Wyniki wyszukiwania - Biblioteka Nauki

1

Modelling and numerical simulations of a TB51 road crash test using a simplified coach model

100%

Dziewulski P.

Archiwum Motoryzacji

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2016

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tom Vol. 72, nr 2

29--42

EN

The paper proposes a methodology of a TB51 virtual crash test on the example of the selected bridge protective barrier, using a simplified coach model. In simulations of crash tests, the nonlinear, explicit finite element code LS-Dyna v971 was used. The simulation results corresponding to the simplified model were compared with the simulation results for a quasi-accurate model and the experimental crash test results. It was shown that the simplified vehicle model can be used in tests certifying a barrier modified in relation to the certified reference barrier.

PL

W pracy zaproponowano metodologię wirtualnego badania zderzeniowego TB51 wg normy PN-EN 1317 na przykładzie wybranej mostowej bariery ochronnej, z zastosowaniem uproszczonego modelu autobusu. Celowo zrezygnowano z wpływu zawieszenia, tarcia kół o nawierzchnię, obrotu wokół poziomych osi centralnych pojazdu oraz maksymalnie uproszczono strefy zgniotu. Celem jest skrócenie symulacji i umożliwienie szybkiej kalibracji modelu pojazdu. Takie podejście pomoże również jednostkom certyfikującym w ocenie wyników ze względu na uproszczenie i ujednolicenie pojazdów używanych w symulacjach uderzenia w barierę. Wyniki symulacji odpowiadające modelowi uproszczonemu porównano z wynikami symulacji dla modelu quasi-dokładnego oraz z wynikami eksperymentalnego testu zderzeniowego. Wykazano, że uproszczony model pojazdu może być zastosowany do badań certyfikujących bariery zmodyfikowanej w stosunku do bariery referencyjnej mającej certyfikat. Do symulacji testów zderzeniowych zastosowano nieliniowy jawny kod Metody Elementów Skończonych LS-Dyna v971.

2

Development of finite element model of shunting locomotive applicable for dynamic analyses

63%

Dziewulski P. , Szurgott P.

Journal of KONES

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2014

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tom Vol. 21, No. 4

95--102

EN

The main aim of this study is to develop a finite element model of the hybrid-shunting locomotive. Considered locomotive is based on a popular shunting locomotive in Poland – SM42. All components above the locomotive frame could be modified in comparison to the original object, whereas a chassis was essentially unchanged. Such solution allows the operators freely configure components e.g. diesel engine, generator, cooling module, cab etc., according to their own requirements. Works on the FE model were focused on very accurate reflection of the locomotive frame since the planned dynamic analyses include crash tests. FE model of the frame has a fine mesh and it is considered as a deformable component. Other segments of the vehicle are simplified and treated as rigid bodies mostly. FE model was developed on the basis of the locomotive CAD model. It was decided to transform the CAD model of the frame into the FE one applying the midsurface procedure. Such approach is correct since the locomotive frame is made of a large number of steel elements in the form of sheet metal plates and sections welded together. Altair Hyper Mesh software was used in the FE model developing process. Appropriate connections between respective components of the model e.g. wheelset – bogie, bogie – locomotive frame, were applied. Finally, the locomotive FE model consists of about 116 thousands of finite shell and solid elements and about 125 thousands of nodes. Dynamic analyses of the locomotive FE model will be carried out using LS-DYNA computer code.

3

Numerical analysis of collision between locomotive and passenger car located on level crossing

63%

Szurgott P. , Dziewulski P.

Journal of KONES

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2014

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tom Vol. 21, No. 4

489--496

EN

The main aim of this study is to carry out dynamic finite element analysis of a collision between shunting locomotive and a passenger car. Numerical simulations include side impact of the running locomotive in the vehicle situated across the track on a level crossing. A considered locomotive based on a popular diesel-electric shunting locomotive SM42 but it was slightly modernized in comparison with the original. Finite element model of the locomotive was developed by the authors whereas the vehicle FE model was download from the National Crashworthiness Analysis Center database and it was dedicated to the crash/impact analyses. FE analysis was carried out according to the PN-EN 15227 standard which provides crashworthiness requirements for railway vehicle bodies. However, additional objective of the analysis was to evaluate the behaviour of a small passenger car during the side impact with about 70-ton locomotive. A subcompact passenger car – Geo Metro – was selected as a representative for the study. One of the design collision scenario impact into low obstacle for railway vehicles operated on national and regional networks. LS-DYNA computer code was used for the simulations. The paper presents selected results of analysis generally focused on the locomotive frame behaviour. Contour of stress for the moment of time is presented. Moreover, time histories of selected parameters are depicted. The energy balance was also checked in order to confirm the accuracy of analysis.

