1. |
Opiela K.C., Zieliński T.G., Dvorák T.♦, Kúdela Jr S.♦, Perforated closed-cell aluminium foam for acoustic absorption,
APPLIED ACOUSTICS, ISSN: 0003-682X, DOI: 10.1016/j.apacoust.2020.107706, Vol.174, pp.107706-1-17, 2021Streszczenie: Closed-cell metal foams are lightweight and durable materials resistant to high temperature and harsh conditions, but due to their fully closed porosity they are poor airborne sound absorbers. In this paper a classic method of drilling is used for a nearly closed-cell aluminium foam to open its porous interior to the penetration of acoustic waves propagating in air, thereby increasing the wave energy dissipation inside the pores of the perforated medium. The aim is to investigate whether it is possible to effectively approximate wave propagation and attenuation in industrial perforated heterogeneous materials with originally closed porosity of irregular shape by means of their simplified microstructural representation based on computer tomography scans. The applied multi-scale modelling of sound absorption in foam samples is confronted with impedance tube measurements. Moreover, the collected numerical and experimental data is compared with the corresponding results obtained for perforated solid samples to demonstrate a great benefit coming from the presence of an initially closed porous structure in the foam. Słowa kluczowe: closed-cell metal foams, perforation, sound absorption, microstructure effects, dissipated powers Afiliacje autorów:
Opiela K.C. | - | IPPT PAN | Zieliński T.G. | - | IPPT PAN | Dvorák T. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) | Kúdela Jr S. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) |
| | 100p. |
2. |
Schabowicz K.♦, Jóźwiak-Niedźwiedzka D., Ranachowski Z., Kúdela Jr S.♦, Dvorák T.♦, Microstructural characterization of cellulose fibres in reinforced cement boards,
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2018.01.018, Vol.18, No.4, pp.1068-1078, 2018Streszczenie: The microscopic analysis of the different cellulose fibre cement composites is presented. The observations of the fibres in optical microscope in transmitted light and in scanning electron microscope are described. The micro computed tomography (micro-CT) and SEM were used to determine the distribution of the fibres in the matrix. The investigated fibre cement boards were produced by extrusion process and panels were cured in natural conditions. The main goal of the research was application of different microscopic methods to analyze the fibres distribution as a result of a different methods of their production. Micro-CT was used for 3D visualization of fibres distribution in three different fibre cement boards. It was possible to determine the average diameter of the fibres and their concentration using the high-resolution mode of micro-CT scanning procedure. Finally, a procedure which can be applied as a useful tool for analysis of the different procedures used in production of fibre cement boards is described. This procedure can be successfully used in the quality control system of cellulose fibre distribution in cement composites Słowa kluczowe: Cellulose fibre reinforced cement boards, Microstructure, Fibre distribution, X-ray microtomography, SEM-EDS analysis Afiliacje autorów:
Schabowicz K. | - | Wroclaw University of Science and Technology (PL) | Jóźwiak-Niedźwiedzka D. | - | IPPT PAN | Ranachowski Z. | - | IPPT PAN | Kúdela Jr S. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) | Dvorák T. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) |
| | 30p. |
3. |
Ranachowski Z., Schabowicz K.♦, Gorzelańczyk T.♦, Kúdela Jr S.♦, Dvorák T.♦, Visualization of Fibers and Voids Inside Industrial Fiber Concrete Boards,
Material Science & Engineering International Journal, ISSN: 2574-9927, DOI: 10.15406/mseij.2017.01.00022, Vol.1, No.4, pp.1-4, 2018Streszczenie: Fiber cement boards (FCB) microstructure and methods of fabrication are described. The method of X-ray microtomography in application for investigating of FCB microstructure is presented. The cellulose fibers constituting the remarkable reinforcement of the FCB are colorless and too small to be seen applying the standard optical methods. The X-ray microtomography method however enabled the authors to realize three goals within the investigation of the properties of FCB. The length and shape of the fibers could be assessed on specimens' cross-sections. Applying the pseudo 3D visualization it was possible to visualize the cracked regions inside the specimen volume. The case of non-uniform fibers distribution in respect to the board thickness which was impossible to recognize applying the standard visual inspection, was also performed by merging the multiple cross-section images into a single graph Afiliacje autorów:
Ranachowski Z. | - | IPPT PAN | Schabowicz K. | - | Wroclaw University of Science and Technology (PL) | Gorzelańczyk T. | - | Wroclaw University of Science and Technology (PL) | Kúdela Jr S. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) | Dvorák T. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) |
| |
4. |
Żołek N., Ranachowski Z., Ranachowski P., Jóźwiak-Niedźwiedzka D., Kúdela Jr S.♦, Dvorák T.♦, Statistical assessment of the microstructure of barite aggregate from different deposits using x-ray microtomography and optical microscopy,
ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0104, Vol.62, No.2, pp.697-702, 2017Streszczenie: Two different barite ore (barium sulfate BaSO4) specimens from different localizations were tested and described in this paper. Analysis of the microstructure was performed on polished sections, and on thin sections using X-ray microtomography (micro-CT), and optical microscopy (MO). Microtomography allowed obtaining three-dimensional images of the barite aggregate specimens. In the tomograms, the spatial distribution of the other polluting phases, empty space as well as cracks, pores, and voids – that exceeded ten micrometers of diameter-were possible to visualize. Also, the micro-CT allowed distinguishing between minerals of different density, like SiO2 and BaSO4. Images obtained and analyzed on thin sections with various methods using the optical microscopy in transmitted light delivered additional information on the aggregate microstructure, i.e. allow for estimation of the different kinds of inclusions (like the different density of the minerals) in the investigated specimens. Above methods, which were used in the tests, completed each another in order to supply a set of information on inclusions' distribution and to present the important differences of the barite aggregate specimens microstructure. Słowa kluczowe: barite ore, barite aggregate, microstructure, optical microscopy, thin sections analysis, X-ray tomography Afiliacje autorów:
