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Werner Sobek - One of the best experts on this subject based on the ideXlab platform.

  • Second-Generation Implants for Load Introduction into Thin-Walled CFRP-Reinforced UHPC Beams: Implant Optimisation and Investigations of Production Technologies
    Materials (Basel Switzerland), 2019
    Co-Authors: Benjamin Kromoser, Oliver Gericke, Mathias Hammerl, Werner Sobek
    Abstract:

    Combining two high-performance Materials—ultra-high-performance concrete (UHPC) as the matrix and carbon-fibre-reinforced composites (CFRP) as the reinforcement—opens up new possibilities for achieving very lightweight thin-walled concrete elements. This strategy, however, leads to a higher degree of Material Utilisation, resulting in the generation of higher forces around load introduction points and supports. The authors present a solution for increasing the performance of supports of very slender CFRP-reinforced UHPC beams by using metal implants. Implants are used in place of concrete in regions of stress concentrations and significant deviation forces. These are able to transfer high stresses and forces efficiently due to their ability to sustain both tension and compression in equal measure. A key issue in their development is the interface between the reinforced concrete and metal implant. Building on previous research, this paper deals with the conceptual design of three types of implants manufactured from different metals and with three different types of automated production technologies (water-jet cutting, metal casting with a 3D-printed plastic formwork and binder jetting of steel components). For this paper, tests were carried out to determine the load-bearing behaviour of beams with the three different types of support implants used for load introduction at the supports. A carbon rod served as bending reinforcement and a pre-formed textile reinforcement cage served as shear and constructive reinforcement.

  • Implants for load introduction into thin-walled CFRP-reinforced UHPC beams
    Composite Structures, 2018
    Co-Authors: Benjamin Kromoser, Oliver Gericke, Werner Sobek
    Abstract:

    Abstract Combining two high-performance Materials – viz. ultra-high performance concrete (UHPC) as the matrix, and carbon fibre reinforced polymers (CFRP) as the reinforcement – opens up new possibilities of achieving concrete elements with thin walls and minmial weight. This strategy, however, results in a higher degree of Material Utilisation, which impedes load transfer from such thin-walled concrete elements to auxiliary constructions such as superordinate load-bearing systems. The authors present a solution for the load transfer from very slender CFRP-reinforced UHPC beams to its supports via steel implants (Sobek and Mittelstadt, 2012; Kobler, 2013; Mittelstadt, 2015). In this paper, the conceptual design of three different types of implants is presented. The geometry of the implant and especially the connection of the CFRP reinforcement to the steel implant are examined in detail. For this paper the authors tested beams with three different types of implants and three different configurations of the textile CFRP reinforcement serving as structural and shear reinforcement.

Benjamin Kromoser - One of the best experts on this subject based on the ideXlab platform.

  • Second-Generation Implants for Load Introduction into Thin-Walled CFRP-Reinforced UHPC Beams: Implant Optimisation and Investigations of Production Technologies
    Materials (Basel Switzerland), 2019
    Co-Authors: Benjamin Kromoser, Oliver Gericke, Mathias Hammerl, Werner Sobek
    Abstract:

    Combining two high-performance Materials—ultra-high-performance concrete (UHPC) as the matrix and carbon-fibre-reinforced composites (CFRP) as the reinforcement—opens up new possibilities for achieving very lightweight thin-walled concrete elements. This strategy, however, leads to a higher degree of Material Utilisation, resulting in the generation of higher forces around load introduction points and supports. The authors present a solution for increasing the performance of supports of very slender CFRP-reinforced UHPC beams by using metal implants. Implants are used in place of concrete in regions of stress concentrations and significant deviation forces. These are able to transfer high stresses and forces efficiently due to their ability to sustain both tension and compression in equal measure. A key issue in their development is the interface between the reinforced concrete and metal implant. Building on previous research, this paper deals with the conceptual design of three types of implants manufactured from different metals and with three different types of automated production technologies (water-jet cutting, metal casting with a 3D-printed plastic formwork and binder jetting of steel components). For this paper, tests were carried out to determine the load-bearing behaviour of beams with the three different types of support implants used for load introduction at the supports. A carbon rod served as bending reinforcement and a pre-formed textile reinforcement cage served as shear and constructive reinforcement.

