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Fast continuous in-situ XCT of additively manufactured carbon fiber reinforced tensile test specimens
Glinz, J.; Maurer, J.; Holzleitner, M.; Pace, F.; Stamopoulos, A.; Vopálenský, Michal; Kumpová, Ivana; Eckl, M.; Kastner, J.; Senck, S.
2023 - English
The reinforcement of fused filament fabricated (FFF) components with continuous fibers allows for high versatility in the design of mechanical properties for a specific application’s needs. However, the bonding quality between continuous fibers and the FFF matrix material has high impact on the overall performance of the composite. In a recent study [1], additively manufactured (AM) continuous fiber reinforced tensile test specimens have been investigated regarding the effect of amount and material of the embedded continuous fibers on tensile strength and AM build quality. During these tensile tests, a sudden reduction in tensile stress, which most likely was not related to actual rupture of continuous fibers, was noticeable. Since X-ray computed tomography (XCT) scans were performed only prior to and after the tensile testing, a detailed investigation on the origin of these drops in tensile stress was not possible. Within this work, we will expand upon these findings and present results of fast on-the-fly in-situ investigations performed on continuous carbon fiber reinforced specimens of the same AM build. During these investigations, specimens are loaded under the same conditions while fast XCT scans, with a total scan time of 12 seconds each, were performed consecutively. The resulting three-dimensional image data reveals internal meso- and macro-structural changes over time/strain to find the cause of the aforementioned reduction in tensile stress.
Keywords:
additive manufacturing; composites; X-ray computed tomography; in-situ tensile testing
Available at various institutes of the ASCR
Fast continuous in-situ XCT of additively manufactured carbon fiber reinforced tensile test specimens
The reinforcement of fused filament fabricated (FFF) components with continuous fibers allows for high versatility in the design of mechanical properties for a specific application’s needs. However, ...
Acta Polytechnica CTU Proceedings. Vol. 42 (2023)
Kytýř, Daniel; Doktor, T.; Zlámal, Petr
2023 - English
The YSESM symposium provides a forum for young researchers and engineers, PhD students and students dealing with subjects of experimental mechanics. The Symposium concentrates on current work in all areas of experimental research and its application in solid and fluid mechanics. The topic will particularly concern to: Conventional and Advanced Experimental Methods in Solid and Fluid Mechanics, Non-Destructive Testing and Inspection, Measurements in Material Science, Computer Assisted Testing and Simulation, Engineering Design Simulation, Hybrid Methods, Experimental Techniques – Numerical Simulation, Optical Methods and Image Processing, Measurements in Biomechanics, Sensor Techniques for Micro- and Nano-Applications, Measurement Methods for Forensic Engineering.
Keywords:
experimental mechanics; fluid mechanics; mechanics of solids
Available at various institutes of the ASCR
Acta Polytechnica CTU Proceedings. Vol. 42 (2023)
The YSESM symposium provides a forum for young researchers and engineers, PhD students and students dealing with subjects of experimental mechanics. The Symposium concentrates on current work in all ...
Analyzing stochastic stability of a gyroscope through the stochastic Lyapunov function
Náprstek, Jiří; Fischer, Cyril
2023 - English
The text delves into the application of first integrals in the construction of Lyapunov functions for analyzing the stability of dynamic systems in stochastic domains. It emphasizes the distinct characteristics of first integrals that warrant the introduction of additional constraints to ensure the essential properties required for a Lyapunov function. These constraints possess physical interpretations associated with system stability. The general approach to testing stochastic stability is illustrated using the example of a 3-degrees-of-freedom system representing a gyroscope.
Keywords:
stochastic stability; Lyapunov function; first integral; gyroscope
Available at various institutes of the ASCR
Analyzing stochastic stability of a gyroscope through the stochastic Lyapunov function
The text delves into the application of first integrals in the construction of Lyapunov functions for analyzing the stability of dynamic systems in stochastic domains. It emphasizes the distinct ...
Průzkum Přibyslavské štoly zemním radarem
Válek, Jan; Kotková, Kristýna; Kozlovcev, Petr
2023 - Czech
Byl realizován nedestruktivní průzkum Přibyslavské štoly pomocí zemního radaru. Cílem měření bylo ověření existence případných prostor skrytých pod současným povrchem štoly. Průzkum lokalizoval násyp nad skalním podložím štoly a další nehomogenity. A non-destructive survey of the Přibyslav underground corridor using ground penetrating radar was carried out. The aim of the measurement was to verify the existence of possible structures hidden under the current surface of the corridor. The survey located the backfill above the bedrock of the underground corridor and other changes in the structure.
