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Wyświetlanie 1-8 z 8
Tytuł:
Analysis of a light caterpillar vehicle loaded with blast wave from detonated IED
Autorzy:
Barnat, W.
Niezgoda, T.
Panowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/247638.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
IED
vehicle shell
FE analysis
ground
Opis:
More and more impudent attacks on the military convoys in Afghanistan proved a huge danger of the improvised explosive devices - IED. Huger and more clever charges are a serious problem for vehicles protection. Additionally, hitherto defence standards and STANAG didn't predict such huge charges. Majority investigations were based on a 3 kg anti-tank mine. The article presents the results of numerical calculations for the elements of the combat vehicle supporting structure loaded with an impact generated by explosion of a huge explosive charge under the bottom of the vehicle with consideration of the wave reflected from the ground. Such an approach allows obtaining a good approximation of numerical simulations to real conditions of terroristic attacks. Additionally, the analysis of IED side influence on the vehicle shell was conducted. The explosive charge — IED — was simulated with the use of concentrated energy of properly selected (on the base of literature investigations) density and initial energy. During analyses of side explosive on the vehicle structure, the obstacle in the form of a building increasing the pressure impulse was taken into account. The paper presents the results of a numerical analysis in which Euler and Lagrange domains(describing a vehicle) were coupled. A perfect gas model was used to describe air parameters.. Additionally, the ground was described with a gas model. Every kind of material data were selected on the base of experimental investigations. A bilinear material model with a Cowper and Symonds strain rate model was used to describe a vehicle. Such an approach fully describes the phenomena occurring in the system.
Źródło:
Journal of KONES; 2010, 17, 4; 27-34
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of a panel with an elastomer layer plus carbon fibres loaded with a blast wave
Autorzy:
Barnat, W.
Niezgoda, T.
Gieleta, R.
Panowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/247636.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
blast wave
experiment
FE analysis
elastomer layer
Opis:
Terrorist attacks are directed against the most important elements of the infrastructure and human life. Crews of the combat vehicles as well as transmission installation of oil, gas and electric energy are, first of all, exposed to such operations. Such a situation caused striving to increase the safety against the activity of short-time loads coming from explosions [l, 2]. The object of the presented investigations was a numerical-experimental analysis of an elastomer layer of the protective panel combined with an experimental verification. Developed elastomer structures constitute perspective materials and will be applied to solve the problems connected with the increase of combat vehicle safety as well as trouble constructions of pipelines and gas pipelines especially in the dangerous places such as passages over rivers. A plate with an elastomer layer (with carbon fibres) loaded with a 100 g TNT charge was subjected to the analysis. The numerical analysis was verified experimentally. The results of the conducted analyses will be applied in further works on the selection of the kinds and parameters of the energy absorbing layers. They will be also used for further validating and optimizing investigations, which will aim at absorbing or dispersion of a maximum great value of energy influencing the energy absorbing panel. Such panels can be used for constructing armoured vehicles and protective elements of stationary strategic constructions. The constructions which can be exposed to damages resulted from a different kind of dynamic forces such as impacts or influences of the pressure wave comingfrom detonation of an explosive material should have the structure enabling absorption of as great as possible part of energy which influences them. Energy absorbing elements are constructed in the form of sandwich structures coats with a specially selected core material. One of the interesting types of materials which can be used for this purpose is elastomer. These materials enable significant increasing of the protective degree due to their capacities of absorbing energy of a blast wave. Applying of these materials results in decreasing of vibrations frequency of a system loaded with a pressure impulse.
Źródło:
Journal of KONES; 2010, 17, 4; 19-26
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of a protective composite panel with energy adsorbent in the form of foamed aluminium
Autorzy:
Barnat, W.
Panowicz, R.
Niezgoda, T.
Gieleta, R.
Powiązania:
https://bibliotekanauki.pl/articles/247656.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
blast wave
analytical model
FE analysis
aluminium panel
Opis:
The article presents the results of the investigations into modelling a blast wave for huge charges of l kg TNT equivalent. Modelling of huge charges is a very interesting problem due to a scale effect. During numerical analyses a detonation phenomenon was ignored (for the reason of the analysis time). The paper considers the effects of the influence of a pressure wave coming from a huge TNT charge (modelled with energy) on a 6 mm thick steel plate as well as on a protective panel made of foamed aluminium with composite layer. A panel of foamed aluminium was used for the protection of the described plate. The particular elements of a panel, subjected to an experimental analysis, were jointed with the use of a glueing method. In the numerical model the particular component layers were jointed with contact. The ALE (Arbitrary-Lagrange-Euler) function was used for coupling between the Euler domain and the Lagrange domain. The method requires absolute location compatibility of the nodes from both jointed areas. In the results of the conducted investigations, the permanent deformation of the steel plate was obtained.. Additionally, the possibility of the steel plate deformation evaluation was considered on the basis of accessible literature. Due to a huge charge, the analysis was performed with the use of the finite element method with the eiperimental verification.
