Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Miedzińska, D." wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 32
Tytuł:
Pianki poliuretanowe - właściwości, zastosowania, recykling
Poliurethane foams - properties, applications, recycling
Autorzy:
Barnat, W.
Miedzińska, D.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/357306.pdf
Data publikacji:
2011
Wydawca:
Politechnika Śląska
Tematy:
pianka poliuretanowa
tworzywa sztuczne
recykling
pouliurethane foam
polymers
recycling
Opis:
Pianka poliuretanowa jest tworzywem sztucznym składającym się z komórek litego poliuretanu, który otacza pęcherzyki gazu. Materiał ten może być sztywny lub podatny na odkształcenia, ale zawsze charakteryzuje się niską gęstością. Pianki najczęściej są produkowane w formie dużych bloków, które ucina się do pożądanych kształtów. Po zakończeniu okresu użytkowania poliuretany mogą być odzyskiwane w celu ponownego użycia lub poddawane recyklingowi chemicznemu. W artykule przedstawione zostały wybrane problemy związane z badaniem, zastosowaniem i w dalszej kolejności recyklingiem pian polimerowych.
Polyurethane foam refers to a number of different types of foam consisting of polymers made of molecular chains bound together by urethane links. It can be flexible or rigid, but has a low density. Flexible polyurethane is made in blocks and then cut to its desired shape. At the end of their service life, polyurethanes can be sent for reuse (for example, rebonding) or chemical recycling, or can be incinerated for energy recovery. The chosen problems connected with research, implementations and recycling of polyurethane foams were presented.
Źródło:
Archiwum Gospodarki Odpadami i Ochrony Środowiska; 2011, 13, 4; 13-17
1733-4381
Pojawia się w:
Archiwum Gospodarki Odpadami i Ochrony Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of influence of temperature on wellbore tubing dimensions
Autorzy:
Kwietniewski, M.
Miedzińska, D.
Niezgoda, T.
Małek, E.
Powiązania:
https://bibliotekanauki.pl/articles/241587.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
wellbore
tubing
heat
thermal extension
pipe
steel P110
thermal analyses
finite element method
Opis:
The construction of exploitation wellbore is complex, it consists of several columns of pipelines which perform different tasks. It is very important to preclude flow of reservoir fluid between wellbore and ground. Tubing is a kind of a pipeline which is very important element of oil and gas wellbore construction. It allows to transport fracturing medium between wellbore station and underground deposit. Manufacture quality and correct mounting of tubing in the wellbore are the key for effective exploitation. However, during work those pipes are subjected to changeable loads which results in temperature value changes for example. That temperature variations can be caused by cold medium transport inside the pipe. In the paper, analyses of influence of temperature value changes on the tubing shrinkage were presented. Numerical analyses of section of pipe vertically located in the wellbore and loaded with changeable temperature were carried out. The calculations were made with the use of coupled structural and thermal analyses. Received results of tubing shrinkage for fragment of pipe were adapted to the column of pipes of 3000 m length. Results of numerical analyses were verified with the analytical calculations. Material of tubing was assumed as steel P110 which is often applied in the wellbore construction.
Źródło:
Journal of KONES; 2016, 23, 4; 269-273
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FEM analysis of proppant sticking in rock cracks
Analiza MES wciskania proppantu w pęknięcie skalne
Autorzy:
Kwietniewski, M.
Miedzińska, D.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/231026.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analiza MES
proppant
skała łupkowa
pęknięcie
szczelinowanie
kontakt
Newmark
FEM analysis
shale rock
crack
fracturing
contact
Opis:
The problem of effective gas extraction from Polish shale rocks is an interesting research subject for scientists. A properly selected proppant, which protects cracks from closing during the fracturing process, inestimably contributes to an increase of extraction. Grains of proppant are transported along with a fracturing medium to reach the deepest regions of the crack. The proper support of the crack provides an easy flow of gas, therefore it is important in terms of extraction efficiency. This paper shows the interactions of a proppant grain with the crack surface in shale rock. FEM analysis was conducted to observe the stress region, which is generated as a result of pressing the grain into the crack surface. A model of a sphere which was pressed into the rock model with constant velocity was applied. The received results of stress depend on material properties and a range of proppant grain pressing.