Keywords:
ground penetrating radar (GPR); cultural heritage; non-destructive testing
Available at various institutes of the ASCR
Průzkum Přibyslavské štoly zemním radarem
Byl realizován nedestruktivní průzkum Přibyslavské štoly pomocí zemního radaru. Cílem měření bylo ověření existence případných prostor skrytých pod současným povrchem štoly. Průzkum lokalizoval násyp ...
Laboratorní mikroskopický průzkum stratigrafie barevných nátěrů na stavebních materiálech budovy Morzinského paláce v Nerudově ulici v Praze 1
Slížková, Zuzana; Náhunková, Pavla; Bauerová, Pavla; Vondráčková, Michaela
2023 - Czech
Stratigrafická analýza barevných nátěrů na fasádě Morzínského paláce v Praze za účelem určení barevnosti fasády pro návrh obnovy a restaurování budovy. Stratigraphic analysis of the color coatings on the facade of the Morzín Palace in Prague in order to determine the color of the facade for the future restoration of the building.
Keywords:
stratigraphy; colored layers; coatings; microscopy
Available at various institutes of the ASCR
Laboratorní mikroskopický průzkum stratigrafie barevných nátěrů na stavebních materiálech budovy Morzinského paláce v Nerudově ulici v Praze 1
Stratigrafická analýza barevných nátěrů na fasádě Morzínského paláce v Praze za účelem určení barevnosti fasády pro návrh obnovy a restaurování budovy....
Výsledky mikroskopické analýzy vzorků malt odebraných z objektů: věž kláštera v Sázavě, Apolinář v Praze
Bauerová, Pavla; Frankeová, Dita; Vondráčková, Michaela
2023 - Czech
omocí elektronového mikroskopu a EDS analýzy byly zkoumány vzorky ze dvou lokalit - vzorek malty z věže kláštera v Sázavě a dva vzorky omítky z objektu Apolinář v Praze (Apolinář – líc, Apolinář – půda). Cílem zkoumání bylo zejména určit druh pojiva omítek a nátěrů na omítce. Ve všech třech analyzovaných vzorcích bylo identifikováno silně hydraulické pojivo. Using an electron microscope and EDS analysis, samples from two locations were examined - a sample of mortar from the tower of the monastery in Sázava and two samples of plaster from the Apolinař building in Prague (Apolinář - face, Apolinář - soil). The aim of the investigation was to determine the type of binder for plasters and coatings on plaster. A strongly hydraulic binder was identified in all three analyzed samples.
Keywords:
microscopy; EDS analysis; mortars
Available at various institutes of the ASCR
Výsledky mikroskopické analýzy vzorků malt odebraných z objektů: věž kláštera v Sázavě, Apolinář v Praze
omocí elektronového mikroskopu a EDS analýzy byly zkoumány vzorky ze dvou lokalit - vzorek malty z věže kláštera v Sázavě a dva vzorky omítky z objektu Apolinář v Praze (Apolinář – líc, Apolinář – ...
Conductive open-cell silicone foam for modulatable damping and impact sensing applications
Preuer, R.; Šleichrt, Jan; Kytýř, Daniel; Graz, I.
2023 - English
Nature has long served as a source of inspiration for the development of new materials, with foam-like structures in fruits such as oranges and pamelos serving as examples of efficient energy dissipation. In this study, we present the synthesis and characterization of a conductive silicone foam for potential impact sensing applications. By blending Sylgard 184 and Carbon Black, we create a highly porous structure capable of dissipating energy and modulating its resistance. To investigate the properties of the foam, we utilized both micro-computer tomography (μCT) and scanning electron microscopy (SEM) imaging techniques. The μCT imaging revealed the intricate pore network of the foam, reminiscent of the complex structure found in natural sponges. SEM imaging allowed for observation of the uniform distribution of Carbon Black particles within the foam, enabling the conductive properties of the foam. The foam’s mechanical behavior was characterized by a compression test under μCT imaging to measure the deformation behavior and changes in the foam’s resistance. Additionally, a ball drop test was conducted to investigate the foam’s damping behavior while simultaneously measuring the impact location by the local change in resistance. Remarkably, our results demonstrate the exceptional damping capabilities of the conductive silicone foam, with the damping ratio modulated by adjusting the degree of compression-induced deformation. This is attributed to the collapse of the foam’s porous structure, resulting in a significant increase in the foam’s contact area. Overall, our study provides valuable insights into the behavior of conductive silicone foams and their potential as an impact sensing material. The use of both CT and SEM imaging techniques allows for a comprehensive understanding of the foam’s properties, which can be optimized for a variety of applications. The foam’s ability to modulate its damping properties by adjusting the degree of deformation provides a promising avenue for future research in the field of materials science and engineering.
