Concept Design of Variable Density, Flat Cut Active Bending Shells

Sustainable engineering design considers the lifecycle of structures, from material selection through design, manufacturing, erection, and beyond, to minimise environmental impact. This holistic approach is synergetic with innovative design methods that maximise structural efficiency. The bending-active approach is a form-finding design method that embraces efficiency and innovation in material use, manufacturing, transportation, and construction processes. Typically employed for the design of shell structures, it involves bending initially straight linear elements or flat surfaces within the elastic displacement boundaries of the material to achieve a desired shape or form. This method offers several advantages in terms of sustainability and cost savings. It minimises material waste because materials are directly shaped into the curved form; transportation is more sustainable because even significant shell elements can be efficiently transported on-site in their original, straight state. Leveraging the possibilities offered by 3D printing, this study introduces the integration of cut-out patterns within bending-active structures. These patterns are strategic interventions that serve integrated design goals, allowing for a harmonious blend of form and function. Their integration is feasible via subtractive and additive manufacturing techniques, with 3D printing minimising material waste. A novel pre-form-finding step is introduced to optimise the orientation and size of these cut-out patterns. This step is performed within a parametric design environment, enabling the seamless management of the new variables. This study shows how active bending structures can efficiently handle bending stress using material strip