A new method to design structures that adapt to loads via large shape changes

The construction industry contributes to more than a third of the global energy demand and consumes almost half of all mined material resources. It is thus important to include energy and material efficiency criteria for the design of civil structures. Adaptive structures have potential to provide solutions; through sensing and actuation, their shape and internal forces are controlled to maintain optimal performance during service life. Previous work shows that adaptive structures can provide substantial whole-life energy savings compared with passive designs. 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 minimize material utilization. This method consists of two parts: (1) shape optimization is employed to obtain shapes that are optimal for each load case. This way extreme loads that typically have long return periods do not govern the design. (2) A new formulation based on stochastic optimization and the nonlinear force method (NFM) is employed to obtain optimal actuator layout and commands to control the structure into the target optimal shapes. A 3D-truss roof system is taken as a case study to illustrate mass and energy savings.