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Wyszukujesz frazę "materials penetration" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Identification of pierced materials characteristics in the aspect of selected degenerated models
Autorzy:
Jamroziak, K.
Bocian, M.
Tematy:
analysis and modelling
light ballistic shields
materials penetration
degenerated models
identification
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Wydawca:
Instytut Techniczny Wojsk Lotniczych
Powiązania:
https://bibliotekanauki.pl/articles/246167.pdf  Link otwiera się w nowym oknie
Opis:
A number of theoretical problems are discovered in the application of degenerated models in punching process of ballistic shields. Insufficient knowledge of dynamic behaviours of these models based on non-linear complex constitutive materials or combination of mixed rheological Maxwell models with linear elastic elements or dissipative is the main reason of the problems. In the engineering application with the influence of rheological forces the element of mass responsible for force ofinertia in dynamic loads is always applied. Taking the forces into consideration in dynamic analysis the degenerated system is necessary to use. It is also utilitarian goal of materiał properties identification in punching process with the use ofparticle mass (projectile). In this paper, the authors present further results ofresearch in this area. Suppression and dispersion of energy is the crucial phenomena in the punching process of ballistic shields with the use of small arms. Therefore the research presented in the paper concerns systems based on viscotic damping with the dry friction parameter (h). As a result ofthe research influence of h parameter on time and frequency characteristics under impact stress was estimated. Analytic calculations and simulations of the examination were validated by experimental test and measurements. With the basis on the results the final conclusions were formulated.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving the method for determining the dust penetration of textile materials for the human protective equipment manufacture
Autorzy:
Avahumian, A. A.
Zashchepkina, N. M.
Tematy:
dust penetration
textile materials
television information
measuring system
penetracja pyłu
materiały tekstylne
informacja telewizyjna
system pomiarowy
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Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Powiązania:
https://bibliotekanauki.pl/articles/1818823.pdf  Link otwiera się w nowym oknie
Opis:
Purpose: Improving the accuracy of determining the coefficient of dust permeability of textile materials and protective products from them. Design/methodology/approach: The problem solution of human protection from the negative effects of road dust is to improve the quality control procedures of textile materials using modern measurement methods. A methodology has been developed for investigating the dust penetration coefficient of materials based on the use of a television informationmeasuring system (TIMS). Findings: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved, by increasing the accuracy of measurement and determining the patterns of the influence of structure on the permeability of textile materials. Research limitations/implications: Improving methods of quality control of textile materials through the use of modern methods of measuring techniques is by solving an important problem of human protection from the negative effects of road dust. Known methods do not take into account the forceful effect of the airflow on the structure of the test sample, which is essential for textile materials that are easily deformed, which affects the objectivity of the results. Significant inconvenience, complexity, and duration of the test process give a large measurement error. Practical implications: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved. This system allows an increase in the accuracy of measurements by 15%, and the availability of software to increase the speed of displaying the results of investigations on the screen. Originality/value: The main disadvantages of methods and means of determining the dust permeability of textile materials - is the inability to determine the duration and dynamics of the process of dust retention. Known methods do not take into account the force of air flow on the structure of the test sample, which is significant, especially for materials that are easily deformed, which affects the objectivity of the results. Significant inconveniences, complexity and duration of the test process give a large measurement error. A scientific novelty is the development of a modern and completely new method for determining the permeability of textile materials using a television information - measuring system, by increasing the accuracy of measurement and determining the patterns of influence of the structure of textile materials on dust permeability.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przenikanie wodoru do wnętrza obciążonej zmęczeniowo konstrukcji metalowej oraz jego zapobieganie
Hydrogen penetration into the interior of the metal fatigue of the loaded structure and its prevention
Autorzy:
Jamroziak, K.
Jarguliński, W.
Piesiak, S.
