawczych jak i aplikacyjnych. Szczególny nacisk kładzie się na kompozyty zawierające fazę magnetostrykcyjną i ferroelektryczną, w których efekt magnetoelektryczny jest znacznie większy niż w materiałach jednofazowych. W opracowaniu przedstawiono warunki syntezy oraz właściwości magnetostrykcyjne i magnetoelektryczne kompozytów ceramicznych składających się z magnetycznych warstw ferrytu NiZnCuFe2O4 rozdzielonych warstwami ferroelektryka BaTiO3 . Kompozyt warstwowy posiada znacznie większą magnetostrykcję i prawie dwukrotnie większy współczynnik magnetoelektryczny od najlepszego kompozytu proszkowego. W porównaniu do kompozytów prezentowanych w literaturze badane materiały posiadają relatywnie wysokie współczynniki magnetoelektryczne co sprawia, że mogą być zastosowane w sensorach, aktuatorach i przetwornikach ultradźwiękowych.
EN
Magnetoelectric effect (ME) in magnetostrictive materials are intensively studied for his fundamental interest and his practical applications. The ME effect observed for single phase materials is usually small. Much larger effect can be obtained in composites consisting of two functional phases: magnetostrictive phase, in which a strain is produced by application of a magnetic field and piezoelectric phase, in which a change in electric polarization is produced by an applied stress. In this paper the synthesis, magnetostriction and magnetoelectric effect of bulk and multilayer composites consisting of ferroelectric (BaTiO3) and ferrite layers (NiZnCuFe2O4) was investigated. The magnetostriction and magnetoelectric coefficient of multilayer composite is markedly higher than that of bulk ceramic composite. Compared to other composites presented in literature, the presented materials possess relatively high magnetoelectric effect, and may be applied in sensors, actuators and ultrasonic transducers.
12
Content available remote O potencjalności operatora zadania brzegowego magnetostrykcji
EN
In this study a boundary problem of magnetostriction was formulated in a operational form. It has been demonstrated that the issue operator is potential in the relation to the defined bilinear form. Such a property of the operator gives possibility to formulate the variational functional of magnetostriction, which allows to search for approximate solutions by its minimalization.
13
Content available remote Obliczanie hałasu emitowanego przez transformatory
PL
Artykuł przedstawia metodę obliczania hałasu emitowanego przez transformatory trójfazowe w różnych warunkach zasilania i obciążenia. Zaproponowano teoretyczną metodę obliczania harmonicznych drgań magnetostrykcyjnych rdzeni i ich wykorzystania do przybliżonego obliczania hałasu emitowanego przez transformatory. W rozważaniach przeprowadzonych w zakresie częstotliwości od 50 do 1000Hz uwzględniono także hałas emitowany przez uzwojenia i specyfikę transformatorów przekształtnikowych. Określono współczynniki wzrostu hałasu wypadkowego transformatora przekształtnikowego wynikające z hałasu uzwojeń wiodących niesinusoidalne prądy.
EN
This paper presents a method for calculating the noise emitted by the three-phase transformers operating with different values of load current and for different values of supply voltage (induction in the core). The theoretical method to determine the content of higher harmonics of magnetostrictive vibrations of the cores was developed. The discussion carried out in the frequency range from 50 to 1000 Hz is also taken into account the specificity of converter transformers. For the three-phase converter transformers the factors have been identified responsible for the increase of the noise due to vibration of transformer windings with nonsinusoidal currents.
14
EN
The paper deals with a magnetostrictive fast-acting actuator applied as a driving device for plasma valve. The actuator is characterized by a relatively small displacement (les then 0.1 mm), but with a very short response time – below 0.1 ms. System is designed for so called “high intensity plasma pulses gun” which is applied in the area of plasma physics and material engineering [1]. A structure with an axisymmetrical actuator energised by discharged pulses of a capacitor has been proposed. The field-circuit mathematical model of the dynamic operation of the actuator has been applied. The model includes: the equation of transient electromagnetic field in a non-linear ferromagnetic material and equation of electric circuit. Using the Borland Delphi 9.0 environment, the computer software has been elaborated. Results of simulation are presented.
