Reliability of adaptive structures
The reliability of a structure is a measure for its safety. In adaptive structures, there‘s more components to be considered for the assessment of reliability than just the passive parts. In these structures, actuators, sensors, and the control play important roles - which result in additional risks, other failure modes, and new dependencies. All of these have to be identified and analyzed, and they have to be considered in the reliability assessment. To obtain sustainability in construction, it is of high significance that adaptive structures are being designed in a reliability- and safety-oriented way. The better the operational load-cases are known beforehand, the better the design of the structure can meet the requirements of reliability.
The partial or complete failure of the actuator, sensor, or control system plays a decisive role for reliability in the context of adaptive structures in civil engineering. From this, the central questions of this subproject are derived. This involves the analysis of redundancies in structural topologies, the detection of failure cases, as well as the lifetime monitoring for the compliance with the ultimate limit state and the serviceability. In order to ensure structural safety in the event of the failure of actuators, sensors and control systems, it is investigated how current standards in civil engineering are applicable to adaptive structures or how they have to be extended.
Analysis of redundancies
Furthermore, the aim of this subproject is to investigate how redundancies in the structural topology can be utilized for reliability analysis. In order to ensure structural safety and serviceability in case of failure in the adaptive components, it will be investigated to what extent the analysis of redundancies in the system can be applied to the evaluation of failure cases, as well as to the design of the structure. The challenge hereby lies in deducing the influence of the topology of the structure and the location of the actuators on reliability. In addition, it will be explored how adaptive structures have to be designed to withstand actuator failure and if they can be moved into a safe state by means of stored passive energy or intentional additional dissipation.
The detection and isolation of failure modes in actuators, sensors, and structure are fundamental to ensure safety and serviceability by appropriate measures. It has been shown that the number and placement of sensors has a significant impact on the detectability and differentiability of failure cases. Therefore, quality measures and methods for actuator and sensor placement are being developed to ensure a high failure tolerance, as well as a good detectability and differentiability of failure cases for the subsequent failure diagnosis.
Teilprojekt B03 - Methoden und Technologien für ausfallsichere adaptive Tragwerke
German Research Foundation (DFG), Collaborative Research Centre SFB 1244 "Adaptive Hüllen und Strukturen für die gebaute Umwelt von morgen", GEPRIS project number 324667137
Institute of Machine Components (IMA), University of Stuttgart
Institute for System Dynamics (ISYS), University of Stuttgart
- Geiger, F., Gade, J., von Scheven, M., & Bischoff, M. (2020). Optimal Design of Adaptive Structures vs. Optimal Adaption of Structural Design. IFAC-PapersOnLine, 53(2), 8363--8369. https://doi.org/10.1016/j.ifacol.2020.12.1604
- Geiger, F., Gade, J., von Scheven, M., & Bischoff, M. (2020). Anwendung der Redundanzmatrix bei der Bewertung adaptiver Strukturen. Manfred Bischoff, Malte von Scheven, Bastian Oesterle (Hrsg.) Berichte der Fachtagung Baustatik – Baupraxis 14, 23. und 24. März 2020, Universität Stuttgart, 119–128. https://doi.org/10.18419/opus-10762
- Wagner, J. L., Gade, J., Heidingsfeld, M., Geiger, F., von Scheven, M., Böhm, M., Bischoff, M., & Sawodny, O. (2018). On steady-state disturbance compensability for actuator placement in adaptive structures. at – Automatisierungstechnik, 66, 591–603. https://doi.org/10.1515/auto-2017-0099