Wszystkie pola: Miedzińska, D. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

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

Zmień widok

na półce

Skocz do pozycji: 2.

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

Zmień widok

na półce

Skocz do pozycji: 3.

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

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: Numerical analysis of an open cell foam structure with the use of models based on 2D finite elements
Autorzy:: Szymczyk, W.
Miedzińska, D.
Powiązania:: https://bibliotekanauki.pl/articles/242137.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: FEM modelling
open cell foam structure
effective properties
Opis:: The paper deals with the numerical analysis of foam materials. Open cell foam is investigated. Numerical simulations allow calculating modes of destruction and assessing effective properties of the model structures. Metal as well as polyurethane foams show out interesting properties. They are light, have good acoustic and/or magnetic isolation, have ability to absorb energy of vibration and hits. They are used for sandwich panels, hit absorber s (i.e. as elements of buffer constructions in rail vehicles),fillers of construction parts, bodies of vehicles (i.e. floating combat vehicles), dividing walls on vessels and others. Specially prepared open cell foams show out auxetic properties and shape memory effect. Such materials are very good for seats in aircrafts which may protect pilots and passengers during crashes and restrict heavy backbone injuries. Foams are used for filtering purposes. Foams themselves or in combination with different types of fillers (i.e. elastomers) or ceramic reinforcement may be used for hit energy absorbing panels for military purposes (protection against explosion shock wave and splinters). Presented work is a part of a series of numerical experiments which aim is to investigate the influence of geometry parameters onto effective properties of the foam. Different types of geometries are used for numerical experiments. All the models of single foam cell are based on Kelvin grain geometry. Numerical compression tests performed with the use of models based on 2D finite elements provide studying the process of the structure failure. Effective characteristics of investigated foams show out that such materials would be useful for energy absorbing purposes.
Źródło:: Journal of KONES; 2009, 16, 2; 441-448
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Numerical investigations on vibrating motion with inertial load of vibratory pile hammer stiffly coupled with excavator
Autorzy:: Osiński, J.
Miedzińska, D.
Powiązania:: https://bibliotekanauki.pl/articles/247648.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: elastomer
vibrations
simulation
resonance
numerical analysis
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 in 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), which 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 development of the numerical model of the VPH and soil interaction that will describe resonance conditions, resonance frequencies with consideration of soil susceptibility, coupling phenomenon and elastomer changeable stiffness. On the base of developed theoretical equations, the frequency of VPH piling will be regulated to assure the over-resonance work.
Źródło:: Journal of KONES; 2014, 21, 1; 189-195
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: Failure analysis of chosen 3D numerical models of an open cell foam
Autorzy:: Szymczyk, W.
Miedzińska, D.
Powiązania:: https://bibliotekanauki.pl/articles/243845.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: FEM modelling
open cell foam structure
Opis:: Metal and polyurethane foams exhibit interesting properties. They are light, have good acoustic and/or magnetic isolation as well as ability to absorb the vibration and impact energy. They are used for sandwich panels, impact absorbers (i.e. as elements of the buffer constructions in rail vehicles), fillers ofconstruction parts, bodies of vehicles (i.e. floating combat vehicles) and for dividing walls of vessels and others. Speciflcally made open cell foams demonstrate auxetic properties and the shape memory effect. Such materials are very good for seats in aircrafts which may protect pilots and passengers during crashes and limit heavy backbone injuries. Foams are used for filtering purposes. Foams or their in combination with different types of fillers (i.e. elastomers) or the ceramic reinforcement may be used in impact energy absorbing panels for military aim (protection against an explosion shock wave and splinters). In the paper aluminium open-cell foam structures were investigated for their energy absorption ability. For this purpose a series of numerical 3D models were applied. Geometry of the models was based on Kehin's polyhedrons. Tests of uniaxial compression were simulated with the use of LS-Dyna computer code. Complex contact phenomena were considered. Preliminary test were performed with the use of single foam cell models. Further simulations were conducted using 3x3x3 cell models. The results were analyzed as force/time characteristics.
Źródło:: Journal of KONES; 2010, 17, 1; 449-454
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Comparative study of hybrid foam microstructure models
Autorzy:: Szymczyk, W.
Miedzińska, D.
Powiązania:: https://bibliotekanauki.pl/articles/246261.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: FEM modelling
foam structure
elastomer filament
geometry orientation
Opis:: Cellular solids are materials made out of solid strut or thin plate like structures bridged together. They occur in nature in the form of honeycombs, wood, bone, cork etc. These materials possess a unique combination of properties such as low thermal conductivitv, low density and high energy-absorption. Foams are a class of cellular solids, generally made by dispersing gas into a liquid material and then cooling it to solidify. They are categorized as open-cell and closed-cell foams. Depending on the solid materials that are made into foams, they are also categorized as polymeric foams, metallic foams, and ceramic foams. Due to developments in material science and manufacturing lechniques, advanced foams have found potential for use in automobile, aircraft, and space vehicle structures. In the paper the comparative study of the hybrid foam microstructures is presented. Hybrid foam is a new, still developed material that is built of the aluminum open cell foam matrix filled with other material (here: elastomer). The numerical models based on cubic geometry in different configurations are developed. The FE analysis of the compression test is curried out. The results are presented and analyzed due to the microstructure geometry influence on the material behaviour.
Źródło:: Journal of KONES; 2010, 17, 4; 505-511
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

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

Zmień widok

na półce

Skocz do pozycji: 9.

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

Zmień widok

na półce

Skocz do pozycji: 10.

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

Zmień widok

na półce

Informacja

Wyszukujesz frazę "Miedzińska, D." wg kryterium: Wszystkie pola

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język