Keywords:
silicone foam; conductive properties; deformation behaviour; damping
Available at various institutes of the ASCR
Conductive open-cell silicone foam for modulatable damping and impact sensing applications
Nature has long served as a source of inspiration for the development of new materials, with foam-like structures in fruits such as oranges and pamelos serving as examples of efficient energy ...
Characterization of five mosaic mortar beds from Austria produced by A. Neuhauser/Tiroler Glasmalerei and J. Pfefferle
Bauerová, Pavla; Frankeová, Dita; Slížková, Zuzana
2023 - English
The report contains the results of material analyses of five mortar beds of mosaics produced by the Austrian studios Neuhauser/Tiroler Glasmalerei and Josef Pfefferle. The analysed samples come from mosaics made at the turn of the 19th and 20th centuries and located in various places in Tyrol. The mortars were analysed by SEM-EDS and thermal analysis. The results showed that, in addition to traditional materials such as marble dust, they also contain atypical or innovative components such as waste ceramic and glass shards or early Portland cement.
Keywords:
SEM-EDS analysis; historic mortar; mosaic; thermal analysis
Available at various institutes of the ASCR
Characterization of five mosaic mortar beds from Austria produced by A. Neuhauser/Tiroler Glasmalerei and J. Pfefferle
The report contains the results of material analyses of five mortar beds of mosaics produced by the Austrian studios Neuhauser/Tiroler Glasmalerei and Josef Pfefferle. The analysed samples come from ...
Vyšetření základních mechanických a lomově-mechanických vlastností vzorků odebraných z VTL plynovodu – lokalita L177/2 po čtrnáctiměsíční expozici ve vlhkém vodíku při tlaku 3 MPa
Gajdoš, Lubomír; Šperl, Martin; Šorm, Filip; Bejdl, Jan
2022 - Czech
Vyšetření vlivu vlhkého vodíku stlačeného na tlak 3 MPa na mechanické a lomové vlastnosti plynovodní oceli ČSN 13126, tahové vzorky, Charpy vzorky i CT vzorky byly během expozice ve vlhkém vodíku trvale zatíženy, po čtrnácti měsících expozice byl zjištěn pokles tažnosti tahových vzorků, pokles lomových parametrů Jin a J0,2 a mírné zvýšení parametru Jm. Investigation of the effect of moist hydrogen pressurized to 3 MPa on mechanical and fracture properties of gas pipeline steel ČSN 13126, tensile specimens, Charpy specimens and CT specimens were kept loaded during the exposition in moist hydrogen, after a fourteen months exposition it was found that ductility of tensile specimens and fracture parameters Jin and J0,2 of CT specimens decreased whilst the parameter Jm was slightly increased.\n
Keywords:
stress-strain diagram; Ramberg-Osgood dependence; impact strength; fracture toughness
Available at various institutes of the ASCR
Vyšetření základních mechanických a lomově-mechanických vlastností vzorků odebraných z VTL plynovodu – lokalita L177/2 po čtrnáctiměsíční expozici ve vlhkém vodíku při tlaku 3 MPa
Vyšetření vlivu vlhkého vodíku stlačeného na tlak 3 MPa na mechanické a lomové vlastnosti plynovodní oceli ČSN 13126, tahové vzorky, Charpy vzorky i CT vzorky byly během expozice ve vlhkém vodíku ...
Příspěvek ke zkoumání nejstarších dějin zámku v Telči
Drdácký, Miloš; Buzek, Jaroslav
2022 - Czech
Souhrnná výzkumná zpráva předkládá výsledky výzkumu nejstarších stavebních reliktů telčského zámku. Využívá radiouhlíkového datování kosterních pozůstatků, nedestruktivního průzkumu termovizí a georadarem a 3D fotogrammetrických rekonstrukcí tvaru a rozměrů architektonických prvků. Analyzuje i templářské stopy na Telčsku a v širším regionu. The summary research report presents the results of research into the oldest building relics of Telč Castle. It uses radiocarbon dating of skeletal remains, non-destructive surveying by thermal imaging and ground-penetrating radar, and 3D photogrammetric reconstructions of the shape and dimensions of architectural elements. It also analyzes Templar traces in Telč region and in the wider region.
Keywords:
historic architecture; Templars; archaeological survey; ground penetrating radar (GPR); age analysis of bones; 3D documentation
Available at various institutes of the ASCR
Příspěvek ke zkoumání nejstarších dějin zámku v Telči
Souhrnná výzkumná zpráva předkládá výsledky výzkumu nejstarších stavebních reliktů telčského zámku. Využívá radiouhlíkového datování kosterních pozůstatků, nedestruktivního průzkumu termovizí a ...
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