15
Content available Polowo-obwodowy model aktuatora magnetostrykcyjnego
PL
W artykule przedstawiono model matematyczny zjawisk elektromagnetycznych w szybkoreagującym aktuatorze magnetostrykcyjnym. Aktuator jest przeznaczony do napędu zaworu doprowadzającego medium (najczęściej gaz) do komory roboczej impulsowego działa plazmowego, służącego do badań w zakresie fizyki ciała stałego, fizyki plazmy oraz inżynierii materiałowej [1]. Urządzenie charakteryzuje się stosukowo małym krokiem roboczym (poniżej 0,1 mm), ale bardzo krótkim czasem reakcji – rzędu kilkudziesięciu mikrosekund. Zaproponowano aktuator o strukturze osiowosymetrycznej. Walcowy magnetostrykcyjny rdzeń jest umieszczony wewnątrz cylindrycznej cewki zasilanej impulsami prądowymi z baterii kondensatorów. Opracowano polowo-obwodowy model nieustalonych zjawisk elektromagnetycznych w układzie. Model obejmuje równania opisujące nieustalone pole magnetyczne w nieliniowym środowisku ferromagnetycznym oraz równanie obwodu elektrycznego z uwzględnieniem pojemności. Wykorzystując środowisko Borland Delphi opracowano program komputerowy umożliwiający symulację zjawisk nieustalonych. Zaprezentowano wybrane wyniki symulacji.
EN
The paper deals with a magnetostrictive fast-acting actuator applied as a driving device for plasma valve. The actuator is characterized by a relatively small displacement (of the order of tens of microns), but with a very short response time – below 100 microseconds. System is designed for so called “plasma gun” which is applied in the area of plasma physics and material engineering. A structure with an axisymmetrical actuator energised by discharged pulses of a capacitor has been proposed. The field-circuit mathematical model of the dynamic operation of the actuator has been proposed. The model includes: the equation of transient electromagnetic field in a non-linear ferromagnetic material and equation of electric circuit. Using the Borland Delphi environment, the computer software has been elaborated. Results of simulation are presented.
EN
The coupling of the propagating stress wave with the eddy current model is presented. The applied stress produces magnetization in the sample that can be measured outside the sample by measuring the resulting magnetic flux density. The stress and flux density measurements are made on a mechanically excited steel bar. The problem is modelled with the finite element method for both the propagating wave and the eddy current. Three aspects are considered: eddy current model using magnetization from the measurements, coupled wave and eddy current models, and coupled different dimensions in the wave model. The measured stress can be reproduced from the measured flux density by modelling. The coupled models work both for stress and flux couplings as well as for the different dimensionality couplings.
17
Content available remote Zasada wzajemności w magnetostrykcji
EN
The paper contains derivation of reciprocity principle for boundary problem of magnetostriction. The results obtained in this work can become the theoretical basis to formulate the numerical solutions of different scientific and engineering problems connected with magnetostrictive materials.
18
Content available remote Zasada wariacyjna magnetostrykcji
EN
The paper shows how to transform a given nonlinear boundary problem of magnetostriction into a variational formulation. A sufficient condition for the construction of variational principle is formulated in the theorem of VAINBERG. The results obtained in this work can become the theoretical basis to formulate the numerical solutions of different scientific and engineering problems connected with magnetostrictive materials.
EN
In the paper, a construction and principle of working of a giant magnetostrictive actuator have been presented. The effects of varied operating conditions such as magnetic bias and mechanical prestress on the magnetostriction characteristics is discussed. The magnetic circuit of the actuator is analyzed using finite element method. The selected results of calculations are presented.
PL
W pracy omówiono budowę i zasadę działania magnetostrykcyjnego aktuatora z rdzeniem wykonanym z Terfenolu-D. Analizowano wpływ namagnesowania i naprężenia wstępnego rdzenia z Terfenolu-D na pracę magnetostrykcyjnego aktuatora. Do wyznaczania rozkładu pola wykorzystano metodę elementów skończonych. Przedstawiono wybrane wyniki obliczeń symulacyjnych.
PL
W artykule przedstawiono analizę drgań i hałasu emitowanego przez trójfazowy transformator zasilający układy prostownikowe jednokierunkowe i mostkowe. Przedstawiono analizę drgań i poziomu emitowanego hałasu dla różnych wartości prądów obciążenia transformatora i różnych wartości napięcia zasilającego, czyli indukcji w rdzeniu. Określono wpływ drgań i hałasu uzwojeń na hałas całkowity emitowany przez transformator prostownikowy. Wykonana została analiza harmoniczna drgań i emitowanego hałasu w przedziale od 50 do 1000 Hz.
EN
This paper presents an analysis of vibration and noise emitted by the three-phase transformer feeding the single way convertor sets as well as double way (bridge) ones. The harmonic analysis of vibration and noise emitted by the core and windings of transformer was done with different values of load current and for different values of supply voltage (induction in the core). It was determined, the influence of vibration and noise of the windings on the total noise emitted by the rectifier transformer. Harmonic analysis of vibration and noise was carried out in the range from 50 to 1000 Hz.
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