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Wyświetlanie 1-11 z 11
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:
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:
Numerical and experimental study of real foam microstructure models
Autorzy:
Miedzińska, A.
Szymczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/246346.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
microstructure
aluminium foam
3D scanning
Opis:
Metal foams are new, as yet imperfectly characterized, class of materials with low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They offer a potential for lightweight structures, for energy absorption, and for thermal management; and at least some of them are cheap. Such characteristics have been appreciated by the automotive industry in the aspect of crash and impact phenomenon. Energy absorption capacity of foams under dynamic load was analytically confirmed based on a rigid-perfectly plastic-locking foam model. In this paper the development process of a real closed cell foam microstructure based on finite element model with the use of SD scanning is shown. Computed tomography (CT) is a medical imaging method employing tomography created by computer processing. Digital geometry processing is used to generale a three-dimensional image of the inside of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation. The numerical analyses carried out with the usage of LS Dyna computer code of the quasi static and dynamic compression tests are presented. The most important mechanisms and phenomena that appeared in the microstructural sample are described. In the final part of these investigations the comparison process between numerical and experimental test was performed. The results confirmed the good correspondence between both tests.
Źródło:
Journal of KONES; 2010, 17, 2; 309-314
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
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
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
Tytuł:
Numerical analysis of an open cell foam structure with the use of models based on solid finite elements
Autorzy:
Szymczyk, W.
Miedzińska, D.
Powiązania:
https://bibliotekanauki.pl/articles/245581.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 apart 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 solid 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, 3; 409-414
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Tytuł:
Polymers foam structure numerical identification
Autorzy:
Rumianek, P.
Żach, P
Powiązania:
https://bibliotekanauki.pl/articles/248077.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
elastomers
polymers foam
oscillation
very large reversible deformation
Opis:
Polymers found regard among engineers and researcher their special proprieties. Now, we find using the polymers at present in the most advanced technically the branches of industry. In construction of machines, more and more often are practical used hyperdeform materials. The group of construction materials, called hyperdeformable, includes among others: elastomers, plastics made based on rubber, thermoplastic structures, such as polycarbonate, gels and sols, composites and foams: open and closed pores. Porous structures are produced on the basis of different materials, synthetic thermoplastic polymers and thermosetting. The problem of porous materials is taken in many research centres in the world. Porous materials (also called cellular plastics, foam plastics or foamed plastics) include gas phase dispersed in a solid phase of polymeric material. Properties of such systems depend on the properties of the polymer warp and cell structure comprising the gas phase. Approach previously used to anticipate and interpret the behaviour of the hyperdeformable structures, using the theory of hyperelastic materials, does not resolve the issue because it only describes the elastic properties. The article presents an original methodology developed structural identification the viscoelastic properties of hyperdeformable materials, and in particular modern construction materials from the group of plastics and composites of elastomers, foams, etc
Źródło:
Journal of KONES; 2014, 21, 3; 259-263
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
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:
Modelling and numerical simulation of the protectiye shield - protected plate - test stand system under blast shock wave
Autorzy:
Klasztorny, M.
Dziewulski, P.
Niezgoda, T.
Morka, A.
Powiązania:
https://bibliotekanauki.pl/articles/242616.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
light armoured vehicle
protective shield
aluminium-hybrid laminate-foam shield
blast shock wave
modelling and simulation
Opis:
The study presents FE modelling and simulation of a system for range testing of protective shields for light armoured vehicles. The protective shield designed by Authors is used against HE mines and IEDs up to 10 kg TNT. The system consists of the multiple-use portable rangę stand, a protected Armox 500T steel plate and a protective shield. The shield has a multi-layer structure and has the following main layers: PA11 aluminum, SCACS hybrid laminate, ALPORAS aluminum foam, SCACS hybrid laminate, connected together using SOUDASEAL chemo-set glue. The HE spherical charge is suspended centrally at 400 mm distance from the top surface of the stand. Overall dimensions of the test stand are approximately 800x800x180 mm, the protected piąte has dimensions 650x650x5 mm, and the protective shield is of 450x450x76 mm dimensions. The system is supported by an additional steel plate stiffening the subsoil. FE modelling, numerical simulations and processing the results were performed for the system under blast shock wave using the following CAE systems: CATIA, HyperMesh, LS-Dyna, and LS-PrePost. The 8-nodes brick finite elements were used, taking into account friction and contact phenomena. Isotropic and orthotropic material models and advanced nonlinear equations-of-state for some parts of the system were chosen, with relevant failure and erosion criteria, including the Johnson — Cook model for Armox 500T steel and PA11 aluminum and the MAT 161 model for plies of hybrid laminates. The shock wave was modelled approximately using the LOAD BLAST ENHANCED option available in LS-Dyna Version 971 R4 Beta code. Numerical simulations were performed for 2 kg TNT.
Źródło:
Journal of KONES; 2010, 17, 3; 197-204
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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