Wyniki wyszukiwania - Biblioteka Nauki

1

Analysis of dynamic loads of the armoured personnel carrier crew during frontal crash

100%

Hryciów Z.

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tom Vol. 19, No. 4

223-230

EN

The work describes chosen problem connected with using of armoured personnel carriers (APC) in the frame of stabilisation and peacekeeping mission. The new type of tasks appears: ramming obstacles such as fences, entry gates, light engineering obstacles and also pushing other vehicles aside the road in order to obtain trafficability. The main threat in such situation is a risk of serious injury of soldiers inside vehicle. The lack of a crumple zone increases a value of acceleration acting on the crew. In the work models of driver and crew member seats used in the APC were showed. To the tests a Hybrid III 50th male dummy model in a seated position were used, which is a good representation of the average population of men. To the modelling LS-DYNA software was applied. The work shows the numeric test results. Behaviour of the dummies during the impact on both the driver and crew member were presented. To assess a risk of injury standard indicators of crash test were used, including: maximum value of the head acceleration, the criterion HIC and the maximum values of the forces and moments in the neck. The distributions of these parameters were presented. Results of simulation indicated that velocity and location of dummies has large influence on levels of dynamic loads. To further research is proposed to take into consideration models of dummy with additional equipment of soldiers (e.g. a helmet, a weapon, a bullet-proof jacket).

2

The assessment of the influence of selected passive safety systems on the level of dynamic loads of soldiers during collision

100%

Hryciów Z.

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tom Vol. 20, No. 3

161--168

EN

The work describes chosen problem connected with using of armoured personnel carriers (APC) in the frame of military operations. The soldiers inside the APC are exposed to dynamic loads and shock which are, among other things, an effect of collision with other vehicle or terrain obstacles. In military vehicles, which design is based on a rigid frame or integral body, there is no technical solution to mitigate the effects of a crash. The only applicable means of protection against the effects of collisions are lap belts and helmet designed to protect the head. Preliminary research shows that this kind of equipment is not sufficient. In the work an assessment of the influence of chosen solutions of safety belts and helmets on dynamic loads of carrier’s crew during collision with a rigid obstacle are presented. In simulation researches the HYBRID III dummies models have been used and calculations were carried out in LS-DYNA system. The work shows the numeric test results. Behaviour of the dummies during the impact on both the driver and crew member were presented. To assess a risk of injury standard indicators of crash test were used, including: maximum value of the head acceleration and the maximum values of the forces and moments in the neck. The distributions of these parameters were presented. The assessment of applied passive safety systems was made from the point of view of treat to soldiers inside a carrier.

3

Problematyka zarządzania cyklem życia wyrobów obronnych w NATO

63%

Hryciów Z. , Ławniczak S.

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tom Nr 30

181--188

4

Optimization of characteristic of suspension elements of power pack unit in motor vehicles

63%

Borkowski W. , Hryciów Z.

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tom Vol. 13, No. 4

121-128

EN

In the paper chosen questions relating to the influence of power pack unit vibrations on dynamics of vehicle are described, particularly from comfort of drive point of view. The problems of power pack fastening to frame of vehicle using rubber-metal vibration isolators are introduced. Advantages and defect of this type of solution are passed. In the paper the questions of vibration isolators selection with optimum characteristic the special attention are dedicated. The possible to use method of optimization of spring and damping characteristic this type of elements is introduced. The object of investigations, its physical model and nonlinear mathematical model is described as well as acting on it loading conditions. The task of optimization is formulated in frames which the criterion of optimization and objective function is passed, the set of decision variables is specified as well as limitations put on these variables. The method of determinate the characteristic of elastic elements was passed. In the paper the examples results of simulating investigations are put — the accelerations of power pack unit as well as appointed optimum characteristic.

PL

W pracy opisano wybrane zagadnienia dotyczące wpływu drgań bloku napadowego na dynamiką pojazdu, a w szczególności na komfort jazdy. Przedstawiono problematykę zamocowania bloku napędowego do ramy pojazdu przy użyciuwibroizolatorów gumowo-metalowych. Podano zalety i wady tego typu rozwiązania. W pracy szczególną Wagę poświęcono zagadnieniom doboru wibroizolatorów o optymalnych charakterystykach. Przedstawiono możliwą do zastosowania metodę optymalizacji, służącą kształtowaniu charakterystyk sprężysto-tlumiących tego typu elementów. Opisano obiekt badań, jego model fizyczny oraz nieliniowy model matematyczny, a także działające na niego wymuszenia. Sformulowano zadanie optymalizacji, w ramach którego podano kryterium optymalizacji, funkcję celu, j tprecyzowano zbiór zmiennych decyzyjnych oraz podano ograniczenia nałożone na te zmienne. Podano także metodę wyznaczania charakterystyk elementów sprężystych. W pracy zamieszczono przykładowe wyniki badań symulacyjnych -przebiegi przyspieszeń bloku napędowego oraz wyznaczoną charakterystykę optymalną.

5

The experimental tests on the friction coefficient between the leaves of the multi-leaf spring considering a condition of the friction surfaces

51%

Hryciów Z. , Krasoń W. , Wysocki J.

