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


Wyświetlanie 1-8 z 8
Tytuł:
Aluminium foam testing for impact energy absorption aims
Autorzy:
Niezgoda, T.
Miedzińska, D.
Powiązania:
https://bibliotekanauki.pl/articles/245628.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
aluminium foam
microstructure modelling
open cell foam
closed cell foam
Opis:
Aluminium foams are a new group of materials used for impact energy absorbing elements. They are light (typically 10-25% of the density of the metal they are made of) and stiff, and are frequently proposed as a light weight structural material. That is why they often are applied in automotive and transport industry solutions, for example as parts of bumpers. The methods of numerical modelling for open and closed cell aluminium foams are presented in the paper as well as closed and open cellfoam microstructure model. The numerical models of foam ideal microstructures created with shell finite elements are shown. The models were developed on the basis of Kefain tetrakaidecahedrons - structures consisting of six squares and eight hexagons. In the case of closed cell foams, the polyhedron with full walls was adopted. In the case of open cell foams the circle wholes were removed from polyhedron surfaces. Then the numerical analysis of a created models compressive test was carried out with the usage of LS Dyna computer code. The nonlinear procedures were applied. The results were analyzed in the scope of energy absorbing properties of aluminium foams.
Źródło:
Journal of KONES; 2009, 16, 3; 283-289
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
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:
New method of carbon dioxide underground storage coupled with shale gas recovery
Autorzy:
Niezgoda, T.
Miedzińska, D.
Kędzierski, P.
Powiązania:
https://bibliotekanauki.pl/articles/246774.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
shale gas
carbon dioxide
storage system
Opis:
Shale gas is natural gas produced from shale, a type of sedimentary rock. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in Canada, Europe, Asia, and Australia. One analyst expects shale gas to supply as much as half the natural gas production in North America by 2020. As of 2010, Poland imports two-thirds of its natural gas from Russia. ConocoPhillips has announced plans to explore for shale gas in Poland, along with Lane energy. The recently made available US Department of Energy report revealed that the largest reserves of shale gas in Europe are in Poland. The authors of the report calculate that Poland has reserves of about 22.45 trillion cubic meters of shale gas, of which 5.30 trillion cubic meters is immediately available for extracting. The most common method of shale gas recovery is hydraulic fracturing - the propagation of fractures in a rock layer caused by the presence of a pressurized fluid. Hydraulic fractures form naturally, as in the case of veins or dikes, and is one means by which gas and petroleum from source rocks may migrate to reservoir rocks. This process is used to release petroleum, natural gas (including shale gas, tight gas and coal seam gas), or other substances for extraction, via a technique called induced hydraulic fracturing. The method is critically assessed by ecologists. The paper deals with new method of gas shale fracturing and gas recovery coupled with carbon dioxide storage. It allows to effectively mine the shale gas and to store carbon dioxide in shale rock. It must be noticed that CO2 pollution is a very important problem in Poland, because of European Union CO2 limits. Also the numerical calculation of carbon dioxide thermodynamical process of decompression process, which simulates the injection of the cold liquid gas into the shale formation (high temperature and pressure conditions) and its influence on shale rock fracturing will be presented.
Źródło:
Journal of KONES; 2012, 19, 3; 327-333
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Various approaches to magnetorheological elastomers structures FE modelling
Autorzy:
Miedzińska, D.
Niezgoda, T.
Boczkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/245985.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
magnetorheological elastomer
FE modelling
multistage modelling
microscale
macro scale
Opis:
Magnetorheological elastomers (MREs) are the materials with rheological properties which can be rapidly and reversibly changed in a continuous way 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 different approaches to numerical modelling of the magnetorheological elastomers (MREs) structures are presented. The methods of the MRE micro- and macrostructural FE simulations are taken into consideration. The first approach is connected with the microstructural behaviour of the iron particles situated in the pure elastomer and subjected to the mechanical or magnetic load. The second approach is related to global material properties consideration and macrostructural behaviour modelling. The paper shows that there are many ways of such new materials structure behaviour modelling. All the FE analyses always need to be verified with the experiments as well as for macro- and micro scale material reactions, properties and phenomena describing.
Źródło:
Journal of KONES; 2010, 17, 1; 255-260
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Validation studies of the simplified model of the missile with cumulative head
Autorzy:
Sybilski, K.
Panowicz, R.
Kołodziejczyk, D.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/246839.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
RPG
simulation
FEM analysis
safety
slat armour
rod armour
Opis:
During ongoing conflicts around the world, some of the most dangerous threats are rocket-propelled grenades. They are light, easy to use and cheap, and their penetration reaches 900 mm of armoured RHA steel. Therefore, in many experimental and numerical laboratories there are researches of different, in aspect of shape, dimensions and used material, types of rod armours protecting against such a threat carried out. This kind of research must be confirmed in the last part of design by appropriate field tests. However, at the beginning of the design process, it is important to find a fast method of testing the developed solutions in a manner, which allows us to observe and measure as many process parameters as possible. One of such tests is research with the use of simplified models built in an appropriate scale. Small dimensions and simple construction result in the fact that the cost of manufacturing of models is much lower, and time is shorter. Tests on the simplified models are also possible to be carried out in laboratory conditions, what reduces the costs and makes the measurements of physical properties easier. The article describes experimental investigations of the impact of a simplified missile with a shape charge jet head model into a thick plate and steel rods. The construction of a missile, the used equipment and apparatus as well as the proceedings of the experiment are presented. The paper provides information about the structure of FE model and both initial and boundary conditions of the examined system. The results of numerical analysis are presented and compared with the results from experimental tests.
Źródło:
Journal of KONES; 2012, 19, 3; 415-420
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
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:
Influence of the volume fraction of the carbonyl iron particles on the mechanical properties of the magnetorheological elastomers
Autorzy:
Sławiński, G.
Niezgoda, T.
Miedzińska, D.
Gieleta, R.
Powiązania:
https://bibliotekanauki.pl/articles/247437.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
smart materials
magnetorheological elastomer (MRE)
finite element method (FEM)
Opis:
Magnetorheological materials belong to the group of the so called intelligent materials. Their rheological properties can be changed in a large range using an external magnetic field. That is why they fmd ever growing application in modern technical equipment, among others in controlled dampers, clutches, sensors etc. In the paper, a numerical strength analysis of a magnetorheological material was presented. The influence of the volume fraction of carbonyl iron particles (the share of the carbonyl iron particles varied from 1.5 to 33.0 vol. %.) on the mechanical properties of the material were investigated, in particular on the Young's modulus variation. Experimental tests were carried out for specimens made of pure PU 70/30 elastomer with iron particles. They induded uniaxial compression tests. In the farmer case, specimens were in a shape of a cylinder with a diameter of 20 mm and a height of 25-30 mm. The results of experimental tests carried out in order to determine the parameters necessary to build the numerical model were induded in the paper. In the paper, an algorithm developed for determining the parameters for modelling the structure was presented. A fragment of the structure, containing several particles of iron and some quantity of elastomer, corresponding to the assumed volume fractions, was subjected to numerical analysis.
Źródło:
Journal of KONES; 2010, 17, 3; 401-406
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
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
    Wyświetlanie 1-8 z 8

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