Posting on the information boards:
Institute for Leightweight Structures and Conceptual Design, ILEK
Pfaffenwaldring 7, 2nd floor
BACHELOR | MASTER
In this BSc. or MSc. project, the candidate will join a small and interdisciplinary team of architects, cybernetic/control
and mechanical engineers working on an adaptive kinetic façade project funded by the DFG, German Research
Foundation. As a Bachelor/Master student you will support A07 research project part of the CRC1244, where
the task is to research, design and develop transformable joints and soft actuators.
Jun. Prof. Dr.-Ing. Maria Matheou, Institute for Lightweight Structures and Conceptual Design (ILEK)
Dr.-Ing. Michael Böhm, Institute for System Dynamics (ISYS)
• Literature research on state-of-the-art transformable joints and soft actuators
• Design and development of a transformable joint
• Implement simple automation concept
• 3D modelling and Prototyping
We are looking forward to your application with resume, portfolio and transcript of records under the keyword
"SFB 1244 - A07_Thesis“.
Jun. Prof. Dr.-Ing. Maria Matheou
T +49 (0)711 685 61698
The bridge stock in the Trans-European Transport Network (TEN-T) is aging and it has been estimated that approximately 40-50% of the bridges in Germany, Netherlands and Denmark and Portugal will soon approach the end of service (older than 40 years). In addition, given the increased traffic demand, most bridges built before 1980 typically experience significantly stronger solicitations than the loads they were designed to withstand.
External post-tensioning can be used effectively to improve the serviceability performance of a bridge and to delay or prevent the onset of damage (e.g., cracking) . Since typical post-tensioning increases flexural stiffness, it has been successfully employed to reduce in-service deflections and vibrations of short-span bridges . Post-tensioning has been primarily implemented using unbonded tendons that run through the bridge cross-section and are anchored at the bridge ends. The tendons can be straight or draped using deviators. In either case, the tension force from the external cables is applied eccentrically to the neutral axis of the bridge cross-section. The resulting system of forces induces a bending moment that counteracts the effect of the external load. However, conventional external post-tensioning systems can only be effective against one loading condition, which is usually the permanent load. In scenarios where the live load is commensurate with the dead load and strict criteria for safety and serviceability apply, e.g., for high-speed railway bridges, conventional post-tensioning does not perform optimally.
Previous work has shown that structural adaptation can be employed to significantly improve structural capacity through stress homogenization by redirecting the force flow from critically stressed elements to lower-stressed elements –. In addition, adaptation can be employed to improve serviceability performance by reducing deflections and vibrations, . Most bridges typically retain a significant reserve capacity  that could be unlocked through optimal retrofitting of control systems (e.g., sensors, actuators, and processing units) thus avoiding costly decommission and replacement by extending their service life.
External adaptive tensioning (EAT) systems can be retrofitted to existing bridges and employed for the design of new bridges . A type of external adaptive post-tensioning system that is well-suited for retrofitting on different bridge types comprises cables deviated by variable-length compressive struts that are fixed below the bridge deck, as shown in Figure 1. Linear actuators adjust the length of the structs, which changes the tension in the cables allowing manipulation of the bending moment as the load changes. Simulations have been carried out on high-speed railway bridges modeled with simply supported steel-composite beams. Active control performed by the EAT system enables satisfying required vertical acceleration limits without the need to increase flexural stiffness by adding more material .
This work will investigate several bridge configurations and evaluate the potential of active control through different actuation strategies including EAT. This research project comprises two main tasks:
- Evaluation of the adaptation potential of beam, frame, truss, arch, suspension and cable-stayed bridges. This task involves modeling and simulation to evaluate how the structural capacity and serviceability performance can be improved through different actuation systems.
- Development of actuation strategies to extend the service life of existing and new bridges by mitigating the effect of heavy crossing to reduce the cyclic stress range.
For short- to medium-span highway and railway bridges, the objective is to reduce vibrations and stresses caused by heavy loading to extend the service life by mitigating fatigue effects. The potential of adaptation on the performance of lightweight (e.g., pedestrian), as well as stiffness-dominated bridges including long-span cable-stay and suspension configurations, will also be considered. For new bridges, the objective is to improve the structural performance by reducing significantly material mass requirements and in parallel increasing the span.
Dr. Eng. habil. Gennaro Senatore, firstname.lastname@example.org
Institute for Lightweight Structures and Conceptual Design (ILEK)
Supervision will be carried out in English.
