Wyniki wyszukiwania - Biblioteka Nauki

1

Materiał inteligentny do zastosowania w strukturach lotniczych

100%

Skalski P.

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2014

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tom nr 6

9577--9582

PL

Właściwości materiałów inteligentnych mogą być kontrolowane za pomocą temperatury, wilgoci, pola elektrycznego bądź magnetycznego, współczynnika pH bądź przez zmianę naprężeń. Wiele materiałów inteligentnych zostało wynalezionych ponad 30 lat temu, ale ich rozwój przez ostatnie trzy dziesięciolecia pozwolił na ich wiele różnych zastosowań. Morfing w zastosowaniach lotniczych cieszy się coraz większym zainteresowaniem, ze względu na możliwość zwiększenia wydajności i efektywności lotu w szerokim zakresie warunków lotu. Praca zawiera wprowadzenie nowego materiału inteligentnego (poszycia magnetoreologicznego) w zastosowaniu do struktur morficznych.

EN

Smart materials have properties that can be altered by temperature, moisture, electric or magnetic fields, pH, and stress. Many “smart” materials were invented more than 30 years ago, but their development and improvement over the past three decades has led to new, more varied uses of these adaptable materials. The morphing technology on aircraft has found increased interest over the last decade because it is likely to enhance performance and efficiency over a wider range of flight conditions. The work presents an introduction of a new smart material (a magnetorheological skin) for use in morphing structures.

2

Mechanical characterization of the interface between a shape memory alloy fiber and a resin epoxy matrix

84%

Thiebaud F. , Gabry B. , Lexcellent C.

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tom Vol. 46, iss.3/4

290-314

EN

The aim of this paper is to characterize the interface between a shape memory alloy wire (SMA) and a epoxy resin matrix. Herę we present the effect of various surface treatments applied to SMA NiTi wires on the ąuality of the interface fiber/matrbc. First, the use of the fiber pull-out test allows to separate the different treatments into two families: on the one hand, decohesion of the wire; on the other hand, rupture of the wire before debonding. The data given by the pull-out tests are not sufficient to differenciate the surface treatments which cause the breaking of the wire rather than the interfacial debonding of the fiber/matrbc. In order to complete our research, a topographical study is carried out on different wires. It allows us to extract the parameters which characterize the vertical distribution of roughness and its morphology. The analysis of these experimental results leads to the choice of the surface treatment which will guarantee higher interfacial stresses. Among all the wires studied, we choose the prestrained wire. The quantitative aspect of this study allows us to know better the evolution of the different parameters of roughness, and thus to guide our research works to an optimal surface treatment of the wire.

3

Polymer matrix composite materials reinforced by Tb0.3Dy0.7Fe1.9 magnetostrictive particles

84%

Dobrzański L. A. , Tomiczek A. , Tomiczek B. , Ślawska-Waniewska A. , Iesenchuk O.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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tom Vol. 37, nr 1

16-23

EN

Purpose: The goal of this work was to describe manufacturing process of polymer matrix composite materials reinforced by Tb0.3Dy0.7Fe1.9 particles and to observe changes of physical properties (magnetic properties and magnetostriction) of samples with randomly oriented magnetostrictive particles in epoxy matrix and with aligning these particles in the matrix during fabrication process. Design/methodology/approach: Polymer matrix composite materials reinforced by the Tb0.3Dy0.7Fe1.9 magnetostrictive particles fabricating method was developed during the investigations, making it possible to obtain materials with good physical properties. The influence of the concentration of the Td0.3Dy0.7Fe1.9 particles on magnetic and magnetostrictive properties was estimated. Metallographic examination of powder’s morphology as well as EDS and XRD analysis and observations the structure of composite materials were made. Findings: The influence of magnetic particle alignment is observed in the magnetic and magnetostriction responses. The magnetostrictive response improves when the magnetic particles are oriented in magnetic fields and reaches approximately 184 ppm for oriented composite materials with 25% volume fraction of Td0.3Dy0.7Fe1.9 particles. Practical implications: For potential applications in technological devices, such as sensors and actuators, it is desirable to form composite systems by combining magnetostrictive phases with matrix, in order to have giant magnetostrictive effect and, at the same time, to reduce disadvantages of monolithic material. Originality/value: The originality of this work is based on manufacturing process, especially of applying magnetic alignment for ordering Td0.3Dy0.7Fe1.9 particles during polymerization of epoxy matrix.

