Wyniki wyszukiwania - Biblioteka Nauki

1

Application of Acoustic Emission Method to Investigate Aluminosilicate Bodies During Firing Process

100%

Ranachowski P.

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2000

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tom Vol. 21

229-235

EN

Presented paper covers the continuation of the author's investigations printed in M&QA '1999 [1]. Comprehensive exploration of the topie consists of extended temperature range up to 1000 degrees centigrade, improved discussion of the results of Acoustic Emission (AE) measurements and corresponding methods. The results of the investigation were presented using classic composition porcelain body as an example. Composition components of the body, simplified sequence of temperature transitions, applied measunng setup and the results using comparative techniques DTA,TG/DTG and dilatometric method, were described.

2

Acoustic Emission in Testing of Selected Ceramic Bodies

100%

Ranachowski P.

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1999

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tom Vol. 20

217-225

EN

The paper presents a new acoustic method for monitoring of phase and polymorphous conversions during sintering of ceramic raw materials. A high-alumina electrotechnical porcelain, used in manufacturing of insulators, was chosen as an example of the application of this method. The conversions occurring in ceramic raw materials have been discussed in detail. The measuring system and the analysed descriptors of acoustic emission have been described. The results of investigation on both phase and polymorphous transitions in the range of 20 - 700°C, obtained using acoustic emission method, have been presented and compared with the results of study on DTA, TG, and the coefficient oflinearthermal expansion a. Good accordance of the results obtained by the mentioned methods and the AE descriptors was found.

3

Celowość zastosowania porcelany wysokoglinowej rodzaju 130 do produkcji izolatorów najwyższych napięć

63%

Ranachowski J. , Ranachowski P.

Prace Naukowe Instytutu Podstaw Elektrotechniki i Elektrotechnologii Politechniki Wrocławskiej. Konferencje

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2000

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tom Vol. 37, nr 12

93-98

PL

W prezentowanej pracy przedstawiono parametry techniczne oraz strukturę porcelany rodzaju 130 na tle tworzyw rodzaju 110 112 i 120 pod kątem zastosowania do produkcji izolatorów elektroenergetycznych. Analizowano parametry mające wpływ na jakość i niezawodność. Zajmowano się głównie wytrzymałością krótkotrwałą, metodą oceny wytrzymałości długotrwałej oraz parametrami na te wytrzymałości wpływającymi. Porównano budowy strukturalne tworzyw rodzaju 120 i 130 pod kątem wyjaśnienia wpływu budowy na odporność na rozwój mikropęknięć, co warunkuje trwałości wyrobów.

EN

The purpose of this work was to compare parameters and suitability of porcelain materials C 120 and C 130. The comparison was based on structural measurements and examining the short and long-term mechanical strength; the Weibull distribution of mech. strength of long-rod insulators, which are used for overhead high voltage lines, is also presented. The service life of insulators made of C 130 material was estd. on the basis of overstress probe. It is proved that parameters of C 130 material are much better than those of other materials.

4

Urządzenie do precyzyjnych pomiarów prędkości propagacji fal ultradźwiękowych i współczynnika tłumieni w tworzywach ceramicznych.

63%

Ranachowski P. , Rećko W. M.

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2003

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tom R. 54, nr 4

15-18

5

Odporność termomechaniczna tworzywa kordierytowego stabilizowanego mulitem badana metodą emisji akustycznej

63%

Ranachowski P. , Ranachowski Z.

Prace Naukowe Instytutu Budownictwa Politechniki Wrocławskiej. Konferencje

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1999

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tom Vol. 75, nr 26

147-154

PL

Opisano potrójny układ równowagi fazowej MgO-Al2O3-SiO2 w odniesieniu do powstawania tworzywa kordierytowego. Opisano skład surowcowy masy oraz zastosowaną technologię produkcji kordierytu stabilizowanego mulitem. Tworzywo przeznaczone było na podkładki spawalnicze. Przeanalizowano budowę strukturalną czerepu, właściwości mechaniczne oraz odporność na szok termiczny w zakresie temperatur 150-320 o C. Próbki poddane trójpunktowemu naprężeniu mechanicznemu, uprzednio szokowane, badano metodą emisji akustycznej. Podano wyniki badań oraz wykres współczynnika emisji akustycznej z wyznaczeniem parametrów degradacji wytrzymałości termomechanicznej tworzywa.

