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Wyszukujesz frazę "damping properties" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
Damping properties vs. structure fineness of the high-zinc aluminum alloys
Autorzy:
Krajewski, W. K.
Haberl-Faerber, K.
Buras, J.
Krajewski, P. K.
Powiązania:
https://bibliotekanauki.pl/articles/380214.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wysokocynkowy stop aluminium
rozdrobnienie ziarna
właściwości tłumiące
współczynnik tłumienia
high zinc aluminum alloys
grain refinement
damping properties
damping coefficient
Opis:
The subject of this study is the presentation of relation between the degree of structure fineness and ultrasonic wave damping coefficient for the high-zinc aluminium alloys represented in this study by the sand mould cast alloy Al - 20 wt% Zn (AlZn20). The studied alloy was refined with a modifying (Al,Zn)-Ti3 ternary master alloy, introducing Ti in the amount of 400 pm into metal. Based on the analysis of the initial and modified alloy macrostructure images and ultrasonic testing, it was found that the addition of (Al,Zn)-Ti3 master alloy, along side a significant fragmentation of grains, does not reduce the coefficient of ultrasonic waves with a frequency of 1MHz.
Źródło:
Archives of Foundry Engineering; 2012, 12, 3; 63-66
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Grain Refinement and Feeding Quality on Damping Properties of the Al-20Zn Cast Alloy
Autorzy:
Krajewski, W. K.
Faerber, K.
Krajewski, P. K.
Powiązania:
https://bibliotekanauki.pl/articles/380999.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-zinc aluminium alloy
grain refinement
feeding quality
damping properties
wysokocynkowy stop aluminium
rozdrobnienie ziarna
właściwości tłumiące
Opis:
The paper presents relationships between the degree of structure fineness and feeding quality of the Al – 20 wt.% Zn (Al-20 Zn) alloy cast into a mould made from sand containing silica quartz as a matrix and bentonite as a binder, and its damping coefficient of the ultrasound wave at frequency of 1 MHz. The structure of the examined alloy was grain refined by the addition of the refining Al-3 wt.% Ti – 0.15 wt.%C (TiCAl) master alloy. The macrostructure analysis of the initial alloy without the addition of Ti and the alloy doped with 50-100 ppm Ti as well as results of damping experiments showed that the structure of the modified alloy is significantly refined. At the same time, its damping coefficient decreases by about 20-25%; however, it still belongs to the so called high-damping alloys. Additionally, it was found that despite of using high purity metals Al and Zn (minimum 99,99% purity), differences in the damping coefficient for samples cut from upper and bottom parts of the vertically cast rolls were observed. These differences are connected with the insufficient feeding process leading to shrinkage porosity as well as gases present in metal charges which are responsible for bubbles of gas-porosity.
Źródło:
Archives of Foundry Engineering; 2018, 18, 2; 209-214
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of glycerol on the properties of coconut oil cake reinforced poly(lactic acid)
Wpływ glicerolu na właściwości poli(kwasu mlekowego) wzmocnionego makuchami z oleju kokosowego
Autorzy:
Raj, Sachin Sumathy
Chellapandian, Thiruvasagam
Nanjappan, Balakrishnan
Powiązania:
https://bibliotekanauki.pl/articles/2088268.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
poly(lactic acid)
copra
glycerol
mechanical properties
thermal properties
noise damping properties
poli(kwas mlekowy)
makuchy oleju kokosowego
glicerol
właściwości mechaniczne
właściwości termiczne
właściwości tłumiące hałas
Opis:
The effect of the addition of 10–25 wt% coconut oil cake (COC) on the properties of poly(lactic acid) (PLA) was studied. PLA/COC (80/20) composite showed better mechanical properties and higher thermal stability than PLA. Glycerol used as a plasticizer further improved tensile and flexural mechanical properties, as well as the impact strength and the ability to suppress noise.
Zbadano wpływ dodatku 10–25% mas. makuchów z oleju kokosowego (COC) na właściwości poli(kwasu mlekowego) (PLA). Kompozyt PLA/COC (80/20) wykazywał lepsze właściwości mechaniczne i wyższą stabilność termiczną niż PLA. Glicerol zastosowany jako plastyfikator dodatkowo poprawił właściwości mechaniczne przy rozciąganiu i zginaniu, a także udarność i zdolność do tłumienia hałasu.
Źródło:
Polimery; 2022, 67, 2; 61--66
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Grain Size on the Mechanical Damping Behavior of Aluminum
Autorzy:
Jang, Haneul
Choi, Kwangmin
Shin, Jaehyuck
Bae, Donghyun
Choi, Hyunjoo
Powiązania:
https://bibliotekanauki.pl/articles/352557.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al
tensile properties
damping behavior
grain size
Opis:
An understanding of the fundamental correlation between grain size and material damping is crucial for the successful development of structural components offering high strength and good mechanical energy absorption. With this regard, we fabricated aluminum sheets with grain sizes ranging from tens of microns down to 60 nm and investigated their tensile properties and mechanical damping behavior. An obvious transition of the damping mechanism was observed at nanoscale grain sizes, and the underlying causes by grain boundaries were interpreted.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 475-479
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
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:
Extending stability limits by designed-in damping
Autorzy:
Daghini, L.