4

Magnetorheological characterisation of carbonyl iron based suspension

84%

Kciuk M. , Kciuk S. , Turczyn R.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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tom Vol. 33, nr 2

135-141

EN

Purpose: The main aim of this article was to present the investigation results of magnetorheological fluids (MR) composed of carbonyl iron (CI) particles and analyse their flow behaviour in terms of the internal structure formation by a control of applied external magnetic field. The morphology, magnetic properties, sedimentation stability, and magnetorheological properties of the examined MR fluids were studied. Design/methodology/approach: Model MR fluid was prepared using silicone oil OKS 1050 mixed with carbonyl iron powder CI. Furthermore, to reduce sedimentation Aerosil 200 was added as stabilizers. In the purpose to determine the properties of the analyzed fluids the sedimentation and dynamic viscosity were investigated. Findings: Dynamic viscosity of investigated magnetorheological fluids rapidly and reversibly change in response to the applied external magnetic field. Moreover added particles of fumed silica inhibited sedimentation of carbonyl iron particles. Research limitations/implications: MR fluids with excellent properties can be applied in various fields of civil engineering, safety engineering, transportation and life science. They offer an outstanding capability of active control of mechanical properties. But there are no systematic published studies of factors affecting the durability of MR fluids and devices. There is very little information on the effects of exposing different MR fluids to temperature, for this reasons further efforts are needed in order to obtain even better results. Originality/value: The investigation results are reliable and could be very useful both for designers and the practitioners of many branches of industry.

5

Long-time stability of shape memory actuators for pedestrian safety system

84%

Strittmatter J. , Gümpel P. , Zhigang H.

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tom Vol. 34, nr 1

23-30

EN

Purpose: Pedestrian safety systems play an increasing significant role to reduce injuries and fatal casualties caused by accidents. One automotive safety system for pedestrian protection is the bonnet lifting system. Using shape memory alloys (SMA) the existing systems could be simplified, performing the same function through new mechanisms with reduced size, weight and costs. A drawback for the use of SMA in such safety systems is the lack of material knowledge concerning the durability of the switching function. This paper gives an introduction to existing bonnet lifting systems for pedestrian protection, describes the use of quick changing SM actuators and presents the testing facilities and some results of the study concerning the long-time stability of the tested NiTi-wires. Design/methodology/approach: A large number of NiTi-wires was trained, exposed up to four years at elevated temperatures and tested regarding their phase change temperatures, times and strokes. Findings: It was found out that Ap-temperature is shifted towards higher temperatures with longer exposing periods and higher temperatures. However, in the functional testing plant a delay in the switching time could not be detected. Research limitations/implications: For future works it is suggested that more NiTi-specimens at longer ageing periods should be tested, stress should also be applied by a constant load and the functional testing plant should be further optimized. Practical implications: It can be concluded, that the use of quick changing SM actuators in safety systems could simplify the mechanism, reduce maintenance and manufacture cost and should be insertable also for other automotive applications. Originality/value: This paper gives some answers concerning the long-time stability of NiTi-wires that were missing till now. With this knowledge the number of future automotive applications using SMA can be increased.

6

Test setup for examination of magneto-mechanical properties of magnetorheological elastomers with use of a novel approach

84%

Bocian M. , Kaleta J. , Lewandowski D. , Przybylski M.

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2016

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tom Vol. 16, no. 3

294--303

EN

This paper presents an experimental setup aiming at evaluating the magneto-mechanical and damping properties of the thermoplastic magnetorheological elastomer (MRE). The idea of the system is to create controllable conditions similar to those present in a vehicles and other mechanical constructions and to make it possible to determine parameters only relating to the MRE material itself. The test stand is based on four samples stimulated with highly effective Halbach arrays. The upper plate of the test stand is excited with use of a modal shaker to assure a constant impact force value during each test. This enables control of impact character and allows automation of the test stand. The last section of this paper presents preliminary test conducted to find the resonance frequency dependence on the impact force of the system for a constant value of magnetic field. The results indicate non-linear behavior of the material and therefore exclude use of the simple Kelvin-Voight model based approach for damping properties determination, that is a commonly used model for description of different materials.

7

The concept of multifuncional wall – an energy system integrated in a single wall

67%

Figaszewski J. , Sokołowska-Moskwiak J.

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tom Vol. 10, no. 1

5--10

EN

In 1981 Mike Davis proposed a new design of the glass wall, which he called a polyvalent wall that would dynamically respond to changing environmental conditions. The idea of an inter-active component in a building envelope has become a source of inspiration for the proponents of external wall concepts. The proposed designs are important because they apply principles of multifunctionality based on cooperation between the wall layers and the dynamic reaction of changing external and internal thermal conditions. The multilayer wall, therefore, plays a major role in the thermal shielding of a building and is a key component in energy efficiency. And the use of new construction materials the wall functionality has been expanded. This application has also expanded the role of a wall in the process of energy management of a building. A non-transparent wall can produce electricity, supply heat from solar radiation, absorb, store and distribute heat. It can be responsible for stabilizing room temperatures. The cooperation between individual layers also has an impact on energy efficiency and on the microclimate of a given building. This paper will present different ways of energy activation in external walls with a special focus on the photovoltaic panels/modules (PV), the transparent insulation (TIM) and phase change materials (PCM). New materials can be included in the partition structure in different configurations such as a single or a bi-material component for improving thermal effects.

