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 "numerical" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 20
Tytuł:
Experimental validation of the numerical model of a car impact on a road barrier
Autorzy:
Barnat, W.
Bogusz, P.
Dziewulski, P.
Gieleta, R.
Kiczko, A.
Klasztorny, A.
Klasztorny, M.
Niezgoda, T.
Ochelski, S.
Powiązania:
https://bibliotekanauki.pl/articles/245936.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
car - road barrier system
crash test
experimental examinations
numerical simulations
numerical model validation
Opis:
This analysis considers the problem related to the transport safety improvement by applying specialized energy absorbing elements. The advanced finite element method was used to solve this problem. The obtained results permit to estimate the practical usability of the proposed solution. In previous works of the examination team [1-5] a series of numerical analysis of the car -- road barrier dynamical system, directed to the elaboration of the numerical model methodology of an impact problem with the use of chosen CAE programs, was submitted. In this article experimental results of a Suzuki Swift car impact into a standard road barrier arę presented. Tests were carried out at the Automotive Industry Institute (PIMOT) in Warsaw, with the use of a test sample of the road barrier. Presented results of experimental tests serve to validation of a numerical model of the aforementioned system. For the safety sake the car's speed during the experimental examinations was limited to 50 km/h. Moreover, the vehicle hit perpendicularly a properly modified road barrier's sector. Experimental initial boundary and constructional conditions were modelled in numerical examinations. in which a commonlv available Suzuki Swift car model, http://www.ncac.gwu.edu, was used. Numerical analysis was carried out with the use of LS-DYNA system.
Źródło:
Journal of KONES; 2010, 17, 1; 17-27
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental investigation of selected explosion parameters for numerical model
Autorzy:
Barnat, W.
Gieleta, R.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/241757.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
IED
improvised explosive device
numerical model
validation
Opis:
The aim of presented work is examination of blast wave, especially incident and reflected wave pressure. Due to many difficulties and complexity of phenomenon a complete study for different charges should be done. In presented paper two cylindrical TNT charges were used, weighting respectively 100 g and 200 g. Pressure wave was examined using original test stand designed and developed on Department of Mechanics and Applied Computer Science. A test steel test plate with 5 mm thickness was equipped with pressure gauge to measure reflected wave. Additionally, the plate was placed on four special electroresistance strain gauges...To measure force Vishay EA-06-120-060LZ strain gauges were used. For amplification of the dynamometers with strain gauges, MS1001 INFEL bridge was used. The system was used to validate the results from reflected wave pressure gauge. Shock wave pressures was measured using a special sensor model 137A21 amd M350B21 made by PCB Piezotronics At specific distance there was also incident wave pressure gauge. In order to fully examine the dynamic response of the plate an accelerometer was used. As a result, pressure versus time and acceleration versus time plots were obtained. The results will be used to validate numerical model of blast wave impact on a plate.
Źródło:
Journal of KONES; 2012, 19, 4; 9-13
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of a shaped rail pad under selected static load
Autorzy:
Szurgott, P.
Gotowicki, P.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/248000.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
numerical analysis
FEM
rail pad
hyperelastic material
fastening
Opis:
Numerical analysis of selected type of the polyurethane rail pad is presented in the paper. A shaped pad with cylindrical-shaped elements in its working section was selected as a representative for the computational simulation. Analysis reflected the experimental test according to the valid standard. The test included loading of the vertical force perpendicular to the foot of the rail. Such test allows determining the static stiffness of the pad. The Mooney - Rivlin material model was selected in the current study. Necessary experimental tests including a uniaxial compression and tension were conducted to provide material constants for the hyperelastic material model applied for the FE model. Simplified FE models of the considered rail pad and the rail were developed. Rounded corners and edges of the cylindrical-shaped elements were omitted, since their modelling required a significant density of the FE mesh. Vertical force perpendicular to the foot of the rail was declared as nodal force distributed evenly along the edges of the selected finite element models Non-linear static analysis was performed using MSC.Marc software with large displacements and deformations taken into consideration. The obtained results allowed estimating deformations and the state of stress in a highly deformed rail pad. The static stiffness of the pad was defined as secant stiffness based on the vertical force - deflection curve.
Źródło:
Journal of KONES; 2012, 19, 1; 407-414
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental-numerical analysis of steel - foam energy - absorbing panels for road barriers modernization
Autorzy:
Niezgoda, T.
Ochelski, S.
Klasztorny, M.
Barnat, W.
Kiczko, A.
Dziewulski, P.