EN

The paper describes a raw materials composition and manufacturing technology of cordierite material, stabilised by mullite, applied to manufacturing of welding washers. The structural composition of the pot material, its mechanical properties, and resistance to thermal shock within the range 150-320 0C were analysed. Shocked samples, submitted to three-point mechanical stress, have been investigated by acoustic emission method. The results of studies, and a course of acoustic emission coefficient as a function of load, was presented, assigning a point of strength degradation.

6

The analysis of the influence of the thermal shocks on acoustic emission signal generated in cordierite ceramics

63%

Ranachowski Z. , Ranachowski P.

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tom Vol. 25, no. 1

67-72

EN

The paper describes a raw materials composition and manufacturing technology of cordierite material, applied to manufacturing of welding backing strips. The resistance of the cordierite specimens to thermal shock within the range of 150-320°C was analysed. Shocked samples, submitted to three - point mechanical stress, have been investigated by acoustic emission method. The results let the authors to conclude that there is a correlation between the Acoustic Emission (AE) signals parameter, describing the AE activity during the loading and the stage of material degradation caused by the applied thermal shock.

7

Ultradźwiękowe pomiary porowatości technicznych tworzyw glinokrzemianowych

63%

Ranachowski P. , Malecki I.

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tom Vol. 19

239-250

EN

The general relations between the elastic modules and velocity of longitudinal acoustic wave ' continuous loss-less medium were used as the reference point for the analysis. The attenuat ition of the ultrasound wave was expressed by the density o fthe cross-sections caused by the inclusions. The porous material was treated as the continuous substitute medium with the elastic modules being the function of the properties of the carrier non-porous material and the parameters of the porosity. The following parameters were taken into account: the degree of porosity as ratio of the porous and carrier materials densities, the distribution o fpores size, the shape of t spheroidal por es. The velocity o fpropagation of the longitudinal acoustic wave was presented by the complex formula related with the elastic properties of the substitute medium and the carrier material. The influence of the attenuation on the wave propagation velocity was neglected. Several ceramics were investigated. The parameters of the porosity were evaluated by the optical,m icroscopic observation. The elastic modules of the nonporous carrier materials are well known. The velocity of ultrasound wave was measured with the usual acoustical methods. The results of the measurements confirm the theoretical investigation concerning the influence of the porosity on the mechanical properties of the ceramics.

8

Experimental methods of determination of short and long-term mechanical strength of ceramic insulators

63%

Rejmund F. , Ranachowski P.

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tom Vol. 46, iss. 1

131-139

EN

The subject of this paper are the properties of ceramic insulators responsible for transmission of mechanical stresses due to their construction and destination. Taking into account the information about failure of the insulators, the effect of electrical stresses imposed on the insulator structure by the electric field can be neglected. In view of this fact, our considerations concern the parameters characterising short and long-term mechanical strengths and the method of forecasting the minimal time to the mechanical failure.

9

Ocena porowatości porcelany na podstawie analizy wyników pomiarów wyładowań niezupełnych

51%

Morańda H. , Ranachowski P. , Mościcka-Grzesiak H.

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tom R. 86, nr 11b

251-253

PL

Artykuł opisuje rezultaty próby powiązania porowatości porcelany z wybranymi parametrami opisującymi wyładowania niezupełne generowane w niej przy napięciu przemiennym. Z przeprowadzonych badań wynika, że w porcelanie istnieje zależność między udziałem procentowym porów o różnej wielkości a ładunkiem i częstością pojawiania się impulsów wyładowań niezupełnych.