4

Investigation of road barriers on their abilities to absorb energy of hitting

51%

Niezgoda T. , Kiczko A. , Barnat W. , Dziewulski P.

Journal of KONES

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2008

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tom Vol. 15, No. 4

383-391

EN

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.

5

Numerical Modelling, Simulation and Validation of the SPS and PS Systems under 6 kg TNT Blast Shock Wave

51%

Świerczewski M. , Klasztorny M. , Dziewulski P. , Gotowicki P.

Acta Mechanica et Automatica

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2012

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tom Vol. 6, no. 3

77-87

EN

The paper develops a new methodology of FE modelling and simulation of the SPS and SP systems under 6 kg TNT blast shock wave. SPS code refers to the range stand – protected plate – protective shield ALF system, while PS code refers to the range stand – protected plate system. The multiple – use portable range stand for testing protective shields against blast loadings was developed under Research and Development Project No. O 0062 R00 06. System SPS uses high strength M20 erection bolts to connect the protective shield to the protected plate. In reference to the SPS system, validation explosion test was performed. It has pointed out that the developed methodology of numerical modelling and simulation of SPS and PS systems, using CATIA , HyperMesh, LS-Dyna, and LS-PrePost software, is correct and the ALF protective shield panels have increased blast resistance and high energy – absorption capability

6

Modelowanie i symulacja numeryczna wężykowania szybkobieżnego pojazdu szynowego Shinkansen na torze prostoliniowym

51%

Klasztorny M. , Niezgoda T. , Dziewulski P.

Biuletyn Wojskowej Akademii Technicznej

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2011

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tom Vol. 60, nr 1

309-324

PL

W pracy opracowano model dynamiczny 3D (fizyczny, geometryczny i numeryczny) japońskiego szybkobieżnego pojazdu szynowego SHINKANSEN poruszającego się po torze prostoliniowym niepodatnym, o stożkowatości szyn 1:20. Opracowano metodykę modelowania układu pojazd ruchomy-szyny (MV-R) oraz modelowania wężykowania z możliwością uderzeń bocznych obrzeży kół o główki szyn. Zastosowano licencjonowane oprogramowanie CATIA V5R15, HYPERMESH v10, LS-DYNA v971. Przeprowadzono badania symulacyjne wężykowania pojazdu SHINKANSEN w zakresie prędkości 100-300 km/h. Większość podukładów układu pojazd ruchomy-szyny (MV-R) zamodelowano jako bryły idealnie sztywne. Stalowe obręcze kół pojazdu oraz górne części stalowych główek szyn zamodelowano jako odkształcalne i wykonane z materiału izotropowego liniowo-sprężystego. Łożyska osi zestawów kołowych pojazdu SHINKANSEN zamodelowano za pomocą więzów CONSTRAINED_JOINT_REVOLUTE. Uwzględniono kontakt pomiędzy obręczami kół i główkami szyn typu AUTOMATIC_SINGLE_SURFACE, z zastosowaniem funkcji kary. Uwzględniono tarcie kinetyczne Coulomba na styku powierzchni tocznych i obrzeży obręczy kół i główek szyn. Analizowano przyspieszenia poziome poprzeczne reprezentatywnych punktów nadwozia oraz przemieszczenia poziome poprzeczne środków ciężkości zestawów kołowych.