Powiązania:
https://bibliotekanauki.pl/articles/246007.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
numerical simulations
road transport
road barriers
passive safety
Opis:
The works on steel -foam energy-absorbing structures for the road barrier W-beam guardrail were carried out because of the necessity of increasing the passive safety of road barriers [1-5]. A road barrier guardrail is made of steel sections. These types of sections are characterized by good strain properties, although their energy-absorbing abilities and possibilities for "softer" vehicle impact energy are unsatisfactory. In order to increase energy-absorption on the road barrier guardrail additional tin-foam sections were used. Experimental tests on the modifled road barrier guardrail were carried out on a testing machine INSTRON at the Faculty of Mechanics and Applied Informatics of the Military Academy of Technology. Two meters long W-beam guardrail was investigated in a three point bending test, perpendicularly and under the angle of 20°. As a result of the experimental research diagrams of dependence of bending force on displacement were obtained. On the basis of aforementioned diagrams the energy that was absorbed by individual road barrier elements: tin coating, foam insert and steel guardrail, was estimated. Obtained results of the experimental research were also compared with the results of the numerical simulation of the finite elements method in LS-DYNA system.
Źródło:
Journal of KONES; 2010, 17, 1; 309-315
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical model of bullet - barrel system
Model numeryczny układu lufa - pocisk
Autorzy:
Łazowski, J.
Małachowski, J.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/241651.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
lufa
pocisk
modelowanie numeryczne
barrel
bullet
numerical modelling
Opis:
Aktualnie, projektowanie uzbrojenia w dużej mierze opiera się na metodach analitycznych, które nie pozwalają na znaczną poprawę parametrów broni w zakresie odporności udarowej. Szczególnie istotna jest analiza dynamiki dla ruchu pocisku w lufie na stożku przejściowym i ustalenie optymalnych parametrów procesu. Na styku lufy i pocisku zachodzą bardzo złożone procesy termomechaniczne. Oddziaływanie to powoduje powstawanie na powierzchni styku ciał ciepła a w konsekwencji zmian właściwości mechanicznych. Dodatkowo charakter współpracy obu ciał obarczony jest często brakiem symetrii wynikającym między innymi z niedokładności wykonania elementów, nieodpowiednim osadzeniem pocisku w lufie oraz niejednorodnością materiałów. W skutek takiej złożoności zjawisk, której konsekwencją są np. zmienność współczynnika tarcia czy również drgania pocisku i lufy, ogólne analityczne wyznaczanie stanów naprężeń i stanów krytycznych w sposób ścisły jest niemożliwe. Jedyną skuteczną metodą może być w tym przypadku modelowanie numeryczne. W pracy przedstawiono próbę analizy stanu wytężenia powstającego podczas szybkozmiennych procesów w trakcie współpracy pocisku z lufą. Przedstawiono model numeryczny obiektów i zaprezentowano wyniki analizy w formie planów warstwicowych. Narzędziem zastosowanym do analizy był pakiet obliczeniowy LS-DYNA umożliwiający symulacje w zakresie nieliniowym z jawnym krokiem całkowania.
Currently the design process for armament equipment mostly employs very known and traditional analytical methods. But in many cases this kind of approach is not sufficient and effective, especially for gun parameters related with impact resistance. Very crucial for proper dynamic bullet movement in the barrel are geometric dimensions. In the contact areas between a bullet and a barrel appear some thermo-mechanical phenomena. Additionally, the cooperation process between these two components is encumbered because of the asymmetry caused by the inaccuracy of production process and the inhomogeneity of used materials. Finally, the mentioned reasons produce some unwanted effects like: bullet and barrel vibrations, problems with friction phenomena, etc. In such situations, the typical engineering approach in design process is unable to take into considerations all such local and very complex effects. Therefore, this paper presents is a trial of numerical methods application, which allow perform full analysis process of interaction between bullet and barrel. The models of these two bodies were developed using FE method. The numerical calculations were performed using LS-DYNA code. The main goal of the research was focused on contact problem. In the paper authors enclosed the initial results of the dynamic simulations.
Źródło:
Journal of KONES; 2007, 14, 1; 261-266
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of the influence of blast wave on human body
Autorzy:
Sławiński, G.
Niezgoda, T.
Barnat, W.