PL

W 1981 roku Mike Davis opracował teoretyczny model szklanej przegrody, nazwanej ścianą poliwalentną, która reagowała na zmiany warunków środowiska wewnętrznego i zewnętrznego. Idea interaktywności w obudowie budynku stała się źródłem inspiracji dla wielu współczesnych rozwiązań zewnętrznych przegród. Przyjmują one jej podstawowe cechy: wielofunkcyjność, współzależność jej poszczególnych warstw i reagowanie na zmienność warunków termicznych otoczenia. W kategoriach energetycznych podstawową rolą ściany wielowarstwowej jest ochrona termiczna budynku. Dzięki nowym materiałom budowlanym poszerza się zakres pełnionych przez nią funkcji i zwiększa się jej udział w procesach gospodarowania energią w budynku. Nieprzezierna przegroda staje się wytwornikiem energii elektrycznej, uczestniczy w pozyskaniu ciepła z promieniowania słonecznego, pochłania ciepło, gromadzi je, uwalnia i rozprowadza w swojej strukturze, odpowiada za stabilizację temperatury w pomieszczeniach. Łączy ona zatem w sobie funkcje dwóch podstawowych typów przegród: przeszklonych fasad i pełnych ścian wielowarstwowych. Równocześnie poszczególne jej warstwy podejmują współpracę w celu podniesienia sprawności energetycznej budynku i poprawy mikroklimatu wnętrza. Środkiem doskonalenia przegrody są nowe rozwiązania materiałowe zaliczane do pasywnych i aktywnych systemów energetycznych. Artykuł przybliża różne sposoby aktywizacji energetycznej wielowarstwowych ścian zewnętrznych ze szczególnym uwzględnieniem ogniw fotowoltaicznych, izolacji transparentnej TIM i materiałów zmiennofazowych PCM. Nowe materiały mogą być wkomponowane w przegrodę w różnych konfiguracjach: pojedynczo lub razem, dla zwiększenia efektów energetycznych.

8

Mechanical Properties of Auxetic and Conventional Polypropylene Random Short Fibre Reinforced Composites

67%

Uzun M.

Fibres & Textiles in Eastern Europe

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2012

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tom Vol. 20, no. 5 (94)

70--74

EN

In this study, prior to the production of composites, auxetic and conventional polypropylene (PP) fibres were produced by the melt spinning technique. The fibres were tested and analysed in terms of Poisson's ratio, linear density, elongation at break and tenacity. The auxetic and conventional PP stable fibre reinforced composites were fabricated by the hand lay up method. Several mechanical properties of the composites were examined, including tensile strength, Young's modulus, elongation at break, energy absorption, impact velocity and damage size. SEM analysis was also conducted to identify microscopic changes to the overall composite structures. It was found that the auxetic fibre reinforced composites (7.5% and 10%) had the highest tensile strength and the auxetic fibre reinforced composite (5%) had the highest Young's modulus. The highest energy absorption was observed for the composite made with 10% auxetic fibre loading.

PL

Włókna polipropylenowe konwencjonalne i auksetyczne były produkowane poprzez przędzenie ze stopu z zastosowaniem wytłaczarki. Włókna były badane biorąc pod uwagę masę liniową, wytrzymałość właściwą, wydłużenie przy zerwaniu oraz znak współczynnika Poissona. Po dodaniu włókien do kompozytu badano otrzymany produkt określając parametry mechaniczne m.in. wytrzymałość na zerwanie, moduł Younga, wydłużenie przy zerwaniu, absorpcję energii, wielkość zniszczenia przy określonej prędkości udaru. Przeprowadzono również badanie mikroskopowe SEM dla określenia struktury wewnętrznej. Stwierdzono, że największa wytrzymałość miały kompozyty wzmocnione polipropylenowymi włóknami auksetycznymi 7,5% i 10%, natomiast najwyższy moduł Younga miały kompozyty zawierające 5% włókien auksetycznych. Największą absorpcję energii zaobserwowano dla kompozytów wzmacnianych 10% włóknami auksetycznymi.

