Characterisation and modelling of adaptive structures

Research project

(Project B01 of the Collaborative research center SFB 1244)

Overview

  • Background
  • Characterization of adaptive structures
  • Modelling of the actuation

Project description

Background

Since the early 1970s, structures that can react automatically to a change in external loads or boundary conditions have been investigated in the USA. Mainly the aerospace industry was interested in these developments, as they lead to economic lightweight structures. In the last few years, sustainability and economical lightweight structures have played a major role in construction, which is why adaptive systems are becoming the focus of research. There are various application fields where adaptive systems offer efficient solutions. Mainly the aims are to influence design-decisive peak loads, to homogenize stress states and to reduce deformations.

Adaptivity of structures describes the ability to react automatically to a change in external loads or boundary conditions. This reaction can be carried out in various ways, e.g. changes of geometry, forces or material properties, which can be made by actuators. The control of the actuators requires a sensor system, which is able to detect the effects of the changes on the load-bearing structure. Thereupon a controlled reaction of the actuator system can be executed in order to configure the load-bearing structure optimally for the prevailing situation.

Stuttgarter Träger Adaptivity
Simulation of the "Stuttgarter Träger" (ILEK): Reduction of the vertical deformation under the single load by horizontal actuation of the right support. Passive state above, active state below.

Characterization of adaptive structures

Crucial for the work with adaptive systems is the definition of what an adaptive system exactly is. The required terminology, which is quite different in the fields of mechanical-, control- and civil-engineering, has to be brought together. In order to compare different designs, objective measures to value an adaptive system are needed. They can be calculated using redundancy contributions, gramian controllability matrices or similar. These matrices contain information, which can be used for an optimized placement of actuators in the structure. This is a crucial point in the assessment of the performance of an adaptive structure. Using a suitable actuator placement and control, e.g. stiffness-governed design tasks can be transferred into strength-governed tasks. For example, in the design of high-rise or wide spanned structures, the design decisive results can be deformations or accelerations in the structure. A well-designed adaptive structure is able to manipulate those quantities in order to reduce the amount of matter significantly, which is needed in the primary structure to comply with constraints.

Sizing passive vs active
Comparison of results for a sizing of the cross sections of a passive (left) and an adaptive Structure (right) subjected to the same load cases and constraints. The maximum utilizations of the cross sections (a) are larger in the adaptive structure, therefore smaller cross sections (b) are necessary, what leads to a lighter structure.

Modelling of the actuation

The focus in this research area is the modelling and simulation of adaptive systems. To carry out an exact analysis, which represents the behaviour of the adaptive structure realistically, the actuators, sensors and control technology must be integrated into the model. This is also beneficial in the development of algorithms that control the system. Towards an efficient simulation of adaptive structures using the finite element method, suitable finite actuator elements are defined.

Active truss element
Retracting active truss element.

Project data

Project title:
Teilprojekt B01 - Charakterisierung, Modellierung und Reduktion adaptiver Tragwerke
project webpage
Funding:

German Research Foundation (DFG), Collaborative Research Centre SFB 1244 "Adaptive Hüllen und Strukturen für die gebaute Umwelt von morgen", GEPRIS project number 324663295
Project partner:
Institute of Engineering and Computational Mechanics (ITM), University of Stuttgart

Researchers:
Tamara Prokosch, Lisa-Marie Krauß

Publications

  1. Krauß, L.-M., Maierhofer, M., Prokosch, T., Trautwein, A., von Scheven, M., Menges, A., & Bischoff, M. (2024). Baustatische Methoden für Entwurf, Auslegung und Betrieb adaptiver Tragwerke. In B. Oesterle, A. Bögle, W. Weber, & L. Striefler (Eds.), Berichte der Fachtagung Baustatik – Baupraxis 15, 04. und 05. März 2024, Hamburg (pp. 101--108). https://doi.org/10.15480/882.9247
  2. Krauß, L.-M., von Scheven, M., & Bischoff, M. (2023). Combining the redundancy concept and vibration control for actuator placement in adaptive structures. X ECCOMAS Thematic Conference on Smart Structures and Materials, SMART 2023, Patras, Greece. https://doi.org/10.7712/150123.9826.444394
  3. Trautwein, A., Prokosch, T., Senatore, G., Blandini, L., & Bischoff, M. (2023). Analytical and numerical case studies on tailoring stiffness for the design of structures with displacement control. Frontiers in Built Environment, 9. https://doi.org/10.3389/fbuil.2023.1135117
  4. Geiger, F. (2022). Strukturmechanische Charakterisierung von Stabtragwerken für den Entwurf adaptiver Tragwerke. Doktorarbeit, Bericht Nr. 74. Institut für Baustatik und Baudynamik der Universität Stuttgart. https://doi.org/10.18419/opus-12299
  5. Krake, T., von Scheven, M., Gade, J., Abdelaal, M., Weiskopf, D., & Bischoff, M. (2022). Efficient Update of Redundancy Matrices for Truss and Frame Structures. Journal of Theoretical, Computational and Applied Mechanics. https://doi.org/10.46298/jtcam.9615
  6. Böhm, M., Steffen, S., Gade, J., Geiger, F., Sobek, W., Bischoff, M., & Sawodny, O. (2020). Modellierung aktiver Strukturelemente als Erweiterung zum klassischen Workflow der FE-Analyse. Manfred Bischoff, Malte von Scheven, Bastian Oesterle (Hrsg.) Berichte der Fachtagung Baustatik – Baupraxis 14, 23. und 24. März 2020, Universität Stuttgart. https://doi.org/10.18419/opus-10762
  7. Böhm, M., Wagner, J., Steffen, S., Gade, J., Geiger, F., Sobek, W., Bischoff, M., & Sawodny, O. (2020). Input modeling for active structural elements – extending the established FE-Workflow for modeling of adaptive structures. IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM), 1595--1600. https://doi.org/10.1109/AIM43001.2020.9158996
  8. Geiger, F., Gade, J., von Scheven, M., & Bischoff, M. (2020). A Case Study on Design and Optimization of Adaptive Civil Structures. Frontiers in Built Environment, 6, 94. https://doi.org/10.3389/fbuil.2020.00094
  9. 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
  10. 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
  11. Fröhlich, B., Gade, J., Geiger, F., Bischoff, M., & Eberhard, P. (2019). Geometric element parameterization and parametric model order reduction in finite element based shape optimization. Computational Mechanics, 63, 853–868. https://doi.org/10.1007/s00466-018-1626-1
  12. Fröhlich, B., Geiger, F., Gade, J., Bischoff, M., & Eberhard, P. (2018). Model order reduction of coupled, parameterized elastic bodies for shape optimization. IUTAM Symposium on Model Order Reduction of Coupled Systems, May 22–25, 2018, Stuttgart, 151--163. https://doi.org/10.1007/978-3-030-21013-7_11
  13. Weidner, S., Kelleter, C., Sternberg, P., Haase, W., Geiger, F., Burghardt, T., Honold, C., Wagner, J., Böhm, M., Bischoff, M., Sawodny, O., & Binz, H. (2018). The implementation of adaptive elements into an experimental high-rise building. Steel Construction, 11, 109–117. https://doi.org/10.1002/stco.201810019

Contact:

This image shows Tamara Prokosch

Tamara Prokosch

M. Sc.

Scientific Staff

This image shows Lisa-Marie Krauß

Lisa-Marie Krauß

M. Sc.

Scientific Staff

This image shows Malte von Scheven

Malte von Scheven

Dr.-Ing.

Deputy Head of Institute

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