  • Implants for load introduction into thin-walled CFRP-reinforced UHPC beams
    Composite Structures, 2018
    Co-Authors: Benjamin Kromoser, Oliver Gericke, Werner Sobek
    Abstract:

    Abstract Combining two high-performance Materials – viz. ultra-high performance concrete (UHPC) as the matrix, and carbon fibre reinforced polymers (CFRP) as the reinforcement – opens up new possibilities of achieving concrete elements with thin walls and minmial weight. This strategy, however, results in a higher degree of Material Utilisation, which impedes load transfer from such thin-walled concrete elements to auxiliary constructions such as superordinate load-bearing systems. The authors present a solution for the load transfer from very slender CFRP-reinforced UHPC beams to its supports via steel implants (Sobek and Mittelstadt, 2012; Kobler, 2013; Mittelstadt, 2015). In this paper, the conceptual design of three different types of implants is presented. The geometry of the implant and especially the connection of the CFRP reinforcement to the steel implant are examined in detail. For this paper the authors tested beams with three different types of implants and three different configurations of the textile CFRP reinforcement serving as structural and shear reinforcement.

Oliver Gericke - One of the best experts on this subject based on the ideXlab platform.

  • Second-Generation Implants for Load Introduction into Thin-Walled CFRP-Reinforced UHPC Beams: Implant Optimisation and Investigations of Production Technologies
    Materials (Basel Switzerland), 2019
    Co-Authors: Benjamin Kromoser, Oliver Gericke, Mathias Hammerl, Werner Sobek
    Abstract:

    Combining two high-performance Materials—ultra-high-performance concrete (UHPC) as the matrix and carbon-fibre-reinforced composites (CFRP) as the reinforcement—opens up new possibilities for achieving very lightweight thin-walled concrete elements. This strategy, however, leads to a higher degree of Material Utilisation, resulting in the generation of higher forces around load introduction points and supports. The authors present a solution for increasing the performance of supports of very slender CFRP-reinforced UHPC beams by using metal implants. Implants are used in place of concrete in regions of stress concentrations and significant deviation forces. These are able to transfer high stresses and forces efficiently due to their ability to sustain both tension and compression in equal measure. A key issue in their development is the interface between the reinforced concrete and metal implant. Building on previous research, this paper deals with the conceptual design of three types of implants manufactured from different metals and with three different types of automated production technologies (water-jet cutting, metal casting with a 3D-printed plastic formwork and binder jetting of steel components). For this paper, tests were carried out to determine the load-bearing behaviour of beams with the three different types of support implants used for load introduction at the supports. A carbon rod served as bending reinforcement and a pre-formed textile reinforcement cage served as shear and constructive reinforcement.

  • Implants for load introduction into thin-walled CFRP-reinforced UHPC beams
    Composite Structures, 2018
    Co-Authors: Benjamin Kromoser, Oliver Gericke, Werner Sobek
    Abstract:

    Abstract Combining two high-performance Materials – viz. ultra-high performance concrete (UHPC) as the matrix, and carbon fibre reinforced polymers (CFRP) as the reinforcement – opens up new possibilities of achieving concrete elements with thin walls and minmial weight. This strategy, however, results in a higher degree of Material Utilisation, which impedes load transfer from such thin-walled concrete elements to auxiliary constructions such as superordinate load-bearing systems. The authors present a solution for the load transfer from very slender CFRP-reinforced UHPC beams to its supports via steel implants (Sobek and Mittelstadt, 2012; Kobler, 2013; Mittelstadt, 2015). In this paper, the conceptual design of three different types of implants is presented. The geometry of the implant and especially the connection of the CFRP reinforcement to the steel implant are examined in detail. For this paper the authors tested beams with three different types of implants and three different configurations of the textile CFRP reinforcement serving as structural and shear reinforcement.

