Dr.-Ing.

Albrecht, Stefan

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  • Publication
    Sustainable Pultruded Sandwich Profiles with Mycelium Core
    ( 2023-07-28)
    Früchtl, Marion
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    Senz, Andreas
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    Sydow, Steffen
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    Frank, Jonas Benjamin
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    Hohmann, Andrea
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    Albrecht, Stefan orcid-logo
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    Fischer, Matthias orcid-logo
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    Holland, Maximilian
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    Wilhelm, Frederik
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    Christ, Henrik-Alexander
    This research focuses on exploring the potential of mycelium as a sustainable alternative to wood or solid foam in pultruded glass fiber-reinforced plastic (GFRP) sandwich profiles. The study evaluates the performance and the environmental sustainability potential of this composite by mechanical tests and life cycle assessment (LCA). Analysis and comparison of pultruded sandwich profiles with mycelium, polyurethane (PUR) foam and chipboard demonstrate that mycelium is competitive in terms of its performance and environmental impact. The LCA indicates that 88% of greenhouse gas emissions are attributed to mycelium production, with the heat pressing (laboratory scale) being the main culprit. When pultruded profiles with mycelium cores of densities 350 and 550 kg/m 3 are produced using an oil-heated lab press, a global warming potential (GWP) of 5.74 and 9.10 kg CO 2-eq. per functional unit was calculated, respectively. When using an electrically heated press, the GWP decreases to 1.50 and 1.78 kg CO 2-eq. Compared to PUR foam, a reduction of 23% in GWP is possible. In order to leverage this potential, the material performance and the reproducibility of the properties must be further increased. Additionally, an adjustment of the manufacturing process with in situ mycelium deactivation during pultrusion could further reduce the energy consumption.
  • Publication
    Reliability as a Key Driver for a Sustainable Design of Adaptive Load-Bearing Structures
    ( 2022-01-13)
    Efinger, Dshamil
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    Ostertag, Andreas
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    Dazer, Martin
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    Borschewski, David Sven
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    Albrecht, Stefan orcid-logo
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    Bertsche, Bernd
    The consumption of construction materials and the pollution caused by their production can be reduced by the use of reliable adaptive load-bearing structures. Adaptive load-bearing structures are able to adapt to different load cases by specifically manipulating internal stresses using actuators installed in the structure. One main aspect of quality is reliability. A verification of reliability, and thus the safety of conventional structures, was a design issue. When it comes to adaptive load-bearing structures, the material savings reduce the stiffness of the structure, whereby integrated actuators with sensors and a control take over the stiffening. This article explains why the conventional design process is not sufficient for adaptive load-bearing structures and proposes a method for demonstrating improved reliability and environmental sustainability. For this purpose, an exemplary adaptive load-bearing structure is introduced. A linear elastic model, simulating tension in the elements of the adaptive load-bearing structure, supports the analysis. By means of a representative local load-spectrum, the operating life is estimated based on Woehler curves given by the Eurocode for the critical notches. Environmental sustainability is increased by including reliability and sustainability in design. For an exemplary high-rise adaptive load-bearing structure, this increase is more than 50%.