EN

The study develops the 3D dynamic model (physical, geometrical, and numerical) of a high-speed Shinkansen rail-vehicle moving on a rectilinear track of 1:20 rail-head conicity. A new methodology has been developed for modelling the moving vehicle-rails system (MV-R) as well as for modelling lateral vibrations of the vehicle, induced by snaking and possible impacts of wheel flanges onto rail heads. Advanced licensed CAE software has been applied, i.e., CATIA V5R15, HYPERMESH v10, and LS-DYNA v971. Numerical simulations have been performed for service velocities of a Shinkansen rail-vehicle ranged from 150 to 300 km/h. The partial geometric model of the MV-R system has been created with CATIA V5R15 software, using the Assembly Design, Part Design, Generative Shape Design modules. The geometric model in the universal form (the STEP file) has been carried into HYPERMESH v10 system in order to build the complete equivalent geometric model, to make FEM meshing, and to declare the initial and boundary conditions. Most subsystems have been modelled in LS-DYNA v971 as rigid bodies (MAT_020). Tyres and the rail heads are deformable and made of linear-elastic isotropic steel (MAT_001). Radial bearings of wheel-set axles have been modelled with CONSTRAINED_JOINT_REVOLUTE, as shown in Figure 1. The 1st and 2nd stage 3D linearly-viscoelastic suspensions (MAT_066) have been reflected with the zero-length elements of properties SECTION_BEAM, in Discrete Beam formulation. In order to activate gravity forces, the FE locations have been removed to the predicted final static state, and then the gravity forces reflecting the total weight of the vehicle have been put onto the wheel-set axle-bearing cases. After the dynamic relaxation process, all elements of the body and bogie frames had got the initial velocity in the longitudinal direction (coinciding the track axis), whereas the rotating parts (wheels and axles) had got the angular velocity about respective axle axes. In order to keep the constant service velocity, all wheel sets had got a constant angular velocity. In order to unbalance the rail-vehicle, the body has been loaded by lateral moment impact of rectangular shape and of 22 kNms value. The tyre-rail head contact of AUTOMATIC_SINGLE_SURFACE type has been used taking into account the penalty function. The kinetic dry friction coefficient is equal to 0.10. The average time step was equal to dt = 1.23 μs. The calculations in the LS-DYNA system have been performed using double precision. The real process lasting 7.2 seconds was simulated numerically for 104 hours, using 8 processors of the cluster. The final results constitute: lateral displacements and accelerations of the representative points of the body and the lateral displacements of the gravity centres of the wheel sets. Exemplary time histories are presented in the study. The main conclusions resulting from numerical simulations are as follows. The CAE software used in the study is a very effective tool for 3D numerical simulations of the MV-R system taking into consideration a curvilinear cross-section of the rail heads, the one-side contact of wheels and rails and the Coulomb friction. The simulations show that anti-symmetric unbalance rapidly tends to stable symmetric lateral vibrations of the bogies of frequency depended on the service velocity. The lateral vibration frequencies belong to the interval 1.7-4.2 Hz.

7

Analiza wpływu prędkości na poziom powstrzymywania drogowych barier ochronnych

51%

Małek E. , Dziewulski P. , Niezgoda T. , Szymczyk W.

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2016

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tom Nr 5

46--48

PL

W pracy podjęto próbę rozwiązania problemu związanego z wpływem prędkości na stopień powstrzymywania drogowych barier ochronnych dla tych prędkości, które nie zostały uwzględnione w kryteriach badań zderzeniowych dotyczących pojazdu według normy PN-EN 1317. Ze względu na ograniczony zakres zmiennych (prędkość, kąt uderzenia i rodzaj pojazdu), przy których bada się bariery, nasuwa się pytanie, jak zmienią się podstawowe parametry funkcjonalne systemów dla innych prędkości, kątów uderzenia czy mas pojazdów.

EN

The purpose of the paper is to present an attempt to solve the problem of the impact of velocity on the containment level of road traffic barriers for those velocities which were not included in the criteria of crash tests according to PN-EN 1317 standard. Due to a limited range of variables (velocity, angle of impact and the type of vehicle) for which traffic barriers are tested, the question arises: how the basic functional parameters of systems will change for other velocities, angles of impact and masses of vehicles. The conducted analysis shows that the number of levels of containment has been significantly reduced, because at velocities lower than those included in the standard there is no need to use such high levels of containment.

8

Numeryczna analiza uderzenia motocyklisty w drogową barierę ochronną z dodatkowymi elementami energochłonnymi poprawiającymi bezpieczeństwo bierne

51%

Dziewulski P. , Niezgoda T. , Barnat W.

|

2010

|

tom R. 51, nr 4

293-296

PL

W pracy rozważono problem związany z symulacją numeryczną zderzenia manekina HYBRID III z drogową barierą ochronną. Poszczególne przypadki były analizowane numerycznie dla modelu rzeczywistej bariery SP-05 z dodatkowymi mianami konstrukcyjnymi poprawiającymi bezpieczeństwo bierne użytkowników dróg. Dodatkowo sprawdzono wpływ modyfikacji barier na zachowanie się pojazdów samochodowych w czasie uderzenia. Do analiz numerycznych układu samochód - bariera wykorzystano ogólnie dostępny model numeryczny samochodu Geo Metro, zmodyfikowany i walidowany eksperymentalnie.