Wojtkowski, M
Powiązania:
https://bibliotekanauki.pl/articles/244503.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
improvised explosive devices
blast wave
survivability
numerical study
Opis:
Threats for military personnel during combat missions nowadays are of different sources. Further development of methods for neutralization of mines or improvised explosive devices (IED) explosions must be preceded by identification of the impact phenomenon on crew of the military vehicle. Large accelerations cause injury to a person located in the interior of the vehicle and may lead to permanent disability exempting soldiers from the battlefield. Information about overload coming from the explosion of IEDs on humans are difficult to access or not sufficiently detailed. Therefore, the basis for their acquisition is conducting experimental research and modelling. The paper is presents finite element analysis of blast wave effects on a human body simulated by a numerical 50th percentile HYBRID III dummy. Coupled Euler and Lagrange (ALE) formulations are used in the finite element analysis of such problems to accurately represent the detonation phenomenon. Numerical model was developed in LS-PrePost software. All the computational analyses were carried out using an explicit LS-DYNA solver on multiprocessor cluster. Data such as hip and knee moment of inertia, femoral force, and foot acceleration are collected from the numerical dummy, which simulates the occupant’s response. These data are then compared to injury threshold values from various references to assess survivability
Źródło:
Journal of KONES; 2013, 20, 3; 381-386
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of road barriers on their abilities to absorb energy of hitting
Autorzy:
Niezgoda, T.
Kiczko, A.
Barnat, W.
Dziewulski, P.
Powiązania:
https://bibliotekanauki.pl/articles/244885.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
numerical simulations
validation
road transport
road barriers
passive safety
Opis:
In the article, the results of tests and numerical computations of road infrastructure elements-protective barriers are presented. On the base of carried out tests (in laboratory conditions) the forms of deformations of each of elements and their assemblies, components of road protective barriers, were described. The determination of stiffness of each type of barriers, at the moment of their destruction, enabled to elaborate the methodology of the construction of numerical models and numerical simulations of the process of the barrier destruction. The absorption of energy of three subassemblies of road barriers, consisting of the W-beam guard rail section of 0.7 m, a post and SP01, SP05 and SP09 mounting hardware, was experimentally determined. From the comparison, the experimental results with the numerical simulation ones it is seen that proposed numerical models with a good accuracy present the behaviour of the real elements of barriers. Investigations enabled to estimate the distribution of absorbed energy of each constructional elements of barriers at the moment of their destruction. Further step in the investigation is to be an attempt to modify the construction, paying special attention to increasing its ability to absorb energy of collision. On this base, the protective road barrier system can be enriched with elements absorbing energy. Great energy absorbing abilities have elements which are subjected to progressive destruction e.g. by plastic deformation or delamination of elements produced from relatively cheap fiberglass reinforced plastic composites. The elaborated methodology of numerical simulation with the use of LS-DYNA software enables the essential shortening of the test period of worked out solutions.
Źródło:
Journal of KONES; 2008, 15, 4; 383-391
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Composite-polymer materials for energy-absorbing structures
Autorzy:
Barnat, W.
Niezgoda, T.
Ochelski, S.
Powiązania:
https://bibliotekanauki.pl/articles/246205.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
energy absorption structures
safety
composites
numerical simulation
energy absorption investigations
Opis:
On the basis of the results obtained from our own experimental investigations of energy- absorbing elements, the influence of the given factors on absorbed energy (WEA) was determined. The objects of the research were the samples made of epoxy composites reinforced with glass fibres formed in roving, roving stripes and glass mat as well as with carbon fibres formed in roving and carbon roving stripes. To investigate the capability of hitting energy absorption of the samples in the shape of tubes, the truncate cones and in the shape of a thin cuboid were taken under consideration. The sample in the shape of tubes, wavy coats and thin cuboids with angle 45° (on one edge), play the role of the initiator of progressive destruction process. The composites matrix was taken into account during investigations: epoxy, the vinyl-esters, polyetheretherketones, reinforced with carbon and glass fibres with different structures of the samples. The influence of the sample geometry and the orientation of the layers in carbon / epoxide and the ar amid / the epoxide composites on the WEA absorption value were presented in the papers. The comparison of the structures made f rom single elements with relevant structures of four elements shows that absorbed energy is accumulating. In this case the relative absorbed energy remains at the similar level.
Źródło:
Journal of KONES; 2009, 16, 1; 21-34
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical implementation of car impact into the modified road barrier
Autorzy:
Kiczko, A.
Niezgoda, T.
Nowak, J.
Dziewulski, P.
Powiązania:
https://bibliotekanauki.pl/articles/243992.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
road transport
car - road barrier system
crash test
numerical simulations
Opis:
In previous works the research team submitted [1-5] a series of numerical analysis of the car - road barrier dynamical system, directed to the elaboration of the numerical model methodology of an impact problem with the use of the chosen CAE programs. In this article there are presented the results of works on numerical implementation of crash tests of a car with the modified road barrier. The results are presented on the example of the Suzuki Swift car impact into the road barrier, which is equipped with the additional protective panel. The panel consists of the foamed aluminium plate whose fastening to the belt of the W-beam guardrail and a shield presented itself a thin-walled open profile made from the polyester-glass laminate. The whole construction was connected with the W-beam guardrail by riveting. The Geo Metro (Suzuki Swift) car, commonly available model from National Crash Analysis Centre (NCAC), was used for numerical analysis of the car-barrier system. Numerical analysis was carried out with the use of LS-Dyna system. The comparison of the time courses of acceleration, acting on the vehicle centre of gravity and the ways of the barrier and car deformation, achieved by the experimental and simulation ways, took place. The good qualitative and quantitative conformities in accelerations w archieved.
Źródło:
Journal of KONES; 2010, 17, 3; 189-196
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical and experimental study of armour system consisted of ceramic and ceramic- elastomer composites
Autorzy:
Chabera, P.
Boczkowska, A.
Morka, A.
Niezgoda, T.
Oziębło, A.
Witek, A.
Powiązania:
https://bibliotekanauki.pl/articles/200348.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ballistic performance
numerical simulation
ceramic
wydajność balistyczna
symulacja numeryczna
ceramiczny
Opis:
The paper presents numerical and experimental results in the study of composite armour systems for ballistic protection. The modelling of protective structures and simulation methods of experiment as well as the finite elements method were implemented in LS DYNA software. Three armour systems with different thickness of layers were analyzed. Discretization for each option was built with three dimensional elements guaranteeing satisfactory accuracy of the calculations. Two selected armour configurations have been ballistically tested using the armour piercing (AP) 7.62 mm calibre. The composite armour systems were made of Al2O3 ceramics placed on the strike face and high strength steel as a backing material. In case of one ballistic structure system an intermediate ceramic- elastomer layer was applied. Ceramic- elastomer composites were obtained from porous ceramics with porosity gradient using pressure infiltration of porous ceramics by elastomer. The urea-urethane elastomer, as a reactive liquid was introduced into pores. As a result composites, in which two phases were interconnecting three-dimensionally and topologically throughout the microstructure, were obtained. Upon ballistic impact, kinetic energy was dissipated by ceramic body The residual energy was absorbed by intermediate composite layer. Effect of the composite shell application on crack propagation of ceramic body was observed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 4; 853-859
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza MES drgań wylotu lufy podczas strzału
FE analysis of vibrations for barrels tip at shot phase
Autorzy:
Łazowski, J.
Małachowski, J.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/211133.pdf
Data publikacji:
2008
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
lufa, pocisk
modelowanie numeryczne
uzbrojenie
barrel, bullet
numerical modelling
armament
Opis:
Projektowanie uzbrojenia w dużej mierze opiera się na metodach analitycznych, które nie pozwalają na znaczną poprawę parametrów broni w zakresie odporności udarowej. Szczególnie istotna jest analiza drgań w obszarze wylotu lufy przy uwzględnieniu ruchu pocisku oraz ustalenie optymalnych parametrów procesu. Na styku wylotu lufy i pocisku zachodzi złożony proces oddziaływania obiektów, który może decydować o rozrzucie trafień w celu. Oddziaływanie to związane jest z powstawaniem składowych poprzecznych prędkości, a w konsekwencji wytrącenia pocisku z położenia równowagi. Jedyną skuteczną metodą może być w tym przypadku modelowanie numeryczne. W pracy przedstawiono propozycję metody szacowania długości lufy przy uwzględnieniu szybkozmiennych procesów, które mają miejsce w trakcie współpracy pocisku z lufą. Przedstawiono również modele numeryczne obiektów i zaprezentowano przebiegi prędkości wylotu lufy dla trzech wariantów długości: +5% i -5% w stosunku do długości bazowej (0%). Narzędziem zastosowanym do analizy był pakiet obliczeniowy LS-DYNA, umożliwiający dynamiczną analizę nieliniową z jawnym krokiem całkowania.
Currently, the design process for armament equipment mostly employs very known and traditional analytical methods. However, in many cases this kind of approach is not sufficient and effective, especially for gun parameters related with impact resistance. In the contact areas between the bullet and the barrel appear some thermo-mechanical phenomena. In such situations, the typical engineering approach in design process is unable to take into considerations all such local and very complex effects. This paper presents dynamic numerical approach of the shot phase. The models of the bullet and the barrel were developed using FE method. The main goal of the research was focused on assessment of barrel response for three different barrel's lengths: +5% and -5% according to the base barrel's lenght (0%). Thanks to such sensitive study we are able to find the optimal geometrical parameters for interacted bodies, the bullet and the barrel. Calculations were performed using the so-called direct-integration procedure, colloquially called the explicit integration implemented in LS-Dyna code.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2008, 57, 3; 235-245
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of progressive failure of composite energy absorbing structures
Autorzy:
Niezgoda, T.
Barnat, W.
Powiązania:
https://bibliotekanauki.pl/articles/243301.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport safety
road barriers
numerical analysis
energy-absorbing element
FEM
Opis:
The aim of the paper was to compare the influence of the applied fill on the energy absorbed by the energy ubsorbing structural elements made of composite, steel and from composite with fill foam. The experimental tests were carried out on an INSTRON universal testing machine at the speed rate of the machine's traverse equal 10 mm/min md the numerical analysis has been performed using MSC. Dytran software based on the Finite Element Method. The elements were subjected to axial kinematic loads. The higher specific absorbed energy occurs in the case of energy absorbing elements made of composites and from composite with fill foam. These elements can be applied in structures designed for the protection of people or limitation of the whole structure failure, e.g. in the case of a helicopter or car crash etc. The failure progressing in a relatively uniform manner results in the fact that the work md for failure of an energy absorbing element causes a substantial reduction of the impact load results. Application of energy absorbing elements may be a system dissipating the energy of a car impact into a crash barrier. The results of numerical simulation of stiffness plate hitting to the road barrier are presented. Experimental tests and numerical simulations were also presented for a composite sleeve subjected to progressive failure, which allowed carrying out simulation and analysis of a crash into a road barrier protected by a system of two such sleeves.
Źródło:
Journal of KONES; 2008, 15, 1; 169-181
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of two-component armour
Autorzy:
Kędzierski, P.
Morka, A.
Sławiński, G.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/200962.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optimization
composites
numerical simulations
ballistic protection
optymalizacja
kompozyty
symulacje numeryczne
ochrona balistyczna
Opis:
The paper presents research on optimization of two-layer armour subjected to the normal impact of the 7.62x54 B32 armour piercing (AP) projectile. There were analysed two cases in which alumina Al2O3 was supported by aluminium alloy AA2024-T3 or armour steel Armox 500T. The thicknesses of layers were determined to minimize the panel areal density whilst satisfying the constraint, which was the maximum projectile velocity after panel perforation. The problem was solved through the utilization of LS-DYNA, LS-OPT and HyperMorph engineering software. The axisymmetric model was applied to the calculation in order to provide sufficient discretization. The response of the aluminium alloy, armour steel and projectile material was described with the Johnson-Cook model, while the one of the alumina with the Johnson-Holmquist model. The study resulted in the development of a panel optimization methodology, which allows the layer thicknesses of the panel with minimum areal density to be determined. The optimization process demonstrated that the areal density of the lightest panel is 71.07 and 71.82 kg/m2 for Al2O3-Armox 500T and Al2O3-AA2024-T3, respectively. The results of optimization process were confirmed during the experimental investigation.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 1; 173--179
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary concept of numerical modelling of combustion process for gunpowder using LS-DYNA code
Wstępna koncepcja numerycznego modelowania procesu spalania ładunku miotającego w systemie LS-DYNA
Autorzy:
Łazowski, J.
Małachowski, J.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/241653.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
lufa
pocisk
modelowanie numeryczne
balistyka wewnętrzna
spalanie
barrel
bullet
numerical modelling
internal ballistic
gunpowder burning
Opis:
In this paper the preliminary concept of numerical modelling of combustion process for gunpowder is presented. Such new computational methods like finite element analysis gave us opportunity to simulate such energetic and high-frequency process like pressure wave generation caused by chemical reaction. The main product of this process is a blast wave, which interacts at the first stage with surrounding (bullet and shell) and finally impel a bullet movement. In the considered case, the detonation product from gunpowder burning couple "produced" gas in Eulerian domain with the barrel-bullet system described in Lagrangian domain. In the performed analysis, the authors noticed some unwanted effects like asymmetry, which is probably related with the finite element mesh and computational errors. In the next conducting investigations some optimisation procedures related with a bullet movement in a barrel will be employed. The successful solution of such complicated problem like a proper simulation of the internal ballistic phenomena with taking into account all dynamic effects can significantly improve the problem of shooting accuracy. The initial calculations were performed using LS-Dyna code. At this stage the presented results have a qualitative character.
