8. Designing and Prototyping Adaptive Structures—An Energy-Based Approach Beyond Lightweight Design

This chapter presents an overview of an original methodology to design optimum adaptive structures with minimum whole-life energy. Structural adaptation is here understood as a simultaneous change of the shape and internal load-path (i.e. internal forces). The whole-life energy of the structure comprises an embodied part in the material and an operational part for structural adaptation. Instead of using more material to cope with the effect of rare but strong loading events, a strategically integrated actuation system redirects the internal load path to homogenise the stresses and to keep deflections within limits by changing the shape of the structure. This method has been used to design planar and spatial reticular structures of complex layout. Simulations show that the adaptive solution can save significant amount of the whole-life energy compared to weight-optimised passive structures. A tower supported by an exo-skeleton structural system is taken as a case study showing the potential for application of this design method to architectural buildings featuring high slenderness (e.g. long span and high-rise structures). The methodology has been successfully tested on a prototype adaptive structure whose main features are described in this chapter. Experimental tests confirmed the feasibility of the design process when applied to a real structure and that up to 70% of the whole-life energy can be saved compared to equivalent passive structures.