EN

The article describes results of the attempt to find out the correlation between porosity of porcelain and selected parameters describing partial discharges generated under AC voltage. The study shows that there is a correlation between the percentage of different sizes pores and the frequency of PD pulse occurrence.

10

Aparatura akustyczna do oceny jakości, niezawodności i prognozowania trwałości ceramicznych izolatorów elektroenergetycznych

51%

Ranachowski J. , Ranachowski P. , Bertrand J.

Prace Naukowe Instytutu Podstaw Elektrotechniki i Elektrotechnologii Politechniki Wrocławskiej. Konferencje

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2000

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tom Vol. 36, nr 11

101-116

PL

Przedstawiono nowo opracowaną aparaturę do badań akustycznych oraz podstawy teoretycznej budowy i stosowania. Opisane metody ultradźwiękowe dotyczą szczególnego przypadku defektoskopii - wykrywania wad w okutej części izolatorów wspornych. Przedstawiono przykłady defektów tego typu oraz zautomatyzowaną aparaturę do ich wykrywania. Innym przykładem urządzenia diagnostycznego jest urządzenie do precyzyjnego pomiaru czasu przejścia impulsu przez próbki ceramiczne. Jest ono przeznaczone przede wszystkim do pomiaru jednorodności oraz modułów sprężystości tworzyw ceramicznych. Do precyzyjnych pomiarów parametrów mechanicznych materiałów zaprojektowano natomiast i wykonano maszynę wytrzymałościową umożliwiającą badania ze skrajnie małymi prędkościami odkształcania, wyposażoną w detektor emisji akustycznej Urządzenie umożliwia pomiar składowej plastycznej materiału ceramicznego.

EN

Newly elaborated instrumentation to acoustic measurements is presented as well as a theoretical basis for its application. The ultrasonic methods are described as applied to a particular branch of defectoscopy - detection of defects in lower parts of station post insulators. The examples of such defects and automatic detecting instrumentation are presented. The next example of applying propagation of acoustic waves is an instrument for precise measurement of time of impulse passing. The main function of this device is measurements of homogeneity and elastic constants of the materials tested. For precise measurements of mechanical parameters of ceramic materials a special testing machine was designed and built for tests with extremely low load speeds, equipped with an acoustic emission detector. This instrument enables measuring of elastic components off ceramic materials.

11

Badania elektroporcelany rodzaju 130 pod obciążeniem ściskającym metodami akustycznymi i mikroskopowymi

51%

Ranachowski P. , Rejmund F. , Pawełek A. , Piątkowski A.

Prace Naukowe Instytutu Podstaw Elektrotechniki i Elektrotechnologii Politechniki Wrocławskiej. Konferencje

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2003

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tom Vol. 38, nr 13

31-38

PL

Praca przedstawia wyniki badań mikroskopowych, ultradźwiękowych oraz emisji akustycznej (EA) próbek poddanych rosnącym naprężeniom ściskającym. Przedmiot badań stanowiły kształtki wykonane z porcelany rodzaju 130. Próbki badano metodą ultradźwiękową w celu ustalenia jednorodności strukturalnej oraz dynamicznego modułu Younga tworzywa. Na podstawie pomiarów EA ściskanych próbek wyróżniono kolejne etapy degradacji struktury. Badania mikroskopowe pozwoliły na uwidocznienie parametrów strukturalnych tworzywa przed obciążeniem oraz na poszczególnych etapach rozwoju pęknięć. Badania wykazały inny mechanizm degradacji strukturalnej niż w przypadku typowych tworzyw glinokrzemianowych.