Tematy:
obciążenia cykliczne
zmęczenie materiałów
propagacja szczeliny zmęczeniowej
wnikanie wodoru do metali
cyclic loading
fatigue of materials
fatigue crack propagation
penetration of hydrogen to metal
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Wydawca:
Uczelnia Jana Wyżykowskiego
Powiązania:
https://bibliotekanauki.pl/articles/137174.pdf  Link otwiera się w nowym oknie
Opis:
Autorzy opisują zjawisko przenikania wodoru przez powierzchnię metalowej konstrukcji obciążonej cyklicznie w powietrzu przy temperaturze od -40o do +50o. Wodór głownie przenika przez szczeliny zmęczeniowe, gdzie następuje czysta i świeża powierzchnia pękania. Czynnikiem warunkującym istnienie reakcji katalitycznej, w czasie której para wodna ulega dysocjacji na wodór i tlen, jest wodór. Przenika on do wnętrza metalu, a tlen tworzy związki powierzchniowe. Jednym ze sposobów ochrony przed wnikaniem wodoru z pary wodnej jest nanoszenie powłok ochronnych z tworzyw sztucznych. Na podstawie analizy literatury oraz badań własnych opisano i przytoczono zapobieganie wnikaniu wodoru do konstrukcji metalowej.
The authors describe the phenomenon of hydrogen penetration through the surface of the metal structure cyclically loaded in air at a temperature of from -400 to +500. Hydrogen passes through the slit mainly fatigue, where the clean and fresh fracture on the surface appear. The factor that determines the existence of a catalytic reaction at the time the steam is dissociated into hydrogen and oxygen is hydrogen. It penetrates into the interior of the metal and oxygen forms surface compounds. One way to protect against the penetration of hydrogen from water steam is the use of plastic coatings. Based on the analysis of literature and own studies the way to prevent the penetration of hydrogen into the metal structure was described.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy balance modelling of high velocity impact effect on composite plate structures
Autorzy:
Al-Waily, M.
Jaafar, A.M.
Tematy:
energy balance
high velocity impact
composite materials
penetration
contact force
contact time
bilans energetyczny
uderzenie z dużą prędkością
materiały kompozytowe
penetracja
siła nacisku
czas kontaktu
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Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Powiązania:
https://bibliotekanauki.pl/articles/2175757.pdf  Link otwiera się w nowym oknie
Opis:
Purpose: In many military applications, composite materials have been used because of their high velocity impact resistance that helps absorption and dispersion energy. It is therefore used in armour and vehicles, aircraft and spacecraft that are subjected to impact of various shapes and velocities. Design/methodology/approach: In the theoretical part, the absorption energy equation for the sample was established by constructing an energy balance equation consisting of five types of energies, it is the compressive energy in the first region (the impact region), the tensile energy in the first region, the tensile energy in the second region, the energy of the shear plugging and the friction energy. Findings: It was found in the experiments that the tensile stress value increased by increasing the volume fraction of fibres to the polyester, and the value of compressive stress decreased. Also manufactured different types of impact samples with dimensions (20*20 cm2 ) and deferent thickness. The results were an increase in the amount of energy absorbed by increasing the ratio of the fibre to the polyester. It is found that the greatest effect in the equation of energy balance is the shear plugging energy, in which the value of the energy absorbed reached 38% of the total energy. And in the second degree friction energy, in which the value of the energy absorbed reached 27% of the total energy. while the other energies are relatively small but with important values, except for the tensile energy in the second region, the Kevlar-Polyester (40-60)%, so that the increase was more than four times the previous case. Research limitations/implications: Three types of reinforcing fibres were used: Kevlar, Carbon and Glass fibres with a matrix material as polyester. Six samples are made for tensile and compression testing, Kevlar-Polyester (30-70)%, Carbon-Polyester (30-70)%, Glass-Polyester (30-70)%, Kevlar-Polyester (40-60)%, Carbon-Polyester (40-60)% and Glass-Polyester (40-60)%. Practical implications: On the experimental part, experimental work tests were carried out to determine the mechanical properties of the samples such as tensile and compression tests as well as conducting the natural frequency test conducting the impact test by bullet to identify the effects and penetration incidence and compare this with the theoretical results. Originality/value: In this research high velocity impact is used with a bullet it diameter 9 mm, mass of 8 g, and a semi-circular projectile head with a specific velocity ranging from 210-365 m/s. The effect of the impact is studied theoretically and experimentally. The elastic deformation is increased for increasing the ratio of the fiber to the polyester and the depth of penetration is decreasing. The hybrid sample is affected in absorption energy and decreasing the penetration. Finally calculated for penetration behaviour theoretically and experimentally for different composite materials and comparison for the results calculated.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Budownictwo z gliny i słomy- wstępna ocena wybranych aspektów trwałości
Straw-clay construction – preliminary assessment of selected aspects of sistainability
Autorzy:
Backiel-Brzozowska, B.