9

Experimental and numerical studies of MR damper with prototype magnetorheological fluid

67%

Kciuk S. , Turczyn R. , Kciuk M.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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tom Vol. 39, nr 1

52-59

EN

Purpose: Results of experimental studies of a prototype magnetorheological damper at various magnitudes of control current as well as the manner of modelling electromagnetic phenomena occurring in the damper are presented in this paper. Design/methodology/approach: Model MR fluid was prepared using silicone oil OKS 1050 mixed with carbonyl iron powder CI. Furthermore, to reduce sedimentation, as stabilizers was added Aerosil 200. The observations of the surface morphology of carbonyl iron and fumed silica were carried out using Digital Scanning Electron Microscope SUPRATM25 ZEISS. The effect of magnetic field on magnetorheological fluid is modelled by the finite element method. Findings: The presented model meets the initial criteria, which gives ground to the assumption about its usability for determining the dynamics properties of mechanical systems, employing the finite element method using ANSYS software. Research limitations/implications: The elaborated model can be use for modelling the semi active car suspension dynamics. Originality/value: The actual-non-linear characteristics of magnetisation identified experimentally were used as the values of relative magnetic permeability of the piston housing material. The possibility of application, e.g. real characteristics of material magnetisation and faster and faster calculation machines make possibility the creation of more precise models and more adequate ones to reality.

10

Zależność pomiędzy oporem elektrycznym a odkształceniem przy ściskaniu kompozytów cementowych zbrojonych włóknami stalowymi

67%

Teomete E. , Kocyigit O. I.

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tom R. 20/82, nr 4

244--252

PL

Inteligentne materiały konstrukcyjne umożliwiają kontrolę stanu konstrukcji betonowych przy stosunkowo małych kosztach, zapewniając dużą czułość. W pracy przygotowano kompozyty cementowe zbrojone włóknami stalowymi, a ich badania wykazały, że opór elektryczny próbek betonowych rośnie z czasem hydratacji. Zbadano właściwości czujnika tensometrycznego złożonego z betonu z włóknami stalowymi, a mianowicie współczynnik czujnika [czułość], liniowość oraz granicę odkształcenia. Współczynnik czujnika w przypadku komercyjnych czujników metalowych wynosi K=2, podczas gdy dla kompozytów cementowych zbrojonych włóknami stalowymi współczynnik ten jest bardzo duży i wynosi K=156. Tak więc, czujniki betonowe są bardziej czułe na odkształcenie niż komercyjne metalowe czujniki tensometryczne. Nawet w przypadku zastosowania powtórnych obciążeń przy znacznych poziomach naprężeń, współczynnik czujnika betonowego pozostaje wysoki, co wskazuje na możliwość ich stosowania jako inteligentnych materiałów konstrukcyjnych.

EN

The smart structural materials are enable to health monitoring of concrete with reduced expenses and high sensitivity. In this study, steel fibre concretes were produced and their examination was showing that their electrical resistance is increasing with the curing age. The measurements possibilities of these sensors, which are gage factor (sensitivity), linearity and strain limit were determined. The gage factor of the commercial metal strain gages is K=2 while gage factor of steel fibre concrete was high, equal K=156. Thus, the steel fibre concretes are much more sensitive to strain than commercial metal strain gages. Even after the repeated loading of concrete samples to considerable stress levels, the gag e factor remains high which shows that the cement composite can be used as a smart structural material.

11

Idee kształtujące innowacyjne wyzwania techniki budowlanej. W poszukiwaniu paradygmatu rozwoju budownictwa

51%

Czarnecki L. , Deja J. , Furtak K. , Halicka A. , Kapliński O. , Kaszyńska M. , Kruk M. , Kuczyński K. , Szczechowiak E. , Śliwiński J.

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tom nr 7

28--33

PL

Innowacyjne wyzwania techniki budowlanej to myśl przewodnia 63. Konferencji Naukowej Komitetu Inżynierii Lądowej i Wodnej Polskiej Akademii Nauk oraz Komitetu Nauki Polskiego Związku Inżynierów i Techników Budownictwa. W artykule omówiono wybrane zagadnienia wyznaczające uwarunkowania innowacji: użytkownik; środowisko; wymagania podstawowe; efektywność energetyczna. Wskazano inżynierię materiałów budowlanych oraz inżynierię przedsięwzięć budowlanych jako obszary o największym potencjale innowacyjnym w połączeniu z konstrukcjami budowlanymi i przegrodami jako szczególnym elementem budowlanym. Zwrócono uwagę na ciągłość rozwoju budownictwa z tendencją do występowania zmian skokowych. Podkreślono znaczenie zintegrowanego kształtowania obiektu budowlanego w celu zapewnienia dalszego rozwoju.

EN

Innovative challenges for construction technology are the keynote of the 63rd Scientific Conference of the Committee for Civil Engineering of the Polish Academy of Sciences and the Scientific Committee of the Polish Association of Civil Engineers and Technicians. The selected issues (dwellers, fundamental requirements, environmental, energy effectiveness) conditioning construction innovations are described in the article. Building Material Engineering and Construction Industry Engineering are shown as fields of the greatest innovation potential. Building constructions and particular construction elements industrial building partitions are considered as the basic beneficiaries of future innovations. The attention is drawn on a continual development of construction industry with tendency to occur momentary jumping change. The significance of the integral building works realization for further progress is stressed.