Terytorium Polski od kilku lat jest obiektem wzmożonych badań mających na celu opracowanie opłacalnej technologii wydobycia gazu z łupków. Polskie skały łupkowe różnią się pod względem fizycznym i chemicznym od tych występujących w Ameryce Północnej, są rozlokowane również na innej głębokości. Inna budowa skały stawia zatem nowe wyzwania dla wiertnictwa otworowego. Procesy szczelinowania zachodzą w nieco inny sposób, zatem konieczne jest opracowanie nowej technologii wydobycia. Jednym z ważniejszych aspektów tych badań jest dokładna analiza zachowania się skały obciążonej ciśnieniem szczelinowania. Do rozważenia jest tu mechanizm powstawania i propagacji pęknięcia oraz optymalny sposób podparcia szczeliny po zabiegu szczelinowania. Tę funkcję mają pełnić proppanty, które dostają się do złoża wraz z czynnikiem szczelinującym. Ziarenka, najczęściej ceramiczne o dużej twardości mają za zadanie zaklinować się w skale, aby utworzyć maksymalne rozwarcie szczeliny. Oczywiście, przy ogromnych naprężeniach wewnętrznych górotworu nastepuje wgniatanie ziaren w powierzchnię skały, co powoduje zmniejszenie przekroju poprzecznego szczeliny, a w skrajnych przypadkach może prowadzić do całkowitego zamknięcia szczeliny. Do analizy MES opracowano model geometryczny. Przyjęto, że model skały to czwarta część walca ze szczeliną w środkowej częćci o promieniu 1 mm. Wygenerowano model skały łupkowej o promieniu 8 mm oraz długości 10 mm. Analogicznie do modelu skały, przyjęto ziarenko proppantu jako 1/4 kuli. Dyskretyzację modelu przeprowadzono w oprogramowaniu LS – PrePost za pomocą elementów ośmiowęzłowych. Utworzony model składa się z 29554 elementów oraz 60696 węzłów.
Źródło:
Archives of Civil Engineering; 2018, 64, 2; 55-65
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on heat flow in granite sample using thermal imaging camera
Autorzy:
Małek, E.
Miedzińska, D.
Niezgoda, T.
Stankiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/242569.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
thermovision
thermal imaging camera
temperature distribution
granite
aluminum foam sample
heat flow
Opis:
Research on heat flow in granite sample and sample of aluminium foam with the use of a thermal imaging camera is presented in the paper. Temperature distribution on the surface of the sample as a function of time was obtained on the basis of data from the thermal imaging camera. Thermovision is one of the most universal technology, which is applied for detection of infrared radiation. This technique allows observing and record infrared radiation emitted by objects located in the surrounding environment. This technology allows obtaining, in a short time, temperature distribution on the surface of the sample. The thermograms (pictures showing on the surface of the object) are types of photos showing temperature distribution on the tested object surface which is achieved on the base of a specified range of electromagnetic radiation. Accurate measurement of the temperature distribution on the heated granite sample surface was obtained using a thermal imaging camera FLIR SC 6000. Thermal imaging camera was connected to the computer equipped with control software FLIR ResearchIR Max. Heat source was applied in the experiment as a cast iron hotplate with high efficiency heating, gradual control and 1500W power. Obtained results showed regular temperature distribution over the surface of researched sample.
Źródło:
Journal of KONES; 2016, 23, 4; 327-333
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania eksperymentalne wpływu dwutlenku węgla na strukturę porowatą i właściwości mechaniczne skały łupkowej
Experimental study on influence of carbon dioxide on porous structure and mechanical properties of shale rock
Autorzy:
Miedzińska, D.
Powiązania:
https://bibliotekanauki.pl/articles/210249.pdf
Data publikacji:
2017
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
geomechanika
skały łupkowe
dwutlenek węgla
geomechanics
shale rock
carbon dioxide
Opis:
Skały łupkowe są formacjami geologicznymi, może w nich występować materia organiczna, dzięki której mogą powstać niekonwencjonalne złoża gazu. Podczas ich interakcji z dwutlenkiem węgla, który może być stosowany jako czynnik szczelinujący do wydobycia gazu, zachodzi wiele zjawisk mających wpływ na strukturę i parametry wytrzymałościowe skały. W pracy przedstawiono badania zmian struktury skały łupkowej pod wpływem oddziaływania dwutlenku węgla w stanie nadkrytycznym oraz ich wpływ na właściwości wytrzymałościowe skały. Badania strukturalne zostały przeprowadzone przy użyciu technik mikroskopowych przy różnych powiększeniach obrazu. Jako test właściwości wytrzymałościowych przyjęto próbę jednoosiowego ściskania. W wyniku prac zaobserwowano pewną zależność. Im bardziej zmniejszyła się porowatość badanej próbki po infiltracji dwutlenkiem węgla w małych powiększeniach, tym bardziej zwiększyła się jej porowatość w dużych powiększeniach i tym mniejszą osiągnęła wytrzymałość na jednoosiowe ściskanie.