Archenti, A.
Osterlind, T.
Powiązania:
https://bibliotekanauki.pl/articles/99943.pdf
Data publikacji:
2013
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
high damping interface
cutting stability
operational dynamic properties
machine tool design
Opis:
With advances in material technology come challenges to productivity. New materials are, in fact, more difficult to machine with regards to tool wear and especially machine tool stability. This paper proposes to extend the stability limits of the machining system by enhancing the structures damping capability. The aim of the research work presented here is to introduce a unified concept based on the distribution of damping within the machining system components exploiting the dynamic properties of the existing joints. To maintain a high level of static stiffness, it was chosen to adapt hydrostatic clamping systems to the tools. Damping is designed in the structure via high damping interfaces (HDI), intentionally introduced interfaces where the damping ratio is enhanced by introduction of viscoelastic polymer metal composites between the two metallic surfaces composing the interface. In this paper HDI are introduced at two joints, between tool and turret and between turret and lathe. The tests show that the designed-in damping is effective and allows extending the stability limits of the machining system. The implementation of designed-in damping allows the end user to select the most suitable parameters in terms of productivity avoiding the hassle of tuning the devices, having to acquire a deep knowledge in structural dynamics or having to use additional control systems. In addition to this, the enhanced machine tool system becomes less sensitive to stability issues provoked by difficult-to-machine materials or even fluctuations of the work material properties that might occur in everyday production processes.
Źródło:
Journal of Machine Engineering; 2013, 13, 1; 37-48
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Viscoelastic Characterization of Different Solid Rocket Propellants Using the Maxwell Spring-Dashpot Model
Autorzy:
Shekhar, H.
Kankane, D. K.
Powiązania:
https://bibliotekanauki.pl/articles/358207.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
damping coefficient
Maxwell model
rocket propellants
spring constant
tensile test
viscoelastic properties
Opis:
A single spring and a single dashpot in series was utilized to simulate the stress-strain curve for different classes of solid rocket propellants, namely extruded double base propellants (EDBP) and composite propellants (CP), in the uniaxial tensile mode in a constant rate of travel machine. The propellant behaves as a viscoelastic material and invariably exhibits stress relaxation, which cannot be simulated by elastic mechanical property parameters. In order to generate a complete stress-strain curve of a solid rocket propellant under tensile testing, different classes of solid rocket propellants were evaluated and the stress-strain curve generated was modelled using the single spring-single dashpot Maxwell fluid model. Using two constants, called the spring constant (K) and the damping factor (D), it was possible to generate a complete stress-strain curve. Mathematical formulation gives the stress (σ) - strain (ε) relation as….[wzór]. Additionally the physical nature of the spring constant resembles that of the elastic constant and the damping coefficient gives the contribution of the viscous part of the load bearing capacity of solid rocket propellants. The development of a general mathematical formulation, the calculation of constants for different classes of propellants and insight into the viscoelastic nature of propellants are the main themes of this article. For all classes of propellants, two ratios are defined. The first is a dimensionless parameter 'H', which is the ratio of the spring constant to the initial elastic modulus. The second is the ratio of the damping coefficient to the spring constant depicted by parameter 'S'. The spring constant is higher than the initial elastic modulus and the value of 'H' is always higher than 1. For brittle propellants (extruded double base propellants, EDBPs, with a high elastic modulus), the spring constant is numerically very close to the spring constant (H is around 1.75). As the ductility (percentage elongation) of the solid rocket propellants increases (from cartridge loaded composite propellants, CLCPs, to case-bonded composite propellants, CBCPs), the value of parameter 'H' also increases (H ~ 10 for CP). For EDBPs the parameter 'S' is smaller (~ 1.24), but for CLCPs and CBCPs, it is high (S ~ 5 to 8). Both of these ratios are basic properties of the polymeric matrix. The first ratio depicts the departure of the actual stress-strain curve from linearity, while the second ratio is another way of expressing the relaxation time. A higher 'H' indicates a softer and more ductile propellant, while a higher 'S' indicates a shorter relaxation time for the propellant. A lower 'S' indicates that the propellant recovers faster on removal of strain.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 3; 189-199
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on the effect of kinematic viscosity on electron-acoustic cylindrical and spherical solitary waves in a plasma with trapped electrons
Autorzy:
Roy, Subrata
Saha, Sandip
Raut, Santanu
Das, Apurba Narayan
Powiązania:
https://bibliotekanauki.pl/articles/1839840.pdf
Data publikacji:
2021
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
reductive perturbation technique
vortex-like distribution
propagating properties
nonplanar Schamel-Burgers equations
weak damping
propagacja fal
lepkość kinematyczna
metoda perturbacji
Opis:
In this article, using the standard reductive perturbation technique (RPT) to the basic governing equations for plasma comprising stationary ions, cold electrons and hot electrons abiding by vortex-like distribution, nonplanar Schamel Burger (NSB) equations is derived. In order to study the propagating properties of Electron acoustic (EA), progressive wave solution is obtained by employing the weighted residual method (WRM). Most of the observations of the EA wave are limited to the plasma environment where the effects of viscosity, collisions, ion streaming velocity are totally neglected. In our present observation, propagation of EA waves in a viscous plasma is described considering a weak damping (by adding a Burgers term) due to the inner particle collision and viscosity. Special attention has been given to study the impact of the other physical parameters in wave propagation in the framework of the Schamel Burgers medium.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2021, 20, 2; 65-76
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasound Wave Attenuation of Grain Refined High – Zinc Aluminium Sand-cast Alloys
Autorzy:
Krajewski, W. K.