EN

The paper presents the results of microscopic, ultrasound and acoustic emission (AE) measurements of samples subjected to compressive stress. The object of investigation were specimens made of aluminous porcelain, 130 type. The samples were investigated using ultrasonic method to establish their structural homogeneity, to determine the acoustic parameters and Young's modulus of the material. AE descriptors were registered during slow increase of the external force. Basing on the AE measurements, the samples were divided into three groups. Microscopic investigation revealed the structural parameters of the material before and after its loading. The obtained dependences are evidence of different stages of destruction process in porcelain 130 type compared to typical aluminosilicate materials.

12

Acoustic emission probes of foam drainage processes in H2O-C2H5OH-air system with content of detergent triton X-100

51%

Rzeszotarska J. , Rejmund F. , Ranachowski P.

Hydroacoustics

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1997

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tom Vol. 1

317--320

EN

The acoustic emission (AE) of short-lived static foams from non-ionic detergent Triton X-100 in ethanol-water solutions has been investigated. The AE of foam drainage process has shown two different stages of behaviour. The first step up to 80 s was without the appearance of AE signals. During this stage the rearrangement of bubbles has been observed. The next, main stage of drainage process proceeded with a high intensity AE generation. The results suggest that the AE technique gives the direct possibility of foam stability measurement.

13

Mechanical-acoustic study of degradation processes of ceramic structure illustrated by corundum material

51%

Ranachowski P. , Rejmund F. , Pawełek A. , Piątkowski A.

Przegląd Elektrotechniczny

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2008

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tom R. 84, nr 10

252-255

EN

The paper presents the results of microscopic, ultrasonic and acoustic emission (AE) investigations of corundum ceramic material C 799 kind samples, exposed to compressive stress. On the basis of AE measurements of slowly compressed samples, the successive stages of structural degradation have been recognized. Investigations revealed that differences registered for the strength and the mechanical-acoustic characteristics are due to the inhomogeneity of the material in the semi-macro as well as in the micro scale.

PL

W pracy przedstawiono wyniki badań mikroskopowych, ultradźwiękowych oraz emisji akustycznej (EA) próbek tworzywa korundowego (C 799), poddanych wolno narastającemu obciążeniu ściskającemu. Przeprowadzone badania umożliwiły rozpoznanie tekstury tworzywa oraz monitorowanie kolejnych etapów degradacji struktury, aż do całkowitego jej zniszczenia.

14

Acoustic-mechanical and microscopic investigation of corundum material

51%

Ranachowski P. , Rejmund F. , Pawełek A. , Piątkowski A.

Archives of Acoustics

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2007

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tom Vol. 32, No. 4

963--969

EN

This paper presents the results of acoustic emission (AE) measurements of samples under compressive stress. Additional research, concerning structure and parameters of the material, were performed using microscopic and ultrasonic methods. The object of investigation were samples of corundum material C 799 type. The content of alumina in investigated material was equal to 99.7%. The corundum materials demonstrate high mechanical, thermomechanical as well as grindability resistance and find wide application in production of modern technical devices. The aim of study was recognition of stages of degradation processes of the corundum structure. The analysis of AE results pointed out diversified strength and mechanical-acoustic characteristics of particular samples. It was stated during microscopic investigation that the main reason for this effect is due to different grains size and their spatial distribution. The authors consider the abnormal grain growth (AGG) phenomenon as a reason of inhomogeneities of the corundum structures in particular samples. This effect occurs at longer sintering term, especially for fast temperature growth. AGG phenomenon has random character and up to now is not explained in satisfying way.

15

Appliation of Acoustic Emission Method in Puch Press Monitoring

51%

Ranachowski P. , Dębowski T. , Moszczyński L.

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tom Vol. 23

377-388

EN

The authors of this paper analysed Acoustic Emission (AE) signal generated in different stages of punch process. The details of the instrumentation used are described. The experimental part despribes: the influenece of feedstock thickness and hardensss to the intensity of the emmited signal, the changes of AE signal caused by simulated tool abrasive wear and the dependance between the number of razors un multi - element progressive punch on the emitted signal. The possibilities of AE minitoring of punching of thin plates are also duscussed.