EN

The problem in work was considered numerical simulation the crash of dummy HYBRID III from road protective barrier. The individual cases be analyzed for model of real barrier SP-05 with absorption hit energy elements. The modification of barriers was checked on behavior the car vehicles in time of hitting additionally.

9

Numerical study on the modification effect of the seat load acting on a soldier during the blast wave derived from IED explosion

51%

Sławiński G. , Dziewulski P. , Niezgoda T. , Malesa P.

Journal of KONES

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2016

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tom Vol. 23, No. 3

465--472

EN

The structure of a vehicle located in the explosion area of an anti-vehicle mine or an IED is subject to a strong impact of a blast wave. The explosion of a mine produces a blast wave that travels in all directions at a speed greater than the speed of sound. The level of risk to the crew of a military vehicle depends on their distance from the place of detonation, on the vehicle’s design and in particular on the design of the bottom of the hull and on the assembly and type of seats. The article provides the analysis of the impact of a side explosion on the crew of an armoured vehicle. Since the new classified version of the AEP-55 document, which defines the conditions for testing the resistance of military vehicles to explosions affecting their side, is not available, it was assumed in the numerical analysis that the charge weight of the explosive device is 100 kg TNT, placed between the central vehicle axles at the distance of 400 mm from the bottom and 1,000 mm from the lower board. Two cases were analysed: one where the Hybrid III dummy was placed on the reference seat and the other where it was placed on a modified seat. The analysis is conducted using the LS-DYNA explicit code. Only the vehicle’s hull is considered with suspension and the turret is modelled with mass.

10

Investigation of human body exposed to blast wave derived from improvised explosive devices

51%

Sławiński G. , Dziewulski P. , Niezgoda T.

Journal of KONES

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2015

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tom Vol. 22, No. 4

287--294

EN

The analysis of contemporary military conflicts shows, that the most dangerous threat for soldiers are Improvised Explosive Devices (IEDs). Blast resistance of military vehicles and structures is broadly discussed in many articles. However, information about human body response to impact loading is hard to find and very general. Both experi-mental trials with dummies and numerical analyses are needed. To design and develop better protection system it is necessary to identify and measure the effects of blast wave impact on crew of military vehicle. This paper presents numerical simulation results of special armoured vehicle subjected to mine threat of 8 and 10 kg of TNT. Possible effects of mine explosion on human body are described. Review of modern-mine and IED countermeasure solutions is presented. The analysis is conducted using LS-DYNA explicit code. Only vehicle’s hull is considered with suspension and turret is modelled using mass. Gravity is taken into account. Numerical model of Hybrid-III dummy is used. Accelerations and forces in tibia, neck and spine were calculated. HIC-36 criterion was also evaluated Different types of possible seat configuration are examined. Results show convergence between explosive size and injury risk.

11

Stateczność cienkościennych powłok cylindrycznych poddanych uderzeniu płytą sztywną

51%

Miedzińska D. , Jachimowicz J. , Dziewulski P.

Biuletyn Wojskowej Akademii Technicznej

|

2010

|

tom Vol. 59, nr 1

131-141

PL

W artykule przedstawiono wyniki dynamicznych analiz numerycznych procesu wyboczenia cienkościennej powłoki cylindrycznej poddanej obciążeniom uderzenia nieskończenie sztywną płytą, której nadano różne wartości energii kinetycznej. Pokazano wpływ tej energii na proces deformacji powłoki oraz na wartości sił krytycznych, przy których konstrukcja traci stateczność. Przedstawiono ogólne równania metody elementów skończonych używanych do obliczeń procesów dynamicznych.

EN

The results of dynamic numerical analyses of stability of thin-walled steel cylinders exposed to an impact load from an infinitely rigid plate with variable kinetic energy were presented. The influence of this energy and velocities on the deformation process and critical force values (forces causing the instability) was shown. Also the theoretical bases of the instability phenomenon were presented as well as the FEM formulas for dynamic processes.

12

Walidacja pian niemetalicznych w złożonym stanie odkształcenia

51%

Barnat W. , Dziewulski P. , Niezgoda T.