Shale rocks are geological formations which can be unconventional gas reservoirs. During their interaction with carbon dioxide, which can be used as a fracturing fluid in shale gas recovery process, many phenomena take place that can influence rock structure and mechanical properties. The research on changes in rock structure under super critical carbon dioxide interaction and their influence of shale properties were presented in the paper. The structural tests were carried out with the use of microscopic techniques with different resolutions of visualization. The uniaxial compression test was applied as a mechanical properties’ assessment experiment. As a result of research, some dependence was observed. The bigger decrease was in porosity after infiltration in lower zooms, the bigger increase in porosity in high zooms and mechanical properties was noticed.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2017, 66, 4; 167-178
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Blast loading on aluminum foam microstructure
Autorzy:
Miedzińska, D.
Panowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/244041.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
microstructure
aluminium foam
strain rate effect
Opis:
One of the possible options as a material for protective layers is aluminum foams which become also very popular due to their lightweight and excellent plastic energy absorbing properties. Such characteristics have been appreciated by the automotive industry with continued research to further understand foam properties. Compressed foaming materials exhibit extensive plastic response, while the initial elastic region is limited in tension by a tensile brittle-failure stress. Aluminum foams have become also an attractive material as blast protective layers due to their desirable compressive properties. With different material engineering techniques (as, for example double-layer foam cladding) they can be customized to achieve the most desirable properties. Energy absorption capacity of foams microstructures under blast load was analytically confirmed based on a rigid-perfectly plastic-locking foam model Initial research indicates that energy absorbed by the cladding is much larger than that under quasi-static conditions due to strain rate effect. In this paper a numerical model of a closed cell aluminum foam idealistic microstructure was presented. The quasi static compression tests were carried out with the use of LS Dyna computer code. Then the sample was numerically loaded with the blast wavefrom detonation of explosives and its behavior was analyzed. The results ofboth analyses were compared.
Źródło:
Journal of KONES; 2010, 17, 3; 287-292
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CO2 - CH4 sorption induced swelling of gas shales: An experimental study on the Silurian shales from the Baltic Basin, Poland
Autorzy:
Miedzińska, D.
Lutyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/109897.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
shale rock
swelling
methane
carbon dioxide
sorption
Opis:
The main aim of the research presented in the paper was to study the phenomena of shale swelling induced by CH4 and CO2 sorption. In the study, a Silurian gas shale sample from the Baltic Basin in Poland was used. Samples represented typical characteristic features of polish shale gas formations with relatively low total organic carbon (0.8%) and high clay mineral content. The first part of the study was devoted to competitive adsorption of CO2 and CH4. The second part was devoted to observation of the sorption induced swelling phenomena, where sample linear strains were monitored with the use of strain gauges. Swelling tests were conducted up to the pressure of approximately 8 MPa with CO2, CH4 and helium as the baseline. Experimental results were compared with the Seidle and Huitt model where Langmuir constants where determined with volumetric sorption tests. Results of the study showed that matrix swelling in case of CO2 adsorption was greater than in the case of CH4 adsorption. The swelling value was directly proportional to adsorption and was about 5 to 10 times smaller than in the case of coal. Sorption of methane and carbon dioxide in the gas-bearing shale was about 10-times lower than in hard coals. The Seidle and Huitt model developed for coals was equally suitable to describe the processes of shale swelling.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 415-427
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and analytical research on resonance phenomena of vibrating head with MRE regulating element
Autorzy:
Miedzińska, D.
Gieleta, R.
Osiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/265035.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
vibratory pile hammer
resonance
vibrations
Fourier analysis
analiza Fouriera
wibracje
rezonans
Opis:
A vibratory pile hammer (VPH) is a mechanical device used to drive steel piles as well as tube piles into soil to provide foundation support for buildings or other structures. In order to increase the stability and the efficiency of the VPH work in the over-resonance frequency, a new VPH construction was developed at the Military University of Technology. The new VPH contains a system of counter-rotating eccentric weights, powered by hydraulic motors, and designed in such a way that horizontal vibrations cancel out, while vertical vibrations are transmitted into the pile. This system is suspended in the static parts by the adaptive variable stiffness pillows based on a smart material, magnetorheological elastomer (MRE), whose rheological and mechanical properties can be reversibly and rapidly controlled by an external magnetic field. The work presented in the paper is a part of the modified VPH construction design process. It concerns the experimental research on the vibrations during the piling process and the analytical analyses of the gained signal. The results will be applied in the VPH control system.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 1; 201-208
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research on influence of gas impact on thermal and mechanical properties of auxetic material covered with titanium silicide coating
Autorzy:
Miedzińska, D.
