PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Testing the attenuation capabilities of ballistic shields made using 3D printing
Wierzbicka Karolina, Paszula Józef, Gieleta Roman, Komorek Zenon
Materiały Wysokoenergetyczne
|
2022
|
T. 14
58--75
EN
The paper describes a study of the blast wave energy absorption capabilities of sandwich ballistic shields. A comparative study of multilayer structures containing cores with different elementary cell shapes in their structure was performed. Energy-absorbing layers of different types of polymers were made. Tests of static and dynamic properties of the ballistic shield layers were carried out. The attenuation capabilities of these shields were determined by measuring the force acting on the base substrate of the shield.
PL
W pracy zaprojektowano i wykonano osłony balistyczne typu sandwich oraz przeprowadzono badania zdolności absorbowania energii fali podmuchowej. Przeprowadzono porównawcze badania struktur wielowarstwowych zawierających w swojej strukturze rdzenie o różnych kształtach komórek elementarnych. W badaniach przygotowano warstwy wykonane z różnych typów materiałów. Przeprowadzono badania właściwości statycznych i dynamicznych zaprojektowanych warstw osłon balistycznych. Zdolność tłumiącą wytypowanych osłon określano poprzez pomiar siły działającej na podstawę osłony.
2
Content available The influence of temperature on the damping characteristic of hydraulic shock absorbers
Hryciów Zdzisław, Rybak Piotr, Gieleta Roman
Eksploatacja i Niezawodność
|
2021
|
Vol. 23, no. 2
346--351
EN
This paper presents the results of bench-tests and calculations assessing the influence of temperature on the performance of a two-pipe hydraulic shock absorber. The shock absorber prepared for the tests was cooled with dry ice to a temperature corresponding to that associated with the average winter conditions in a temperate climate. The temperature range of the shock absorber during testing was ensured via equipping it with a thermocouple and monitoring it with a thermal imaging camera. During testing, the shock absorber was subjected to kinematic forces of a selected frequency with two different, fixed displacement amplitudes. The results of the tests showed a direct correlation between the decrease of component resistance at lower temperatures. The rate of change in resistance was higher at lower temperatures. It was also found that the energy dissipated in one shock cycle decreased linearly with an increasing temperature. Finally, a method for determining the ideal use temperature of the shock absorber for the assumed operating conditions was also presented.
3
Content available Effect of Test Velocity on the Specific Energy Absorption under Progressive Crushing of Composite Tubes
Ryzińska Grażyna, Gieleta Roman
Advances in Science and Technology. Research Journal
|
2020
|
Vol. 14, no 2
94--102
EN
The paper presents the results of the compression tests for carbon-epoxy composites in order to assess the amount of energy absorbed depending on the process velocity and content of axial fibres. Two types of prepreg (UD 200 g/m2 and woven 160 g/m2) were used to prepare the specimens with a diameter of 20 mm and a height of 34 mm. The specimens were subjected to compression under various speed conditions (static, dynamic and SHPB tests). The calculated specific energy absorption values showed a 50–60% decrease with increasing process velocity and depending on the type of specimens architecture. The highest energy values were absorbed by the specimens with the highest share of axial fibres in the sample.
4
Content available remote Research on influence of TiSi(N) reflective coating thermal resistance on energy absorption of fireproof textile coupled with auxetic fabric
Miedzińska Danuta, Stankiewicz Michał, Gieleta Roman, Marszałek Konstanty
Engineering Transactions
|
2019
|
Vol. 67, iss. 2
253--270
EN
The research presented in the paper deals with the improvement of firemen protective clothing. The proposed modification of the special textile PROTON is based on the application of TiSi(N) nanocomposite reflective layer, which improves the thermal resistance of the coated material. The second improvement deals with the implementation of auxetic textile into the protective clothing structure. Such material is characterized with the very good blast wave resistance. In the paper both phenomena were studied. The results of thermal resistance of coated and not coated PROTON shown that the application of such structure decreased the temperature acting behind the textile and the application of the auxetic textile significantly increased the PROTON resistance to gas impact. Also the advantages of coupling both improvement methods were discussed, because of the negative influence of high temperature on auxetic behaviour.
5
Content available remote Numerical modelling of post-ground subsystem in road safety barrier crash tests
Klasztorny Marian, Nycz Daniel Bronisław, Dziewulski Paweł, Gieleta Roman, Stankiewicz Michał, Zielonka Karol
Engineering Transactions
|
2019
|
Vol. 67, iss. 4
513--534
EN
A new analytical algorithm for determining the elastoplastic parameters for soft, medium and hard plastic cohesive soils, corresponding to *MAT_005_SOIL_AND_FOAM material model available LS-Dyna FE code, was formulated. The numerical modelling of the post-soil subsystem, applicable in the modelling of road safety barrier crash tests using this material model of the roadside dehydrated ground, was developed. The methodology was presented on the example of a Sigma-100 steel post partly driven into the soil and subjected to a static flexural-torsional test using a horizontal tensioned rope. The experimental validation of the numerical modelling and simulation was carried out on the testing site at the Automotive Industry Institute, Warsaw, Poland. The simulations were carried out for numerical models with soil solid elements with reduced integration (ELFORM_1) and full integration (ELFORM_2). The simulation results are in the form of graphs of the rope tension vs. displacement of the upper measurement point of the post and in the form of deformation of the post-soil system. It was shown that the validation experiment was carried out on the post embedded in hydrated soft plastic cohesive soil.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.