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Wyświetlanie 1-12 z 12
Tytuł:
Experimental and numerical investigation of connector with elastomer joint
Autorzy:
Sławiński, G.
Malesa, P.
Niezgoda, T.
Bogusz, P.
Powiązania:
https://bibliotekanauki.pl/articles/245319.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
elastomer
connector
LS-Dyna
experimental tests
FEM analysis
Opis:
This paper presents works associated with the design, experimental tests and numerical analyses of a composite connector, which is a part responsible for increasing the safety of the soldiers. Nowadays researchers more and more often are searching for modern materials, which, as individual components or structures connected with other materials, meet the requirements of global markets. One of the most important branches of industry, which presently is growing increasingly are high technologies accompanying the safety of soldiers who are the passengers of a military vehicle. The proposed solution allows protection of the sensitive parts of body (e.g. legs), as well as the entire body of a soldier from the risks resulting from the impact of a pressure wave coming from explosion on the vehicle in which the soldier travels. A combination of classic materials, such as steel, and modern materials with hyperelastic characteristics might be an alternative to the currently used shock absorbers and dampers. Perspective can be using this assembly as a connector between a seat and the military vehicle body or special plates for protecting the crew’s feet resting on the floor of the vehicle during explosion of a mine or IED. The analysis is conducted using the LS-DYNA explicit code.
Źródło:
Journal of KONES; 2016, 23, 3; 473-480
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of true stress in engineering materials using optical deformation measurement methods
Autorzy:
Bogusz, P.
Popławski, A.
Morka, A.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/241743.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
true stress
optical deformation measurement
experimental studies
FEM
steel
Opis:
The aim of the paper is to evaluate a method of determining true stress in the steel sample subjected to static axial tensile on a universal testing machine. The tensile specimens were made of steel ST3, which was chosen because of its relatively high plastic deformations. Strain measurement was performed using traditional extensometers and additionally a non-contact optical deformation measuring system. Material properties were obtain by the extensometer measurements. The optical equipment registered the investigated sample through the optical system composed of two cameras and calculated a three-dimensional model of the material deformation in time. Displacement fields in axial and radial directions were determined with Digital Image Correlation method (DIC). Then the logarithmic axial strain map and radius shrinkage map in the area of the neck were obtained. Characteristic dimensions of the neck: curvature and width were also measured. It allowed determination of cross-section area changes in the real time, and in the result, calculation of actual true stress in the material during failure process. In this case Bridgman's and other scientists' formulas of stress distribution in the neck were applied. A numerical model, where material properties of finite elements were described by the Johnson-Cooke material model, was developed in LS-PrePost software. The FEM model was computed in LS-DYNA solver. The output tensile curve and neck curvature radius were compared with relevant data obtained from the optical measuring system.
Źródło:
Journal of KONES; 2012, 19, 4; 53-64
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Static axial crush performance of unfilled and elastomer-filled composite tubes
Autorzy:
Ochelski, S.
Bogusz, P.
Kiczko, A.
Powiązania:
https://bibliotekanauki.pl/articles/200998.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical properties
absorbed energy
polymer composites
elastomers
experimental mechanics
Opis:
The paper presents the results of the experimental static axial crush performance of unfilled and filled composite tubes. Composites are widely used as materials for energy absorbing structures because of their low density and a very high absorbed energy in relation to the mass ratio. Foamed materials are used in order to additionally increase their efficiency, because of stabilizing the progressive crush. It was proved by many authors that various foamed materials positively influence the energy absorption. In this work authors took effort to evaluate a very different material as a filler of common composite elements . elastomers. Elastomers are materials characterised by very high crush strains and viscoelastic properties. The tube shaped specimens made of epoxy composite, reinforced with carbon or glass fabrics were filled with elastomers of 40; 60; 70 and 90. ShA hardnesses. The influence of the elastomer hardness and the filling degree on the energy absorption factor (EA) was evaluated. The degree of filling the specimens with elastomers is determined by a different size of the elastomer perforation. Elastomers have a negative impact on the energy absorbed by the composite tubes.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 1; 37-43
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical investigation of connector with elastomer joint
Autorzy:
Sławiński, G.
Malesa, P.
Świerczewski, M.
Bogusz, P.