Gieleta, R.
Małek, E.
Zasada, D.
Stankiewicz, M.
Marszałek, K.
Powiązania:
https://bibliotekanauki.pl/articles/201182.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Ti-Si layers
damage
impact
thermal resistance
SEM
auxetic materials
Ti-Si
uszkodzenia
uderzenia
opór cieplny
materiały auksetyczne
Opis:
The aim of the presented work was to study the auxetic textiles covered with titanium silicide coating. The research was carried out to develop the material structure, which will be used for protective clothing, e.g. for firemen. The new material should be characterized by increased heat resistance coupled with protection against gas pressure impact caused e.g. by gas installation damage. In the paper, an assessment of the change in heat resistance properties of a Ti-Si coated auxetic textile loaded with gas pressure impulse was carried out.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 2; 165-172
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Introduction to n-body simulation of magnetorheological elastomer (MRE) microstructure forming process
Autorzy:
Miedzińska, D.
Łazowski, J.
Boczkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/246185.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
magnetorheological elastomer
n-body problem
magnetic interactions
smart materials
forming process
Opis:
Magnetorheological elastomers (MREs) are the materials with rheological properties which can be changed in a continuous way, rapidly and reversibly by the applied magnetic field. They are the solid analogues of magnetorheological fluids (MRFs), consisting of magnetically permeable particles (such as iron) added to a viscoelastic polymeric material prior to crosslinking. In the paper the introduction to the n-body simulation of the MRE microstructure forming process is presented. First, the basics of the n-body problem are presented as the planar three-body problem. It is well known, that the planar three-body problem is the problem describing the motion of three point masses in the plane under their mutual Newtonian gravitation. In the paper it is shown how that problem will be applied to the simulation of the phenomena that appeared when the external magnetic field is applied to the chaotically mixed iron particles in the liquid elastomer. Also the physical model of the interactions occurred in such structures are described. The assumptions shown in the paper will be then used for the development of the computer program which calculates the interactions between iron dipoles and describes the movement of the particles in the liquid elastomer under the magnetic field.
Źródło:
Journal of KONES; 2010, 17, 1; 249-253
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of CO2 acquisition and costs reduction in shale rocks fracturing technology
Autorzy:
Miedzińska, D.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/299042.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
fracturing
shale gas
carbon dioxide
economics
Opis:
The innovative method of shale gas recovery with the use of subcritical CO2 is currently developed within the project titled “Development of guidelines for design of innovative technology of shale gas recovery with the use of liquid CO2 on the base of numerical and experimental research – DIOX4SHELL ”, supported by the National Centre for Research and Development (NCBR). The project is carried out by Polish company PGNiG and by academics from WAT, AGH and PW (Military University of Technology, AGH University of Science and Technology, and Warsaw University of Technology). Finding the best business model, in which costs of CO2 production or acquisition are negligible is one of the most important factors influencing the economical effectiveness of the technology. The main part of known CO2 acquisition methods is based on fuel purchase and its combustion, what is very expensive process. It results with the high CO2 price, when purchasing from producer, about 300 zl/ton. This price is quite high, considering current low prices of natural gas. In the paper basic aspects of CO2 acquisition from CO2 producers, exhaust gases treatment plants or plasma gasification methods will be presented.
Źródło:
AGH Drilling, Oil, Gas; 2016, 33, 1; 11-22
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical calculations of RVE dimensions for two-phase material
Autorzy:
Miedzińska, D.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/242298.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
microstructure
two-phase material
metal-ceramic composite
RVE
Opis:
A representative volume element (RVE) is a statistical representation of typical material properties. It should contain enough information on the microstructure thereby be sufficiently smaller than the macroscopic structural dimensions. The paper deals with the numerical calculations of the dimensions of the RVE for a two-phase material microstructure. Two and three dimensional models are taken into consideration. The structure of the samples are developed on the base of randomization of elements belonging to one of the phases. The phases volume share is 50/50%. The following series of the models are analyzed: from 10 x 10 to 100 x 100 elements for 2D samples and from 10 x 10 x 10 to 100 x 100 x 100 elements for 3D samples. The element characteristic dimension is 10 jm. The elastic behavior of the base materials (magnesium and alumina) is taken into account. The quasi-static compression tests of the developed structures are carried out with the use of LS-DYNA computer code. The results are presented as the equivalent Young modulus values and compared to the calculations based on the rule of mixtures. The stabilization of the achieved results allows to assess the dimensions of the RVE for two-phase material with random distribution.