Tematy:
naturalne materiały budowlane
domy ekologiczne
budownictwo z gliny
budownictwo ze słomy
mrozoodporność
odporność na wnikanie wody
natural building materials
ecological homes
straw-clay walls
frost resistance
water penetration resistance
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Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Powiązania:
https://bibliotekanauki.pl/articles/400088.pdf  Link otwiera się w nowym oknie
Opis:
Celem pracy jest wskazanie możliwości zastosowania tradycyjnych, ekologicznych materiałów budowlanych – gliny i słomy – do budowy współczesnych jednorodzinnych budynków mieszkaniowych. Przedstawiono genezę budownictwa naturalnego z gliny i słomy. Wyjaśniono podstawowe technologie konstruowania ścian oraz przedstawiono wybrane parametry techniczne przegród wykonywanych w technologii straw-bale. Następnie zaprezentowano wyniki badań nad wybranymi aspektami trwałości przegród z gliny i słomy, przeprowadzone w ramach pracy inżynierskiej wykonanej pod nadzorem autorki niniejszej pracy. W badaniach wykorzystano dwa rodzaje próbek przygotowanych w technologii glinosłomobitki (z gliny ciężkiej z dodatkiem słomy) oraz w technologii straw-bale. Wykazano możliwość uzyskania dobrej mrozoodporności gliny z dodatkiem słomy oraz możliwość skutecznej poprawy odporności na wnikanie wody za pomocą łatwych do wykonania i tanich powłok malarskich.
The aim of this work is to show the possibility of a return to the traditional construction of walls from clay and straw in contemporary building construction characterized by high functional requirements. The introductory part summarizes the roots of natural building with clay and straw. It explains the basic technologies of building with clay and presents selected technical parameters of partitions made in the technology of straw-bale. Then, the results of preliminary tests on selected aspects of the sustainability of partitions made of clay and straw, carried out within the framework of engineering work done under the supervision of the author of this work. The tests were performed under the two types of specimens prepared with different technologies - heavy clay with the addition of straw and straw-bale. It has been shown that it is possible to obtain a good frost resistance of clay with the addition of straw. Also the resistance of water penetration can be effectively improved with easy to implement and low-cost coatings.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deposition and Resuspension of Selected Aerosols Particles on Electrically Charged Filter Materials for Respiratory Protective Devices
Autorzy:
Makowski, K.
Tematy:
electrostatic filter materials
respiratory protective devices
deposition
penetration
filtration
aerosols
dust
aerosol electrostatic charge
ochrona przed pyłami
ochrona przed zanieczyszczeniem
materiały filtracyjne
materiały na środki ochrony indywidualnej
elektryczność statyczna
aerozole
ochrony układu oddechowego
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Wydawca:
Centralny Instytut Ochrony Pracy
Powiązania:
https://bibliotekanauki.pl/articles/90111.pdf  Link otwiera się w nowym oknie
Opis:
The primary aim of the study was to analyse the non-steady state of filtration for selected electrostatic filter materials designed for use in respiratory protective devices. The obtained results showed that the filtration process in electrostatic filters was dependent in the main on the following factors: type of the filter material, electrostatic field strength of the material, and the charge of the aerosol. To a lesser degree the filtration process depended on the sign of the charge and the relative humidity of the air. A significant correlation was found between the increase in the penetration and the decrease in reathing resistance while the filter was being loaded. The effect of resuspension (tearing off and re-deposition of dust agglomerates inside the filter) on the filtration process very significant. It was also observed that under certain conditions electrostatic filter materials lost their protection properties.
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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