Źródło:
Journal of KONES; 2010, 17, 4; 35-44
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CI engine as a case study of thermomechanical FE analysis of the piston - piston rings - cylinder system
Autorzy:
Szurgott, P.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/247997.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
engine piston
composite piston
thermomechanical analysis
FE analysis
Opis:
The compression-ignition engine as a case study of a methodology of the numerical modelling and simulation of the piston - piston rings - cylinder system was presented in the paper. Thermomechanical FE analysis, taking into account thermal and mechanical loads, was carried out using the MSC.Marc/Mentat software. The mechanical loads included loads due to inertial and gas forces as well. A three dimensional solid geometrical model of the considered set was developed using AutoCAD software, whereas the finite element mesh was generated using Altair HyperMesh. Kinematic boundary conditions - the vertical displacement and acceleration of the piston - were described by the corresponding curves as a function of time for selected engine speed. Changes in pressure on the piston crown were estimated based on data from the engine manufacturer and the corresponded indicator diagram available in the literature. The results of thermomechanical FE analysis were presented in the form of stress and/or displacement contours. The main aim of the analysis was to determine the deformation of the piston depending of on the piston material. Two types of material were compared - the actual one PA12 aluminum alloy and the new composite material with low hysteresis. The second material was characterized by slight differences of the coefficient of thermal expansion for heating and cooling.
Źródło:
Journal of KONES; 2012, 19, 1; 399-406
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:
Thermomechanical FE analysis of the engine piston made of composite material with low histeresis
Autorzy:
Szurgott, P.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/244407.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
engine piston
composite piston
coefficient of thermal expansion
thermal analysis
FE analysis
Opis:
The main purpose of the preliminary analyses presented in the paper was to compare the behaviour of the combustion engine piston made of different type of materials under thermal load. A thermomechanical FE analysis of the engine piston made of composite material was shown. A selected engine is installed in one of the popular polish tanks. The proposed new material is characterized by a low hysteresis – the differences of the coefficient of thermal expansion for heating and cooling are not significant. The results obtained for the piston made of a new material were compared with those for the current standard material. The piston was loaded by a temperature field inside it. Appropriate averaged thermal boundary conditions such as temperatures and heat fluxes were set on different surfaces of the FE model. FE analyses were carried out using MSC.Marc software. Development of the FE model was also presented. Geometrical CAD model of the piston was developed based on the actual engine piston, which was scanned using a 3D laser scanner. A cloud of points obtained from the scanner was processed and converted into a 3- dimensional solid model. FE model of a quarter part of the piston was developed for the preliminary analysis presented in the paper. 4-node tetrahedron finite elements were applied since there was no axial symmetry of the considered object. The temperature field inside the piston was determined and presented in the form of contour bands. Contours of displacement and stress in a radial direction were shown as well.
Źródło:
Journal of KONES; 2011, 18, 1; 645-650
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of the influence of a rigid obstacle on the multiple reflected pressure impulse
Autorzy:
Barnat, W.
Panowicz, R.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/247658.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
pressure impulse
analytical model
FE analysis
influence of the obstacle on the reflected wave
Opis:
The article presents the case of multiple reflection ofa blast wave from a rigid obstacle. The pressure impulse was generated in the Euler domain according to Taylor-Sedov theory. Additionally, there the results of numerical and analytical investigations on the behaviour of the reflected pressure impulse from the flat stiff obstacle were discussed. The analytical considerations are pursuant to the accessible literature. This case is identical with the explosion under a flat bottom of the tank-type vehicle or BWP. All the considered obstacles which are influence by the pressure impulse are similar to the construction of the vehicles used by Polish Army. As it was mentioned above, the numerical investigations were supported by analytical modelsfrom the scientific literature. In the previous papers, the authors conducted the numerical and experimental investigations on the flat blast wave. Those papers concentrated on the selection of the Euler domain parameters and parameters describing an explosive charge for numerical analyses. Additionally, the parameters of the boundary elements of the Euler domain were selected in order to unable the uncontrolled influence of gases. The innovation presented in the paper is the description of the issue of the numerical problem of multiple pressure impulse reflection from a rigid obstacle. The presented papers aim at increasing the safety of the military vehicles crews during the stabilisation missions in Iraq and Afghanistan.
Źródło:
Journal of KONES; 2010, 17, 4; 45-54
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FE numerical tests of railway wagon for intermodal transport according to PN-EU standards
Autorzy:
Krason, W.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/202087.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
prototype railway wagon for intermodal transport
FE methodology of numerical tests
analysis of the wagon strength and dynamics simulations according to PN-EU standards
prototyp wagonu kolejowego transportu intermodalnego
FE
metodologia testów numerycznych
analiza wytrzymałości wagonu
symulacja dynamiki wagonu
normy PN-EN
Opis:
A special wagon, presented in the paper, can be used for intermodal transport of various types of vehicles. It enables transport of vehicles of 36 tons mass and height of 4m on the GB1 clearance height. An innovative wagon is equipped with a frame-support with marginal parts mounted on standard biaxial bogies and the central part lowered with a rotatable loading platform. The rotating part of wagon acts as a kind of platform, allowing truck to move through it during load/unload. During railway operation, this rotating platform is to become an integrated part of the wagon; the tailboards of the rotating part will be connected to the over-bogie part with the special locks. A unique concept of the wagon structure forced a design approach which was rather unusual for the rail industry. Since the design team aimed at very challenging demands of GB1 envelope and usage of standard bogies, the layout of the wagon had to be thoroughly examined in terms of its overall stiffness. Every major design change had to be simulated in order to accurately predict its influence on the whole wagon structure. FE analysis was used for numerical tests of such a wagon structure in different configurations. The calculations were carried out on the basis of PN-EN standards. Selected results of numerical tests of the prototype version of a such wagon for intermodal transports were presented in the paper.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 4; 843-851
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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