Dr.Eng. habil. Gennaro Senatore (email@example.com)
Dr. ès sc. Arka P. Reksowardojo (firstname.lastname@example.org)
The clear link between climate change and the environmental impact of the construction industry calls for innovative design approaches as well as alternative material solutions. Novel design strategies are emerging through the integration of advanced material research, computational design, and fabrication techniques. This higher level of integration allows materials that were previously considered as structurally insufficient, such as biomaterials, to be used in the context of built environment. By employing computer-aided shape optimization and form-finding, geometries that are most appropriate for given material properties can be obtained. In addition, 3D printing enables fabrication of complex geometries that are otherwise infeasible through conventional means.
Currently, large-scale 3D printing of Natural Fibre-Reinforced Polymers (NFRPs) has not yet been fully explored, especially in the use of continuous fibre filaments. From load-bearing point of view, the integration of continuous fibre within structural elements can be advantageous since it allows a contiguous distribution of forces. Conventional techniques for manufacturing continuous Fibre-reinforced polymers (FRPs) include several complex processes and steps, resulting in intense labour and energy expenditure. On the other hand, 3D printing of fibre filaments can produce complex geometries through the combination of fibre impregnation, deposition, and curing within a one-step process that can accommodate single or multi-material deposition.
In this project, a proof-of-concept prototype of 3D printed beam will be synthesized through topology optimization and then fabricated. To this end, the candidate will be expected to complete the following work packages: (1) literature review on biomaterials and 3D printed structures; (2) material characterization of 3D printed NFRP from existing empirical data and testing of new specimens; (3) topology optimization and modelling of the beam prototype (4) fabrication of 3D printed beam.
Note that thesis supervision, writing, and examination will be carried out in English.
• Bachelor’s degree in civil engineering or architecture.
• Good knowledge of form-finding and finite element (FE) modelling.
• Notional knowledge or interest in structural optimization.
• Fluency in FE software (Abaqus/SOFiSTiK) and programming (Python/MATLAB).
• Experience and interest in 3D printing and/or biomaterials are an advantage.
• Proficiency in spoken and written English.
Earliest starting date:
In Deutschland entfallen mehr als 30% des Primärenergiebedarfs auf die Klimatisierung von Gebäuden . Der überwiegende Teil dieser Primärenergie stammt nach wie vor aus fossilen Energieträgern (siehe Abb. 1). Daher müssen radikal neue Ansätze entwickelt werden, um die Emissionen zu reduzieren und den Klimawandel zu bremsen. Der Einsatz von Künstlicher Intelligenz in Kombination mit adaptiven Fassaden bietet eine wesentliche Lösung, um den Energiebedarf für die Gebäudekonditionierung und die damit verbundenen Emissionen signifikant
zu reduzieren und gleichzeitig den Nutzerkomfort zu erhöhen. Um die Weichen für eine nachhaltigere Zukunft zu stellen, ist es notwendig, fundierte Grundlagen zu schaffen und Lösungsansätze aufzuzeigen. Dazu werden Sie sich in Ihrer Abschlussarbeit mit relevanten Fragestellungen rund um die Steuerung von adaptiven Fassaden mittels der Methoden des maschinellen Lernens auseinandersetzen.
• Wie sollte ein Modell aufgebaut sein, um eine Generalisierung auf unterschiedliche Gebäude, adaptive Fassaden und Umgebungen unter realen Bedingungen zu ermöglichen?
• Welche Daten werden für effizient lernende Algorithmen benötigt?
• Wie kann das Nutzerverhalten als Interaktion mit der Künstlichen Intelligenz in den Lernprozess integriert werden und welche Eigenschaften müssen die adaptiven Fassaden haben?
• Wie müssen Bewertungskriterien formuliert werden, um das Lernverhalten von Algorithmen zuverlässig zu steuern und welche Arten von adaptiven Fassaden müssen berücksichtigt werden?
Die Arbeit erfordert eine umfassende Literaturrecherche sowie die Anwendung von Methoden und Werkzeugen des maschinellen Lernens. Die Ergebnisse Ihrer Arbeit werden dazu beitragen den Energiebedarf von Gebäuden zu reduzieren und den Nutzerkomfort erhöhen.
Bewerben Sie sich noch heute und gestalten Sie mit uns die Zukunft!
Silas Kalmbach, M.Sc.
+49 (0)711 685 63820