Acta Mechanica et Automatica

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2009

|

tom Vol. 3, no. 3

5-8

PL

W niniejszym artykule przedstawiono wyniki badań energochłonności piany niemetalicznej obciążonej przemieszczeniem. Głównym celem pracy była walidacja modelu numerycznego spienionego polichlorku winylu wraz z oceną zdolności pochłaniania energii przez podstawowy element konstrukcji energochłonnej obciążonej dynamicznie. Elementy energochłonne przebadano w KMiIS. Badania przeprowadzono na maszynie wytrzymałościowej Instron. Obciążenie realizowano przez wymuszenie kinematyczne.

EN

In the present article, the results of investigations of energy absorption foam structures weighted down were presented. The main objective of this study was the validations of constitutive models for non metallic foam. Investigations were conducted on Dynamic Testing System INSTRON in KMiIS. The load was applied by input function kinematic.

13

Modelling and numerical simulation of the protectiye shield - protected plate - test stand system under blast shock wave

51%

Klasztorny M. , Dziewulski P. , Niezgoda T. , Morka A.

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tom Vol. 17, No. 3

197-204

EN

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.

14

Numerical implementation of car impact into the modified road barrier

51%

Kiczko A. , Niezgoda T. , Nowak J. , Dziewulski P.

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tom Vol. 17, No. 3

189-196

EN

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.

15

Validation of numerical models of metallic foams from the aspect of energy absorption

51%

Włodarczyk J. , Niezgoda T. , Barnat W. , Dziewulski P.

Journal of KONES

|

2007

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tom Vol. 14, No. 2

561-569

EN

The main objective of the paper is to assess the energy absorbing capabilities of metallic foams. The results of experimental investigation of energy absorbing capabilities for three metallic foams under kinematic loading are presented. The tests were conducted on the INSTRON Dynamic Testing System. The numerical computations were carried out using the LS DYNA code. For metallic foam modelling, MAT_26 (MAT_HONEYCOMB) was used; it is normally used for "honeycombs" and anisotropic foams modelling. For numerical calculations, two types of numeric elements were used: SOLIDE and Plate types. SOLID type elements were used for foam modelling, and Schell types -for charge definition. A numeric diagram is presented on drawing 10. As in the case of real tested elements, the foam element was charged by a plate of velocity of 5 m/s. The metallic foam was checked in Mechanics and Applied Informatics Faculty of Military University of Technology. Tests were made on INSTRON resistance machine. The charge was made using cinematic input function. Presented results are preliminary one, the experiment was made in order to choose a foam material having the best energy absorption characteristics. The conclusion of preliminary estimation of obtained results is that the samples with the smallest pores have the most important energy absorption level. Nevertheless, the following stage of the works should be impact resistance tests: deceleration test in the aspect of security improvement.

PL

Głównym celem pracy była ocena zdolności pochłaniania energii przez piany metaliczne. W niniejszym artykule przedstawiono wyniki eksperymentalnych badań energochłonności trzech pian metalicznych obciążonych przemieszczeniem. Analizę numeryczna pianki metalicznej przeprowadzono w oprogramowaniu LS DYNA. Do modelowania piany metalicznej zastosowano MAT_26 (MAT_ HONEYCOMB) który jest używany głównie do modelowania "plastrów miodu" i pianek z właściwościami anizotropowymi. Do obliczeń numerycznych wykorzystano dwa rodzaje elementów numerycznych: typu SOLID i Plate. Elementy typu SOLID były wykorzystywane do modelowania pianki a typu Schell wykorzystywano do zdefiniowania obciążenia. Model numeryczny przedstawiono na rys. 10. Element piankowy został podobnie jak w przypadku badanych obiektów rzeczywistych obciążony płytą poruszającą się z prędkością 5 m/s. Pianę metaliczną przebadano w Katedrze Mechaniki i Informatyki Stosowanej WAT. Badania przeprowadzono na maszynie wytrzymałościowej INSTRON. Obciążenie realizowano przez wymuszenie kinematyczne. Przedstawione wyniki są wstępnymi, eksperyment został przeprowadzony w celu wybrania materiału piankowego o największej energochłonności. Na podstawie wstępnej oceny uzyskanych wyników można powiedzieć, że próbki z najmniejszymi porami posiadają największą energochłonność. Jednakże kolejnym etapem prac powinny być badania udarnościowe pomiaru opóźnień w aspekcie zwiększenia bezpieczeństwa.

16

Funkcjonowanie Zrzeszenia Przedsiębiorstw Przemysłu Mięsnego. Propozycje zmian struktur organizacyjnych w kluczowym przemyśle mięsnym. Część VI

51%

Mizielinska W. , Dziewulski P. , Smuga T. , Sobota J.

