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Your search keyword '"Schneider, Konrad"' showing total 16 results
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16 results on '"Schneider, Konrad"'

6. Sprayed Hybrid Cellulose Nanofibril–Silver Nanowire Transparent Electrodes for Organic Electronic Applications

Author

Betker, Marie, primary, Harder, Constantin, additional, Erbes, Elisabeth, additional, Heger, Julian Eliah, additional, Alexakis, Alexandros Efraim, additional, Sochor, Benedikt, additional, Chen, Qing, additional, Schwartzkopf, Matthias, additional, Körstgens, Volker, additional, Müller-Buschbaum, Peter, additional, Schneider, Konrad, additional, Techert, Simone Agnes, additional, Söderberg, L. Daniel, additional, and Roth, Stephan V., additional

Published
2023
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7. Génération de microstructures et analyses multi-échelles à champs complets pour les composites thermoplastiques renforcés de fibres courtes

Author

PRAUD, Francis, SCHNEIDER, Konrad, CHATZIGEORGIOU, George, and MERAGHNI, Fodil

Subjects
Comportement non-linéaire, Génération de microstructures, Modélisation multi-échelle, Thermoplastiques renforcés de fibres courtes, Mécanique: Mécanique des solides [Sciences de l'ingénieur], Mécanique: Mécanique des matériaux [Sciences de l'ingénieur]
Abstract

Les auteurs remercient le Centre HPC Arts et Métiers Cassiopee mis à disposition pour mener les recherches rapportées dans ce travail. Afin d’apporter un maxinmun d’éléments de compréhension quant au comportement mécanique des composites thermoplastiques renforcés de fibres courtes, la présente contribution propose une démarche multi-échelle par champs complets. Pour ce faire, des maillages de VER (Volumes Élémentaires Représentatifs) ont été générés avec un positionnement aléatoire des fibres tandis que leurs orientations sont distribuées selon une ODF (Orientation Distribution Function). Ces VERs présentent une périodicité par construction assurant ainsi une transition d’échelle par homogénéisation périodique. Le comportement à l’échelle macroscopique est ainsi déterminé à partir de simulations par éléments finis de ces VERs, intégrant les lois de comportement spécifiques des constituants et plus particulièrement celui de la matrice thermoplastique décrit ici par un modèle viscoélastique-viscoplastique avec endommagement ductile. L’approche proposée permet ainsi de visualiser les mécanismes locaux de déformation et de dégradation et d’en analyser l’influence sur la réponse macroscopique du composite lors de chargements monotones, persistants et cycliques.

Published
2023

8. Superlattice deformation in quantum dot films on flexible substrates via uniaxial strain

Author

Heger, Julian E., primary, Chen, Wei, additional, Zhong, Huaying, additional, Xiao, Tianxiao, additional, Harder, Constantin, additional, Apfelbeck, Fabian A. C., additional, Weinzierl, Alexander F., additional, Boldt, Regine, additional, Schraa, Lucas, additional, Euchler, Eric, additional, Sambale, Anna K., additional, Schneider, Konrad, additional, Schwartzkopf, Matthias, additional, Roth, Stephan V., additional, and Müller-Buschbaum, P., additional

Published
2023
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12. Beamline-implemented stretching devices for in situ X-ray scattering experiments

Author

Euchler, Eric, Sambale, A. K., Schneider, Konrad, Uhlig, K., Boldt, R., Stommel, M., Stribeck, A., Schwartzkopf, M., Rothkirch, A., and Roth, S. V.

Subjects
History, ddc:530, Computer Science Applications, Education
Abstract

14th International Conference on Synchrotron Radiation Instrumentation, (SRI 2021), Online, 28 Mar 2022 - 1 Apr 2022; Journal of physics / Conference Series 2380(1), 012109 (2022). doi:10.1088/1742-6596/2380/1/012109, Two recently developed experimental devices for investigating soft matterdeformation are presented. Both devices exploit the capabilities of a modern synchrotronbeamline to enable advanced and highly precise materials-science experiments in which X-rayscattering is registered. The devices can be operated both in monotonic as well as cyclic modeand are implemented into a beamline at DESY, Hamburg (Germany). Hence, relevantexperimental parameters, such as displacement, force and temperature, are recordedsynchronously with the individual X-ray scattering patterns. In addition, spatial variation ofmaterials deformation can be monitored and recorded with optical microscopy. This uniquesample environment enables in situ X-ray experiments in transmission, i.e. small- or wide-angleX-ray scattering (SAXS or WAXS), and in grazing-incidence geometry, i.e. grazing-incidence(GI-) SAXS or WAXS. One device with stepper motors is designed for studies of slow, (quasi-)static deformation and the other one with pneumatic actuators can be used for fast, impactdeformation. Both devices are available to external beamline users, too., Published by IOP Publ., Bristol

Published
2022

15. Superlattice deformation in quantum dot films on flexible substrates viauniaxial strainElectronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d2nh00548d

Author

Heger, Julian E., Chen, Wei, Zhong, Huaying, Xiao, Tianxiao, Harder, Constantin, Apfelbeck, Fabian A. C., Weinzierl, Alexander F., Boldt, Regine, Schraa, Lucas, Euchler, Eric, Sambale, Anna K., Schneider, Konrad, Schwartzkopf, Matthias, Roth, Stephan V., and Müller-Buschbaum, P.

Abstract

The superlattice in a quantum dot (QD) film on a flexible substrate deformed by uniaxial strain shows a phase transition in unit cell symmetry. With increasing uniaxial strain, the QD superlattice unit cell changes from tetragonal to cubic to tetragonal phase as measured with in situgrazing-incidence small-angle X-ray scattering (GISAXS). The respective changes in the optoelectronic coupling are probed with photoluminescence (PL) measurements. The PL emission intensity follows the phase transition due to the resulting changing inter-dot distances. The changes in PL intensity accompany a redshift in the emission spectrum, which agrees with the Förster resonance energy transfer (FRET) theory. The results are essential for a fundamental understanding of the impact of strain on the performance of flexible devices based on QD films, such as wearable electronics and next-generation solar cells on flexible substrates.

Published
2023
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16. First‐Time Investigations on Cavitation in Rubber Parts Subjected to Constrained Tension Using In Situ Synchrotron X‐Ray Microtomography (SRμCT).

Author

Euchler, Eric, Bernhardt, Ricardo, Wilde, Fabian, Schneider, Konrad, Heinrich, Gert, Tada, Toshio, Wießner, Sven, and Stommel, Markus

Subjects
X-ray computed microtomography, CAVITATION, RUBBER, STYRENE-butadiene rubber, CAVITATION erosion, HYDROSTATIC stress, SYNCHROTRONS, X-ray imaging
Abstract

Cavitation under constrained tension is a critical failure phenomenon in rubber parts. For laboratory tests, strain constraints can be generated using disk‐shaped rubber samples, that is, pancake specimens. Due to suppressed transverse contractibility, the dominating hydrostatic tensile stress, which is the highest in the center part of a pancake specimen, causes an internal failure process controlled by the formation and growth of cavities. Laboratory X‐ray microtomography (μCT) is a powerful tool to monitor the evolution of a cavity population considering various aspects of geometrical as well as microstructural constraints. In the case of carbon black–reinforced styrene‐butadiene rubber, microscopic cavities are surrounded by a region of significantly lower material density. Due to detection limits, this region cannot be analyzed in depth with μCT. In this study, synchrotron X‐ray microtomography (SRμCT) in combination with a modular load frame is used, for the first time, to investigate the damaging phenomenon of cavitation in rubbers. Due to the high phase contrast that can be achieved only by SRμCT, the microstructure of regions of lower material density can be analyzed and, as a result, tiny satellite cavities are identified in the walls of neighboring microscopic cavities. [ABSTRACT FROM AUTHOR]

Published
2021
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