For lightweight, thin-walled structures, like membranes, also geometrical form finding can be formulated as an optimization problem. In this case, besides mathematical methods, often experimental methods are used. A global optimum can usually not be found at all, or at best just for one single, dominating load case. For multiple load cases and their combinations, optimal compromises (like a Pareto optimum) may be found via multi-criteria optimization. Besides its geometric shape, also the topology of a structure can be subject to optimization.
Ultra-lightweight construction with adaptable structures offers the possibility to create optimal conditions for different situations and varying conditions. Different scenarios can evolve, for instance, from different loading conditions but also from different requirements (objective functions and the language of optimization) and varying system properties. Passive constructions lack such flexibility and adaptivity therefore hardly play a role in established optimization methods.
For the notion of optimization in this context it is important to distinguish between optimization of system behaviour via adaptation and optimization of the adaptive system as a whole. Our targets are therefore further development of established methods and development of new approaches for form finding as well as shape and topology optimization for adaptive structures.
The aim of project A04 is to improve existing methods and develop new approaches that allow to design and optimize shape and topology of adaptive structures. The following challenges and aims can be identified:
- How can form finding methods be enhanced to obtain more general system finding methods?
- Further development of methods for assessment, quantification and optimization of discrete and distributed adaptivity of engineering structures.
- Extension and transfer of analytical and numerical optimization methods to adaptive structures.
- How do these methods perform in terms of efficiency and robustness, exemplified via application to the Stuttgart SmartShell?
- Which role play uncertainties, imperfections and structural modifications during service life in the context of adaptation?
This research project considers the adaptable system within a holistic system optimization strategy. Besides thin-walled structures, like membranes and skins, also their combinations with beam and truss structures are analyzed.
The scientific aims do not particularly focus on development of optimization algorithms. Instead, it is of utmost importance to find a feasible formulation of optimization problems taking into account the aspect of adaptability and adaptivity. Thus, important methodological foundations are laid for innovative methods for design and construction of adaptive structures as new archetypical systems in civil engineering, independent of specific algorithms used for solution of optimization problems.
While further developing existing concepts, project A04 connects theoretical and methodological work with experimental methods and their practical realization. There is a vital mutual exchange of relevant information with many other projects within CRC 1244.
- Prof. Dr.-Ing. habil. Manfred Bischoff, Institute for Structural Mechanics
- Prof. Dr.-Ing. Dr.-Ing. E. h. Dr. h. c. Werner Sobek, Institute for Lightweight Structures and Conceptual Design