16

Measurements of Aluminous Porcelain Under Compression Load

51%

Ranachowski P. , Rejmund F. , Pawełek A. , Piątkowski A.

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tom Vol. 23

363-376

EN

The paper presents the results of microscopic, ultrasound and scoustic emission (AE) measurements of samples subjected to compressive stress. The object of investigations were specimens mede of aluminous porcelain, 120 type, which finds wide application in electrical engineering. The samples were invastigated using ultrasonic method to establish wheir structural homogeneity and to determine the acoustic parameters and the elastic constants of the material. AE descriptors were registered during slow increase of the external force, at stopped loading and during unloading. Basing on the AE measurements of the compressed samples two stages of structure degradation were distinguished: the preliminary and the subcritical stage. Complex microscopic investigations enabled to reveal the structural parameters of the material before its loading, after the subcritical stage of the developement microcracks. The recorded dependences are evidence of deviation from the brittle-elastic model of the damage of a eramic material.

17

New ultrasonic equipment for non-destructive diagnostics of ceramic insulators in place of exploitation

51%

Ranachowski P. , Rejmund F. , Zienkiewicz B.

Prace Naukowe Instytutu Podstaw Elektrotechniki i Elektrotechnologii Politechniki Wrocławskiej. Konferencje

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2004

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tom Vol. 40, nr 15

169-176

EN

The paper presents designed and experienced in IFTR PAS apparatus - acoustic instrument for materials parameters investigation of special assignment. The presented set-up is mainly expected to serve for ultrasonic measurements of long-rod insulators in use on site. The main object of research are insulators after long period of exploitation, showing high degree of material ageing process advancement. Diagnostics of such elements requires definite parameters of work of a sending-receiving unit, piezoelectric transducers of special construction, elaboration of proper methodology of ultrasonic measurements along with criteria of the object classification. Presented equipment is the result of many years experience of non-destructive acoustic research of long-rod ceramic insulators. This equipment was specially adopted for the field tests on the overhead lines and stations. The composition of the set-up, principle of its work and the calibration procedure with standardized blocks were described. The measurements of post insulator SWZPAK-110 type from 1976 year illustrate possibilities of application of the set-up. A microscopic structural analysis was used as comparative method. Correlation between the microstructure of the porcelain and parameters of ultrasonic wave propagation was established. The investigation proved possibility to employ the apparatus for diagnostic measurements of the polymer and hybrid insulators.

18

Examination of the Properties of Samples from Glass-Epoxy Core Rods for Composite Insulators Subjected to DC High Voltage

51%

Wieczorek K. , Jaroszewski M. , Ranachowski P. , Ranachowski Z.

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tom 63

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nr 3

19

Photoacoustic Transformation in Naturally Gyrotropic Media with Opposite Electromagnetic Waves Interaction

51%

Kozhushko V. , Mityurich G. , Ranachowski P.

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1999

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tom Vol. 20

131-134

20

Acoustic Emission Data on Mechanism Fracture of Unidirectional Fiber Reinforced Composites

51%

Leksowskij A. , Abdumanonov A. , Pilecki S. , Ranachowski P.

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1999

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tom Vol. 20

135-141

EN

The investigation of fiber's break process was carried out by acoustic emission method under tensile loading of AL-B and carbon fibers reinforced composites. The experiment has shown that final act of macrofacture is preceding by sequence of single breaks, which time interval are shortened impetuously. The analysis interval of time sequence point out that the fiber breaks are correlated and the distribution of local stress by relaxation process. It is established that Weibull's distribution of B-fibers strength is not homogeneous and has characteristic modes. lt is shown that Zweben's model on determination of strength of unidirectional fibers reinforced composites gives satisfactory agreement with an experiment under taking into account lowering of coefficient stress concentration on fiber, neighboring to broken (at the expense of relaxation effect) and using the parameter of width distribution not on the whole, but without weak one.