Gospodarka Mięsna

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1985

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tom 37

|

nr 06

17

Numerical modelling and design of ALFC shield loaded by 20 MM FSP fragment

51%

Klasztorny M. , Świerczewski M. , Dziewulski P. , Morka A.

Journal of KONES

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2012

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tom Vol. 19, No. 4

301-313

EN

The study develops numerical modelling and design of the ALFC shield loaded by the 20 mm 54 g FSP fragment moving at impact velocity of 1800 m/s (fragmentation simulation of IED devices), used to protect 5 mm-thick Armox 500T steel plate. The ALFC shield is composed of the ALF energy-absorbing subsystem and a 99.7% Al2O3 alumina ceramic layer. The ALF subsystem is designed to absorb blast wave impact energy induced by explosive materials up to 10 kg TNT. The ceramic layer is aimed at stopping FSP fragments. The 5 mm-thick Armox 500T steel plate reflects the body bottom segment of a light armoured vehicle. The main purpose of the study is to determine the minimum thickness of the ceramic layer at which the 5 mm-thick Armox 500T steel plate is fully protected from perforation. The ALF subsystem has the following layered structure: Al2024 aluminium alloy plate, SCACS hybrid laminate plate, ALPORAS aluminium foam, SCACS hybrid laminate plate. The layers are joined with Soudaseal 2K chemoset glue. SCACS hybrid laminate contains the following components: VE 11-M modified vinylester resin (matrix), SWR800 glass S plain weave fabric, Tenax HTA40 6K carbon plain weave fabric, Kevlar 49 T 968 aramid plain weave fabric. The total thickness of the ALF shield amounts to 76 mm. In the numerical modelling, the aluminium alloy plate and Armox 500T steel plate are working in the elasto-plastic range according to Johnson–Cook model. The 99.7% Al2O3 alumina ceramic is working in elasto--hort range according to JH-2 Johnson-Holmquist model. The simulations correspond to large displacements, large deformations and contact among all the components of the system. In FE mesh, the 8-node 24 DOF hexahedral finite elements with single integration point have been used. Additional failure criteria governing ad-hoc erosion of finite elements have been applied. The FEM modelling, simulation and postprocessing have been carried out using Catia, HyperMesh, LS-DYNA and LS-PrePost systems. The simulation results are presented in the form of displacement - perforation contours and the FSP final deformation for both the FSP–shield-plate and the FSP-plate systems. It has been pointed out that 18 mm-thick ceramic layer protects the LAV body bottom plate from perforation.

18

Wykorzystanie symulacji zderzeń pojazdu z barierą ochronną dla celów poprawy BRD

51%

Dziewulski P. , Niezgoda T. , Barnat W. , Sławiński G.

Drogi : budownictwo infrastrukturalne

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2013

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tom Nr 4 (16)

24-34

PL

W artykule przedstawiono metodykę numerycznego modelowania crash-testów drogowych na przykładzie wybranego układu pojazd-drogowa bariera ochronna oraz możliwości nowoczesnych systemów obliczeniowych do numerycznej symulacji przebiegu zderzeń. Dzięki wykorzystaniu nowoczesnych systemów CAD/CAE możliwa jest dogłębna analiza problemu, w tym analiza pól naprężeń, odkształceń oraz energochłonności badanych układów.

EN

The paper presents the methodology of numerical modelling of road crash tests based on the selected vehicle-road barrier system using the possibilities of modern CAD/CAE computing systems for a numerical simulation process of the collision. Owing to these systems, thorough analysis of the process of collision, including the analysis of the stress and strain fields and energy consumption in the tested systems, is possible. It is possible to design and redesign virtually the barriers' at a relatively low cost. Taking into consideration an experimental approach, it is impossible to achieve such results, and such an advanced design. The authors also pointed out the issue of reliability of the results obtained by simulation. Determination of accuracy of numerical models should always be preceded by identity material research oriented to determine the constants for material models. Experimental validation of the numerical results is also required. Some results of experimental validation of numerical modelling based on bending of B-type guide of a road barrier at an angle of 20°and collision of Suzuki Swift vehicle with a fragment of a road barrier in varies configurations are presented. The graphs of forces in a function of displacements and accelerations of the vehicle at the selected points were compared. The division into finite elements and preparation of a numerical model were performed in HYPERMESH system and dynamic calculations in LS-DYNA system, which is advanced implementation of the finite element method to the fast-changing phenomena. The analysis took into account the gravitational interaction and contact with friction.

19

Numerical analysis of impact between shunting locomotive and selected road vehicle

51%

Dziewulski P. , Stankiewicz M. , Szurgott P.

Journal of KONES

|

2014

|

tom Vol. 21, No. 4

87--94

EN

The main aim of this study is to carry out dynamic finite element analysis of a crash between shunting locomotive and selected road vehicle. Numerical simulations include side impact of the running locomotive in the vehicle situated across the track. A considered locomotive based on a popular Polish shunting locomotive – SM42. However, the tested locomotive was slightly modernized in comparison with the original one. Finite element model of the locomotive was developed by the authors whereas the vehicle FE model was download from the free database of such models. FE analysis was carried out according to the PN-EN 15227 standard which provides crashworthiness requirements for railway vehicle bodies. 15 tons large truck was selected as a representative for the study. One of the design collision scenario includes such deformable obstacle for railway vehicles operated on national and regional networks. LS-DYNA computer code was used for the simulations. The paper presents selected results of analysis generally focused on the locomotive frame behaviour. Contours of stress for selected moments of time are presented. Moreover, time histories of selected parameters are depicted. The energy balance was also checked in order to confirm the accuracy of analysis. The current study is a part of the project focused on modernization of the SM42 locomotive. Therefore, it is required to evaluate the locomotive behaviour during the impact test. Dynamic numerical simulation are acceptable since the experimental tests on the complete objects under consideration are impractical and impossible at the moment.

20

Numerical analysis of road infrastructure components on an example of SP -01, SP -04 and SP -09 barriers

51%

Niezgoda T. , Barnat W. , Dziewulski P.

Journal of KONES

|

2007

|

tom Vol. 14, No. 3

451-458

EN

The paper presents results of numerical investigations on elements of road infrastructure, such as the protective barriers. Three selected structural elements of road barriers: SP-01, SP-04 and SP-09 have been analyzed. For stakes, separators and guides modelling, shell type elements were applied. Specialised finite elements method software - MSC Dytran, permitting to quickly variable processes simulating -was used for analyse. Numeric simulations of crash process were done, for different configurations of structure solutions, and this permit to deeply analyze the road barriers deformation character. The chosen cases of numeric models were verified in empirical mode and this permit do make a total resistance analyze of all energy absorbing structure during crash. The SP-01 barrier has the littlest value of retardation impulse, which is the result of complicated method of structure deformation resulting from bending and torsion of the stake (using an extension arm). Such important energy absorption is due to system eccentricity, resulting from eccentricity due to a long connector. Obtained results will be used as guidelines to elaborate a method for such structures examination, and it will be possible to use them in the future research jobs in the frame of security augmentation in the road transport.

PL

W artykule przedstawiono wyniki numerycznych prac badawczych nad elementami infrastruktury drogowej w postaci barier ochronnych. Analizie poddano trzy wybrane elementy konstrukcyjne barier drogowych SP-01, spP-04 i SP-09. Do zamodelowania słupków, przekładek, prowadnic użyto elementów typu shell. Do analizy wykorzystano specjalistyczne oprogramowanie metody elementów skończonych MSC Dytran pozwalające na symulacje procesów szybkozmiennych. Przeprowadzone symulacje numeryczne procesu zderzenia, dla różnych konfiguracji rozwiązań konstrukcyjnych, pozwoliły na dogłębne zapoznanie się z charakterem deformacji barierek drogowych. Wybrane przypadki modeli numerycznych zostały zweryfikowane w sposób doświadczalny, co pozwoliło na kompleksową analizę wytrzymałością całej konstrukcji energochłonnej podczas zderzenia. Najmniejszą wartość impulsu opóźnienia posiada bariera SP-01. Jest to spowodowane złożonym sposobem odkształcenia konstrukcji wynikłym ze zginania i skręcania (przez zastosowanie wysięgnika) słupka. Tak duża energochłonność spowodowana jest mimośrodowością układu wynikłą z mimośrodowości spowodowanej długim łącznikiem. Otrzymane wyniki posłużą jako wytyczne do opracowania metodyki badania tego typu struktur i będą mogły być wykorzystywane w dalszych pracach badawczych w zakresie zwiększenia poziomu bezpieczeństwa w transporcie drogowym.