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tom Vol. 20, no. 4

682--688

EN

In this study are presented the results of the simulation tests of the friction pairs occurring between the spring leaves while considering a condition of the mating surfaces and an impact of the velocity of their mutual dislocation on the values of the friction coefficients. It has been proposed a methodology in respect of a determination of the coefficients of the static and kinetic friction. Two kinds of the specimens have been prepared for the tests, which have been cut out from a spring leaf of the prototype spring – they have created the model friction pairs. The condition of the specimen surface and their selected mechanical properties have been evaluated. During the experimental tests have been considered: four sliding velocities, four variants of the surface conditions and two values of the normal load. The tests of the friction pairs have been performed at the laboratory stand for measuring the friction force. The results of the tests have been presented in a form of the time courses of friction force, graphs and tabular summaries of the friction coefficients. It has been conducted a comparative analysis of the results in order to determine an influence of the test results on the values of the determined friction coefficients. The proposed research conditions are approximate to the typical operating conditions of the road vehicles.

PL

W pracy przedstawiono wyniki badań symulacyjnych węzłów tarcia występujących pomiędzy piórami resoru, z uwzględnieniem stanu powierzchni współpracujących oraz wpływu prędkości ich wzajemnego przemieszczania, na wartości współczynników tarcia. Zaproponowano metodykę wyznaczania współczynników statycznych i kinetycznych tarcia. Do badań przygotowano dwa rodzaje próbek, które wycięto z pióra resoru prototypowego - tworzyły one modelowe pary cierne. Oceniono stan powierzchni próbek i wybrane właściwości mechaniczne. W badaniach eksperymentalnych uwzględniono: cztery prędkości poślizgu, cztery warianty stanu powierzchni oraz dwie wartości obciążenia normalnego. Badania par ciernych wykonano na stanowisku laboratoryjnym do pomiaru siły tarcia. Wyniki badań przedstawiono w postaci przebiegów czasowych siły tarcia, wykresów i zestawień tabelarycznych współczynników tarcia. Wykonano analizę porównawczą wyników w celu określenia wpływu warunków badań, na wartości wyznaczonych współczynników tarcia. Zaproponowane warunki badań są zbliżone do typowych warunków eksploatacyjnych pojazdów drogowych.

6

Influence of the shape of the explosive charge on blast profile

51%

Hryciów Z. , Borkowski W. , Rybak P. , Wysocki Z.

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tom Vol. 21, No. 4

169--176

EN

When an explosive charge is fired, the nature and mass of the explosive are the only parameters of importance usually considered. The shape however, also plays a major role in the effect of an explosive charge. Knowledge of shape effect can be important before the use of the explosive (in order to create a maximum effect with a given mass of explosive), or in post-explosion damage assessment. The shape effect however is only significant within a certain range from the charge. At longer distance, the produced blast wave tends to be spherical. The shock wave parameters studied in this work are the peak overpressure and the first positive impulse. A series of numerical test has been performed in order to determine the range of influence of the charge shape. Different locations of initiation were compared. A hemispherical charge was point detonated at its centre whereas a cylindrical shape was detonated at the centre of an upper or lower plane. Numerical simulations of near field burst were conducted using LS-DYNA software. During numerical tests a pressure fields were determined for different shapes of explosive charges as well as the pressure waveforms at points located 1000 mm from a centre. Additionally, reference pressure history curves from LOAD_BLAST_ENHANCED procedure were calculated.

7

Studies on possibilities of increasing the impact resistance of KTO Rosomak

51%

Borkowski W. , Rybak P. , Hryciów Z. , Wysocki J.

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tom Vol. 19, No. 4

101-110

EN

Military vehicles are mostly designed in order to provide effective execution of tasks in regions of expected actions and operation conditions. During execution of projects, resulting from participation in peace making and stabilization missions, military vehicles are subject to the impact of various mines and improvised explosives. In many cases, the explosive material mass included in the explosive charges affecting the vehicles significantly exceeds the values specified in standards defining the required protection levels assumed at the design stage. The above determines the search for additional shields or energy-absorbing elements reducing the effects of such influence. Information concerning design solutions is usually classified or very limited. Majority of companies dealing with that issue provides information concerning the scope of their business, highlighting the military area thus high efficiency of their protective solutions, possibly presenting a general outline of a particular solution. This paper presents selected results of analyses and studies being carried out and obtained results of solutions to problems included in the study tasks covering a considered subject. Proposed solutions of protective shields against mines and IED for the KTO Rosomak are presented.

8

Research on the effectiveness of the innovative protective structure for vehicles

38%

Borkowski W. , Rybak P. , Hryciów Z. , Starczewski L. , Gmitrzuk M. , Szcześniak K.

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tom Vol. 22, No. 1

29--36

EN

This article presents results of the research on developed innovative protective structure for vehicles. The fundamental objective of executed work was to check the correctness of assumed assumptions, shape and geometry of the solution and configuration of components that affect the protective effectiveness during the impact of the explosive. In order to reach that goal, both model tests and experimental tests were carried out. The experimental tests were carried out on the real object. Significant information about the level, directions and nature of affecting dynamic loads were obtained as well as information about their impact on particular structure elements. The MES numerical model of the research object has been developed in LS-Dyna system. Special emphasis was placed on the mapping of complex geometry, configuration of components and their interactions. Test calculations were carried out and then the resistance calculations were made. As a load, generating post-explosion impact wave, the load imposed by normative requirements concerning the way of explosive arrangement as well as the shape and weight. The analysis of obtained results of the experimental and numerical tests allows for high evaluation of effectiveness of proposed solution.