Buraś, J.
Krajewski, P. K.
Piwowarski, G.
Powiązania:
https://bibliotekanauki.pl/articles/379936.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high zinc Al alloy
sand casting
grain refinement
damping capacity
attenuation
ultrasound wave
strength properties
stop wysokocynkowy
stop Al
odlew piaskowy
rozdrobnienie ziarna
tłumienie
fala ultradźwiękowa
właściwości wytrzymałościowe
Opis:
The paper presents results of measuring attenuation coefficient of the Al-20 wt.% Zn alloy (AlZn20) inoculated with different grain refiners. During experiments the melted alloys were doped with Al-Ti3-C0.15 refining master alloy. Basing on measurements performed by Krautkramer USLT2000 device with 1MHz ultrasound wave frequency it was stated that grain refinement reduces the attenuation coefficient by about 20-25%. However, the examined alloys can be still classified as the high-damping ones of attenuation greater than 150 dB/m.
Źródło:
Archives of Foundry Engineering; 2015, 15, 2; 51-54
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of three different gases and their influence on dynamic properties one-bellow and two-bellows flexible pneumatic coupling
Porównanie trzech gazów i ich wpływu na właściwości dynamiczne sprzęgła pneumatycznego z mieszkami jedno i dwuwarstwowymi
Autorzy:
Krajňák, J.
Grega, R.
Powiązania:
https://bibliotekanauki.pl/articles/196343.pdf
Data publikacji:
2013
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
sprzęgło elastyczne
gaz
mieszek jednowarstwowy
mieszek dwuwarstwowy
hel
propan-butan
współczynnik tłumienia
dynamiczna sztywność skrętna
flexible pneumatic coupling
gas
air
helium
propane-butane
one-bellow
two-bellow
dynamic properties
torsion consistency
damping
experimental measurements
Opis:
The flexible couplings are often used in many various mechanical systems. These flexible couplings have positive attributes for the particular mechanical system and also protect it from damage. At our department, we are interested in that type of couplings, specifically in the flexible pneumatic couplings. The compressed gas is supplied into the couplings. Those couplings use gaseous medium, in this case air. So far we have used air but it is in our department also carried out measurements other gases and helium. The main objective of this article is to determine how various air, helium and propane-butane affects the dynamic properties of flexible pneumatic couplings. We will explore flexible one-bellow and two-bellows flexible pneumatic coupling. Both couplings have been developed in our department.
Sprzęgła podatne są często używane w wielu różnych mechanicznych układach napędowych. Pozytywnie oddziałują one na dany układ mechaniczny, a równocześnie chronią go przed uszkodzeniem. Autorzy niniejszego artykułu w zakładzie, w którym są zatrudnieni zajmują się właśnie tego typu sprzęgłami, a w szczególności podatnymi sprzęgłami pneumatycznymi. Do tych sprzęgieł jest doprowadzany gaz pod ciśnieniem. Głównym celem niniejszego artykułu jest analiza wpływu trzech gazów, takich jak: powietrzne, hel i propan-butan, na charakterystykę dynamiczną dwóch różnych sprzęgieł pneumatycznych. W artykule porównanozatem wykorzystanie różnych gazów przemysłowych, które mają różne właściwości fizyczne. Dodatkowo w celu wykazania różnic pomiędzy dwoma odmianami sprzęgieł pneumatycznych porównane zostały rozwiązania z mieszkami jedno i dwuwarstwowymi. Oba rodzaje sprzęgieł zostały opracowane w zakładzie, w którym pracują autorzy niniejszego artykułu.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2013, 81; 79-84
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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