Źródło:
Journal of KONES; 2011, 18, 2; 303-310
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical modelling of the foamed materials structures with the usage of the 2D and beam elements
Autorzy:
Miedzińska, D.
Szymczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/245977.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
foamed aluminium
microstructure
FE modelling
Kelvin structure
Opis:
The possible options as materials for protective layers are aluminium foams which become also very popular due to their lightweight and excellent plastic energy absorbing properties. Such characteristics have been appreciated by the automotive industry with continued research to further understandfoam properties. Compressed foaming materials exhibit extensive plastic response, while the initial elastic region is limited in tension by a tensile brittle-failure stress. Aluminium foams have become an attractive material as blast protective layers due to their desirable compressive properties. With different material engineering techniques (as, for example double-layer foam cladding) they can be customized to achieve the most desirable properties. Energy absorption capacity of foams under blast load was analytically confirmed based on a rigid-perfectly plastic-locking foam model. Initial research indicates that energy absorbed by the cladding is much larger than that under quasi-static conditions due to shock wave effect. The methods of numerical modellingfor open and closed cell aluminium foams arepresented in the paper. The numerical models of foam ideal microstructures created with shell and together shell and beam finite elements are shown. The models were developed on the basis of Kelvin tetrakaidecahedrons - structures consisting of six sąuares and eight hexagons. In the case of open cell foams the circle wholes were removed from polyhedron surfaces. Then the numerical analysis o f a created models compressive test was carried out with the usage of MSC.Marc computer code. The nonlinear procedur es were applied. The results were analyzed in the scope of the assessing the behaviour of the open cell aluminium foam unit cell under the compressive load.
Źródło:
Journal of KONES; 2010, 17, 1; 267-272
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of the beam made of magnetorheological elastomer bending in the magnetic field
Autorzy:
Miedzińska, D.
Sławiński, G.
Boczkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/245981.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
magnetorheological elastomer
smart materials
numerical modelling
magnetic field influence
Opis:
Magnetorheological elastomers (MREs) belong to the group of so-called smart materials, which respond to an external stimulus by changing their viscoelastic properties. Magnetorheological (MR) material can be fluid, gel or solid like material, such as elastomer. The mechanical properties of the MR materials change when subjected to an external magnetic field. The MREs are interesting candidates for the active stiffness and vibration control of structural systems. In the paper the verification process of the applied FE modelling method is presented. The verification is based on the three point bending experiment. The results of that experiment were used to evaluation of the correction on numerical model and analysis. The model was based on the assumption that MRE behaves like an orthotropic material with the material properties o f MRE on the direction along the iron chains - and of a pure elastomer - on the other directions. Such an assumption can be made for the small deformations of a sample, what took place in the considered experiment. The FE modelling method was considered to be correct. On the base of the verified method a FE element model of the MRE beam bending was developed. Such MRE beams are used as "smart" switches that react under the changeable magnetic field.
Źródło:
Journal of KONES; 2010, 17, 1; 261-265
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical study on closed cell foam structure damage mechanisms
Autorzy:
Miedzińska, D.
Powiązania:
https://bibliotekanauki.pl/articles/246654.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
closed cell foam
finite element method
X-ray tomography
damage
Opis:
Metallic foams are currently being looked at as a new material for automobiles. The main goal of the use of metallic foams in vehicles is to increase sound dampening, reduce the weight of the automobile, and increase energy absorption in case of crashes, or in military applications, to combat the concussive force of IEDs. The metallic foams that are being looked at currently, are aluminum and its alloys due to their low density (0.4-0.9 g/cm3). In addition these foams have a high stiffness, are fire resistant, do not give off toxic fumes, are fully recyclable, have high energy absorbance, have low thermal conductivity, have low magnetic permeability, and are efficient at sound dampening, especially in comparison to light weight hollow parts. In addition, partial addition of metallic foams in hollow parts of the car will decrease weakness points usually associated with car crashes and noisy vibrations. These foams are cheap to cast by using powder metallurgy (as compared to casting of other hollow parts). The aim of the research was to describe and to assess the main mechanisms that appear in the foam structure during the compression. The development process of the finite element model of the closed cell foam microstructure is presented in the paper. The model geometry was based on the real structure research, which was carried out with the use of computed tomography. The model was built with the use of a unique computer code created to transform the scan point cloud into FE raster model based on solid 8-node elements. The experimental and numerical compression test results were compared and showed good compatibility. The stress distributions were studied to describe the main mechanisms in the structure.
Źródło:
Journal of KONES; 2012, 19, 2; 321-327
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 32

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies