34 research outputs found

    Ein Beitrag zur Berechnung und Optimierung von Hubschrauber-Startverfahren

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    Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

    Residual force and deformation measurement in FDM 4D printing

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    In FDM 4D printing, residual stresses are purposely introduce into a structure by controlling the print parameters. The residual stress introduction can be interpreted as the programming step of the shape memory cycle. However, for shape memory polymers the commonly recorded quantities are stress, strain and temperature. Therefore, we increase the knowledge about the programming step by measuring the programming force during printing and the recovered deformation after printing. These two values translate to programming stress and recovered strain, when considering the geometry of the printed line and the specimen, respectively. The programming force is measured in x-direction with four load cells based on strain gauges, which are mounted below the print platform. The force is transfered by the material from the nozzle movement onto the print platform. This force is interpreted as the programming force, which translates to programming stress by considering the cross-section of a printed line. The recovered deformation is quantified by the curvature of a bending section. Active bottom layers contain high residual stress, while the passive top layers contain low or near-zero residual stress. The deformation is activated by immersing the specimens in hot water. This leads to the recovery of the residual strain, which causes the specimen to bend. The curvature is interpreted as a strain difference between the active and passive layers, by considering the specimens height. The parameter study was carried out for nozzle temperature, print speed, and melt zone length to investigate their influence on the relationship between programming stress and recovered strain. The results show that the relationship between programming stress and recovered strain depends on the printing parameters, meaning, that on programming force can lead to different recovered strains. This depends on the varied parameter in our study

    Electric Vehicles in Shared Fleets: Mobility Management, Business Models, and Decision Support Systems

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    The electrification of shared fleets offers numerous benefits, including the reduction of local emissions of pollutants, which leads to ecological improvements such as the improvement of air quality. Electric Vehicles in Shared Fleets considers a holistic concept for a socio-technical system with a focus on three core areas: integrated mobility solutions, business models for economic viability, and information systems that support decision-making for the successful implementation and operation of electric vehicles in shared fleets.In this book, we examine different aspects within these areas including multimodal mobility, grid integration of electric vehicles, shared autonomous electric vehicle services, relocation strategies in shared fleets, and the challenge of battery life of electric vehicles. Insights into the future of transport are provided, which is predicted to be shared, autonomous, and electric. This will require the expansion of the charging infrastructure to provide adequate premises for the electrification of transportation and to create market demand

    Prozessnahe Einsatzoptimierung mit BoFiT unter Beruecksichtigung der Netzrestriktionen Schlussbericht

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    The aim of the project is to integrate the new software system BoFiT, developed in the compound project, in the daily operation of HEW. Three subtasks have been successfully completed. First, BoFiT was adapted to the requirements of a large heterogeneous works' park, and today it calculates the decisions on the use of the various plants during the daily operation. Secondly, BoFiT was connected to the management system, so that an optimised operational point can be calculated based on real operating data. Thirdly, a link to electricity trading was made in which data on free capacities and the corresponding costs are made available for a software tool for the trade.(orig.)Das Projekt hatte zum Ziel, das neue Softwaresystem BoFiT, das im Rahmen des Verbundprojekts entwickelt worden war, in den Tagesbetrieb der HEW zu integrieren. Drei Teilaufgaben wurden erfolgreich abgeschlossen: Erstens wurde BoFiT an die Erfordernisse eines grossen heterogenen Anlagenparks angepasst, und es berechnet heute die Einsatzentscheidungen der Anlagen im Tagesbetrieb. Zweitens wurde BoFiT mit der Leittechnik gekoppelt, so dass nach Bedarf und auf der Basis echter Betriebsdaten ein optimaler Betriebspunkt berechnet werden kann. Drittens wurde eine Anbindung an den Stromhandel realisiert, indem die Daten der freien Leistung und ihrer Kosten fuer ein Softwaretool des Handels zur Verfuegung gestellt werden. (orig.)SIGLEAvailable from TIB Hannover: F02B1512 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman
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