Vimal Dhokia - One of the best experts on this subject based on the ideXlab platform.

  • Hybrid additive and subtractive machine tools – Research and industrial developments
    International Journal of Machine Tools & Manufacture, 2016
    Co-Authors: Joseph Flynn, Alborz Shokrani, Stephen T. Newman, Vimal Dhokia
    Abstract:

    Abstract By synergistically combining additive and subtractive processes within a single workstation, the relative merits of each process may be harnessed. This facilitates the manufacture of internal, overhanging and high aspect ratio features with desirable geometric accuracy and surface characteristics. The ability to work, measure and then rework Material enables the reincarnation and repair of damaged, high-value components. These techniques present significant opportunities to improve Material Utilisation, part complexity and quality management in functional parts. The number of single platform workstations for hybrid additive and subtractive processes (WHASPs) is increasing. Many of these integrate additive directed energy deposition (DED) with subtractive CNC machining within a highly mobile multi-axis machine tool. Advanced numerical control (NC), and computer aided design (CAD), manufacture (CAM) and inspection (CAI) help to govern the process. This research reviews and critically discusses salient published literature relating to the development of WHASPs, and identifies future avenues for research and development. It reports on state-of-the-art WHASP systems, identifying key traits and research gaps. Finally, a future vision for WHASPs and other hybrid machine tools is presented based upon emerging trends and future opportunities within this research area.

  • hybrid additive and subtractive machine tools research and industrial developments
    International Journal of Machine Tools & Manufacture, 2016
    Co-Authors: Joseph Flynn, Alborz Shokrani, Stephen T. Newman, Vimal Dhokia
    Abstract:

    Abstract By synergistically combining additive and subtractive processes within a single workstation, the relative merits of each process may be harnessed. This facilitates the manufacture of internal, overhanging and high aspect ratio features with desirable geometric accuracy and surface characteristics. The ability to work, measure and then rework Material enables the reincarnation and repair of damaged, high-value components. These techniques present significant opportunities to improve Material Utilisation, part complexity and quality management in functional parts. The number of single platform workstations for hybrid additive and subtractive processes (WHASPs) is increasing. Many of these integrate additive directed energy deposition (DED) with subtractive CNC machining within a highly mobile multi-axis machine tool. Advanced numerical control (NC), and computer aided design (CAD), manufacture (CAM) and inspection (CAI) help to govern the process. This research reviews and critically discusses salient published literature relating to the development of WHASPs, and identifies future avenues for research and development. It reports on state-of-the-art WHASP systems, identifying key traits and research gaps. Finally, a future vision for WHASPs and other hybrid machine tools is presented based upon emerging trends and future opportunities within this research area.

Troy W. Farrell - One of the best experts on this subject based on the ideXlab platform.

  • Predicting active Material Utilisation in LiFePO4 electrodes using a multi-scale mathematical model
    Journal of The Electrochemical Society, 2010
    Co-Authors: Steven Dargaville, Troy W. Farrell
    Abstract:

    A mathematical model is developed to simulate the discharge of a LiFePO4 cathode. This model contains 3 size scales, which match with experimental observations present in the literature on the multi-scale nature of LiFePO4 Material. A shrinking-core is used on the smallest scale to represent the phase-transition of LiFePO4 during discharge. The model is then validated against existing experimental data and this validated model is then used to investigate parameters that influence active Material Utilisation. Specifically the size and composition of agglomerates of LiFePO4 crystals is discussed, and we investigate and quantify the relative effects that the ionic and electronic conductivities within the oxide have on oxide Utilisation. We find that agglomerates of crystals can be tolerated under low discharge rates. The role of the electrolyte in limiting (cathodic) discharge is also discussed, and we show that electrolyte transport does limit performance at high discharge rates, confirming the conclusions of recent literature.