Structures that adapt to loads through large shape changes: design and optimization

The construction industry is a major contributor to the consumption of mined material resources and to the global energy demand. It is thus important to consider energy and material efficiency criteria for the design of civil structures. Through sensing and actuation, structures can adapt their geometry and internal forces in order to maintain optimal performance during service life. Previous work has shown that well designed adaptive structures achieve substantial whole-life energy savings compared with passive structures. Whole-life energy consists of an embodied part in the material and an operational part for structural adaptation. This paper presents a new method to design structures that adapt to loads through large shape changes in order to redistribute stresses and thus to minimize material utilization. This method consists of two parts: (1) shape optimization is employed to obtain shapes that are optimal under each load case. This way extreme loads that typically have long return periods do not govern the design. (2) Stochastic search combined with the nonlinear force method (NFM) is employed to obtain an optimal actuation system that is able to control the structure into the target shapes obtained in (1). A 3D-truss roof structure is taken as a case study to illustrate the design process.