Żołek N. | - | IPPT PAN | Ranachowski Z. | - | IPPT PAN | Ranachowski P. | - | IPPT PAN | Jóźwiak-Niedźwiedzka D. | - | IPPT PAN | Kúdela Jr S. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) | Dvorák T. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) |
| | 30p. |
5. |
Schabowicz K.♦, Ranachowski Z., Jóźwiak-Niedźwiedzka D., Radzik Ł.♦, Kúdela Jr S.♦, Dvorák T.♦, Application of X-ray microtomography to quality assessment of fibre cement boards,
CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2016.02.035, Vol.110, pp.182-188, 2016Streszczenie: In this paper a method of X-ray microtomography (micro-CT) was employed for a direct insight into a microstructure of fibre cement boards of different quality. Four specimens were subjects of examination. Two parameters were determined to characterize the level of compaction of fibres in concrete matrix: mean-square displacement of migrating virtual particles after 500,000 of time steps and a diffusive tortuosity. The results of the investigation had revealed that fibre cement boards differing in density produce different images after processing with micro-CT method. The effect of microstructure tightening due to saturation using dying agent was also detectable. Słowa kluczowe: Fibre cement boards, Delamination of fibres, Computational modelling, X-ray microtomography Afiliacje autorów:
Schabowicz K. | - | Wroclaw University of Science and Technology (PL) | Ranachowski Z. | - | IPPT PAN | Jóźwiak-Niedźwiedzka D. | - | IPPT PAN | Radzik Ł. | - | inna afiliacja | Kúdela Jr S. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) | Dvorák T. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) |
| | 40p. |
6. |
Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Dąbrowski M., Kúdela Jr S.♦, Dvorák T.♦, The determination of diffusive tortuosity in concrete specimens using X-ray microtomography,
ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2015-0140, Vol.60, No.2, pp.1115-1119, 2015Streszczenie: The paper presents a method of pore connectivity analysis applied to specimens of cement based composites differing in water to cement ratio. The method employed X-ray microtomography (micro-CT). Microtomography supplied digitized three-dimensional radiographs of small concrete specimens. The data derived from the radiographs were applied as an input into the application based on the algorithm called ‘random walk simulation’. As the result a parameter called diffusive tortuosity was established and compared with estimated porosity of examined specimens.
Artykuł prezentuje metodę wyznaczania parametru charakteryzującego intensywność połączeń mikroporów w zastosowaniu do próbek kompozytów z matrycą cementową, różniących się stosunkiem wodnocementowym. Metoda bazuje na wynikach badań z zastosowaniem mikrotomografii rentgenowskiej. Analizowano zdigitizowane zestawy danych, opisujące trójwymiarową reprezentację mikrostruktury niewielkich próbek wykonanych z betonu. Przygotowane w ten sposób skany mikrostruktury zastosowano jako dane wejściowe wprowadzone do oprogramowania wykorzystujacego algorytm ‘przypadkowo migrujących cząstek wirtualnych’. W ten sposób wyznaczono parametr mikrostruktury znany jako krętość dyfuzyjna. Parametr ten porównano z porowatością obserwowaną wyznaczoną dla zbadanych próbek przy wykorzystaniu analizy jasności voxeli w analizowanych próbkach. Słowa kluczowe: X-ray tomography, concrete microstructure, diffusive tortuosity Afiliacje autorów:
Ranachowski Z. | - | IPPT PAN | Jóźwiak-Niedźwiedzka D. | - | IPPT PAN | Ranachowski P. | - | IPPT PAN | Dąbrowski M. | - | IPPT PAN | Kúdela Jr S. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) | Dvorák T. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) |
| | 30p. |
7. |
Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Rejmund F., Dąbrowski M., Kúdela Jr S.♦, Dvorák T.♦, Application of X-ray microtomography and optical microscopy to determine the microstructure of concrete penetrated by carbon dioxide,
ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.2478/amm-2014-0245, Vol.59, No.4, pp.1451-1457, 2014Streszczenie: In the paper two advanced methods for testing cement based composites are described and compared. These are X-ray microtomography and optical microscopy. Microtomography supplies three-dimensional images of small concrete specimens. In the tomograms all cracks, pores and other voids and inclusions, that exceed a few micrometers, are shown. Such visualisation can become a valuable tool for analysis of the basic material properties. Images obtained on thin sections and analysed with various methods on optical microscopes supply additional information on material microstructure that cannot be obtained in tomograms. For example it is relatively easy to determine zone penetrated by CO2 ingress. These two methods, presented on examples of tests, complete each another in order to supply a set of information on composition and defects of tested composite materials. Słowa kluczowe: cement matrix composites, concrete deterioration, X-ray tomography, microscopic analysis, concrete microstructure Afiliacje autorów:
Ranachowski Z. | - | IPPT PAN | Jóźwiak-Niedźwiedzka D. | - | IPPT PAN | Ranachowski P. | - | IPPT PAN | Rejmund F. | - | IPPT PAN | Dąbrowski M. | - | IPPT PAN | Kúdela Jr S. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) | Dvorák T. | - | Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK) |
| | 25p. |