W pracy omówiono koncepcję symulacji komputerowej spalania materiału wybuchowego miotającego w układzie lufa- nabój. Takie nowoczesne sposoby obliczeniowe, oparte na metodzie elementów skończonych mogą dostarczyć możliwości symulacji szybkozmiennych procesów energetycznych wynikających ze zamiany energii chemicznej prochu na ciśnienie gazów prochowych i w konsekwencji w energię kinetyczną pocisku. Okazuje się, że zamodelowanie wytwarzania produktów spalania materiału miotającego jest zadaniem trudnym. W takich ekstremalnych warunkach charakter współpracy obu ciał może być obarczony np. brakiem symetrii wynikającym między innymi z asymetrycznego rozkładu ciśnienia produktów spalania materiałów miotających. W przypadku modelu dyskretnego koncepcja ta może zostać wykorzystana do rozwiązania problemu głównego balistyki wewnętrznej i optymalizacji konstrukcji układu lufa - nabój oraz symulacji właściwości dynamicznych rozpatrywanych obiektów w różnych fazach współpracy. Poniżej przedstawiono klasyczne sformowanie modelu dla broni lufowej oparte równań matematycznych i sposób zaimplementowania w modelu dyskretnym. Rozważania zilustrowano przykładowymi wynikami. Pracę realizowano przy wykorzystaniu licencjonowanego pakietu obliczeniowego LS-Dyna. Przedstawione wstępne wyniki mają charakter jakościowy.
Źródło:
Journal of KONES; 2007, 14, 1; 255-260
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza procesu przebijania płyty przez małogabarytowy element cylindryczny
Analysis of Process of Plate Piercing by Small Dimension Cylindrical Element
Autorzy:
Panowicz, R.
Kołodziejczyk, D.
Sybilski, K.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/403921.pdf
Data publikacji:
2014
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
przebijalność
analiza numeryczna
dynamika
metoda elementów skończonych
piercing power
numerical analysis
dynamics
finite element method
Opis:
W artykule przedstawiono wstępną weryfikację oddziaływania małogabarytowego elementu cylindrycznego z przeszkodą w postaci tarczy metalowej o grubości 2,5 mm. Rozważono uderzenia z różnymi prędkościami (200, 400 i 800 m/s) oraz kątami uderzenia (30, 45, 60 i 90°), dla dwóch rodzajów materiałów: stopu aluminium PA7 oraz taśmy miedzianej. Na podstawie tych wyników określono obszar zmian, które powstały w materiale na skutek uderzenia. Trójwymiarowy model numeryczny został wykonany w systemie HyperMesh [1], a do analiz zjawisk szybkozmiennych użyto nieliniowej metody elementów skończonych zaimplementowanej w programie LS-Dyna [2]. Wykorzystanie analiz numerycznych umożliwiło śledzenie niemożliwych do zarejestrowania metodami eksperymentalnymi, rozważanych w poniższej pracy, zjawisk dynamicznych. Wykorzystując oprogramowanie LS-Dyna, można było obserwować propagację zniszczenia w kolejnych krokach czasowych, jak również rozkład naprężeń w materiale. Przeprowadzone w pracy badania pozwoliły na dokładniejsze poznanie fizyki zjawiska procesu przebijania.
The article presents an initial verification of interaction of a small dimension cylindrical element with an obstacle in the form of a 2.5 mm thick metal shield. There were considered impacts at different velocities (200 , 400 and 800 m/s) and different impact angles (30, 45, 60 and 90°) for two different types of materials: aluminium alloy PA7 and copper tape. Based on these results, there was determined the area of changes which were formed in the material as a result of the impact. A three-dimensional numerical model was developed in HyperMesh system [1] and analyses of high frequency phenomena were performed with the use of a nonlinear finite element method included in LD-Dyna software [2]. Implementation of numerical analyses would enable the investigation of the considered in the present work dynamic phenomena impossible to be recorded with experimental methods. Application of LS-Dyna enabled both the investigation of damages propagation in the subsequent time steps and stress distribution in the material. The tests carried out in the present work allowed more accurate knowledge of physics of a piercing process phenomenon.
Źródło:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa; 2014, 5, 2 (16); 77-90
2081-5891
Pojawia się w:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 20

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