Powiązania:
https://bibliotekanauki.pl/articles/243074.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
elastomer
energy absorbing
LS-DYNA
experimental tests
FEM analysis
Opis:
This article presents works associated with the design, numerical analyses and experimental tests of an energyabsorbing mat designed for increasing the safety of the soldiers inside military vehicles, especially their legs. One of the most important branches of engineering interests is high technologies accompanying the safety of soldiers. Energy absorbing mats are one of an additional equipment of a military vehicle, which is directly targeted to increase leg safety during explosion of IED (Improvised Explosive Device) under vehicle. The presented invention allows protection legs of the crew’s feet resting on the floor of the vehicle during explosion of a mine or IED. In most solutions, crewmembers’ foot rests directly on the floor, causing serious injuries. The value of the load on the metatarsus and tibia is closely related to the overall vehicle structure, which generally has limitations in the use of available external and internal protection solutions. Energy absorbing mats are a universal solution because they are adaptable to any type of vehicle. Their role is particularly important in flat-bottomed armoured vehicles. The article will show the results of the analysis showing how the mat works. Experimental results will be compared with the results of numerical analysis. The analysis is conducted using the LS-DYNA explicit code.
Źródło:
Journal of KONES; 2017, 24, 3; 283-289
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Static axial crush performance of unfilled and foamed-filled composite tubes
Autorzy:
Ochelski, S.
Bogusz, P.
Kiczko, A.
Powiązania:
https://bibliotekanauki.pl/articles/201001.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical properties
absorbed energy
polymer composites
foamed materials
experimental mechanics
Opis:
The use and the combination of new, high efficient materials for crashworthiness is of great interest nowadays. Foamed materials are commonly used to increase efficiency of composite materials. Based on the results obtained by Brachos and Douglas, it can be concluded that the sum of the energy absorption capabilities of the foamed filling and unfilled composite tubes is smaller than the energy absorbed by the tubes filled with the same filling. The paper presents the results of the experimental investigations into the influence of filling the tubes with different materials on the impact energy absorption capability. The tube shaped specimens made of epoxy composite, reinforced with carbon or glass fabrics were filled with foamed aluminium or foamed poly(vinyl chloride). It was proved that the foamed materials increase the energy absorption and the absorbed energy of the tubes filled with foams is greater than the sum of the energy absorbed by the composite tube without filling and the foamed material itself investigated separately, when the wall thickness is more than 2 mm. The investigations of the filled tubes with the thickness of walls equal to 1 mm showed lower absorbed energy values because the crushing force had decreased during the crush. The investigations were executed to show what are the effects of filling composite energy absorbing elements in the shape of tubes with foamed materials. Additionally, influence of tube wall thickness and crush mechanism were studied.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 1; 31-35
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of hardness on mechanical properties of elastomers
Autorzy:
Ochelski, S.
Bogusz, P.
Kiczko, A.
Powiązania:
https://bibliotekanauki.pl/articles/246003.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
experimental research
elastomers
mechanical properties
relative damping coefficient
mechanical loss angle
Opis:
In this paper, elastomers with different hardness factors were examined to evaluate the influence of the hardness on their mechanical properties. The following hardness numbers, measured in Shore A hardness scale, were investigated: 40; 60; 70 and 90°. Basic mechanical tests i.e. axial tension and axial compression have been performed in order to calculate elastic properties and stress values corresponding to the fixed strains: epsilon = 0.2; 0.3 and 0.5. The sigma (epsilon) dependences from the tension and compression tests are nonlinear and have different shapes. The tension plot can be described by a convex parabola, while the compression curve can be approximated by a concave one. dynamic load tests with loading freąuencies 0.01; 0.1; 1.0 and 3,OHz were performed in order to determine the hysteresis loop and to obtain force and displacement dependences in time. From those results the following factors were calculated: relative damping coefficient and mechanical loss angle, as well as their dependence on load frequencies. The influence of hardness on both in-phase and out-of-phase components of normal modulus were investigated. The sensitivity of the examined elastomers to the loading rate was also investigated.
Źródło:
Journal of KONES; 2010, 17, 1; 317-325
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat effects measurements in process of dynamic crash of polymer composites
Autorzy:
Ochelski, S.
Bogusz, P.
Kiczko, A.
Powiązania:
https://bibliotekanauki.pl/articles/201006.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical properties
heat effect
absorbed energy
polymer composites
experimental mechanics
dynamic investigations
Opis:
In the work, the attempt to determine the influence of loading rate on temperature of the surface of the crushed composite energy absorbing elements was undertaken. The specimens made of epoxy composites reinforced with glass fabrics and carbon fabrics of the structures [(0/90)T ]n were subjected to dynamic investigations. Thermovision investigations were conducted during energy absorbing tests. A thermovision camera enables the measurement of the temperature on the whole surface of the specimen visible in the camera lens while the measurement with the use of thermocouple is only local and has great heat inertia. During the investigations, the increase of specimen temperature related to impact velocity occurs. The temperature increase is caused by friction between the particles of the crushed specimen and by friction between the specimen and the support of the strength machine. At high loading rates, the increase of temperature on the surface of the specimens was significantly greater than the softening temperature of the epoxy resin E-53.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 1; 25-30
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
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 investigations of double multi - leaf spring subjected to impact load
Autorzy:
Bogusz, P.
Krasoń, W.
Wysocki, J.
Powiązania:
https://bibliotekanauki.pl/articles/247312.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
double multi-leaf spring
suspension of a motor truck
impact load
experimental investigations
Opis:
The article deals with experimental investigations of a prototype double multi-leaf spring, compound of a fourleaf main spring and a double-leaf supporting spring subjected to an impact test. In real conditions of car movement (e.g. curb, bump), dynamic oscillating loads, which generate dynamic stress in a car suspension affecting other elements of the car, occur. Consequently, effects of coupled oscillations having a great impact on comfort of a driver and passengers can be observed. The research was conducted in the Laboratory of Material and Construction Strength Department of Mechanics and Applied Computer Science (DMACS) in the Faculty of Mechanical Engineering of Military University of Technology. The experiment was carried out on an original construction of a spring impact hammer developed in DMACS. Energy of the impact was set up by changing mass of a beam with beater and beam dropping height. The results were presented in the form of table summaries, time-dependent load and displacement graphs. The methodology of the research presented in the paper and a set of measuring equipment can be utilized to evaluate load and vibrations of any multi-leaf spring under impact load with given energy. The experimental results obtained from the test are supposed to be used to verify and develop FEM model describing a spring under impact load and oscillations.
Źródło:
Journal of KONES; 2012, 19, 2; 45-51
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crushing behaviour of the PVC foam loaded with beaters of various shapes
Autorzy:
Bogusz, P.
Gieleta, R.
Stankiewicz, M.
Konarzewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/387664.pdf
Data publikacji:
2018
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
polymer foam
polyvinyl chloride foam
hitting with a blunt object
energy absorption
impact tests
experimental mechanics
Opis:
Statistically, at least 50% of all injuries experienced by police officers in the line of duty are due to assaults with blunt objects. Therefore, vests used by the police should provide not only good ballistic resistance, but also good protection against such threats. Foamed materials are possible to be used for body protectors or inserts of protective clothes. The effects of dynamic impact with beaters of different shapes onto behaviour of polymeric foamed material were determined. There were used four types of beaters: flat, cylindrical, edgy and cornered. Strikes with blunt objects such as a flat board, baseball bat, edgy brick, pavement brick or a sharp stone, to which a protective ware can be subjected, were simulated. The impact load was applied to the rectangular specimens, made of polyvinyl chloride foam, with a usage of a drop hammer. Plots of force versus compression for all the tested samples were obtained and analysed. The effects of impacts with beaters of different shapes onto foamed material samples were presented. A shape of the blunt object significantly influences crushing behaviour of the foamed material. The impact energy of a flat beater is absorbed effectively on a short distance, since it is spread on a relatively large surface. The cylindrical and edgy beaters did not cause fragmentation of the samples, however, on the upper surfaces of the samples, permanent deformations mapping the beaters shapes as well as some cracks occurred. An impact with a sharp object, for example, a cornered beater is very difficult to be neutralized by the foam material, because it is cumulated on a small area.
Źródło:
Acta Mechanica et Automatica; 2018, 12, 1; 23-30
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wypełnienia rurek na zdolność pochłaniania energii uderzenia
Influence of tubes filling on capability of impact energy absorption
Autorzy:
Barnat, W.
Bogusz, P.
Ochelski, S.
Powiązania:
https://bibliotekanauki.pl/articles/209439.pdf
Data publikacji:
2009
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
właściwości mechaniczne
energia absorbowana
kompozyty polimerowe
mechanika doświadczalna
mechanical properties
absorbed energy
polymer composites
experimental mechanics
Opis:
W artykule przedstawiono wyniki doświadczalnych badań wpływu wypełnienia próbek spienionymi tworzywami na zdolność pochłaniania energii uderzenia. Próbki w kształcie rurek wykonanych z kompozytu epoksydowego wzmocnionego tkaninami węglowymi i szklanymi, wypełniano spienionym aluminium i spienionym poli(chlorkiem winylu). Wykazano, że wypełnienie rurek zwiększa pochłanianie energii, gdy grubość ścianki rurki jest większa od 2 mm oraz energia pochłaniana rurki wypełnionej jest większa od sumy energii rurki bez wypełnienia i tworzywa spienionego. Badania wypełnionych rurek o grubości ścianek 1 mm wykazały mniejszą energię absorbowaną, ponieważ niszczyły się przy mniejszej sile aniżeli rurki bez wypełnienia.
This paper presents the experimental investigations of the impact energy absorption capability of the composite tubes filled with different foamed materials. Inside the tube specimens made of epoxy resin reinforced with carbon and glass fabric, aluminum foam or PVC foam cylinders were glued. It was proved that the foamed material filling increases the impact energy absorption for composite specimens with wall thickness greater than 2 mm. The value of the absorbed energy is greater than the algebraic sum of the energy absorbed by the same specimen without filling and the energy absorbed by the foamed material cylinder. It was shown that the filled specimens with a thickness of 1 mm absorbed less impact energy than the specimens without filling, because the mean crush load was clearly lower.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2009, 58, 3; 87-101
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efekty cieplne w procesie dynamicznego niszczenia kompozytów polimerowych
Heat effects in dynamic crush of polymer composites
Autorzy:
Ochelski, S.
Bogusz, P.
Powiązania:
https://bibliotekanauki.pl/articles/210658.pdf
Data publikacji:
2011
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
właściwości mechaniczne
efekt cieplny
energia absorbowana
kompozyty polimerowe
mechanika doświadczalna
badania dynamiczne
mechanical properties
heat effects
absorbed energy
polymer composites
experimental mechanics
dynamic investigations
Opis:
Przedstawiono wyniki doświadczalnych badań wpływu prędkości uderzenia na przyrost temperatury na powierzchni próbki. Podczas badań energochłonnych elementów kompozytowych następuje wzrost temperatury próbki, który jest zależny od prędkości uderzenia. Wzrost temperatury jest spowodowany tarciem cząsteczek niszczonej próbki i tarciem próbki o podporę maszyny wytrzymałościowej. W pracy [1] przeprowadzono badania dotyczące rozpraszania energii poprzez tarcie, podczas progresywnego niszczenia kompozytowych rurek, pomiędzy płytami o różnej chropowatości, natomiast nie dokonywano pomiaru temperatury próbek. W pracy podjęto próbę określenia wpływu prędkości obciążenia na temperaturę powierzchni niszczonej próbki. Przeprowadzono badania termowizyjne elementów energochłonnych, które wykonano z kompozytów polimerowych o różnym rodzaju wzmocnienia i o różnej strukturze. Badaniom dynamicznym z pomiarem temperatury poddano próbki wykonane z kompozytów epoksydowych wzmocnionych matą szklaną, które mają wysokie właściwości lepkosprężyste, a także kompozyty wzmocnione włóknami szklanymi i węglowymi o strukturze [(0/90)T]n, w których dominują właściwości sprężyste. Przy dużych prędkościach obciążenia, wzrost temperatury na powierzchni próbek był znacznie większy od temperatury mięknięcia żywicy epoksydowej.
The paper presents the experimental results of loading rate influence on the temperature rise on the surface of polymer composites. The investigations showed that during the progressive crush of composite elements, the temperature of the specimen rises significantly, dependently on the loading rate. This effect is mainly caused by friction of composite molecules and friction between bended composite layers and the strength machine. In work [1], the investigations concerned the energy dissipation in progressive crush of composite tubes by a friction effect between composite material and steel plates with different surface roughness. In this case, the temperature was not measured. This work deals with the investigation of temperature growth on the surface of the composite energy absorbing elements in the shape of a tube. The dynamic tests were performed on polymer composites with different reinforcement orientation (different viscoelastic properties). Specimens made of epoxy resin reinforced with glass mat are characterized by strong viscoelastic properties. Composites reinforced with glass and carbon fabrics [(0/90)T]n have mainly elastic properties. The temperature field was measured by the infrared high speed camera. In high speed impact tests, the temperature was significantly higher than the melting temperature of the epoxy resin.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2011, 60, 4; 79-90
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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