An Integrated Modelling and Toolpathing Approach for a Frameless Stressed Skin Structure, Fabricated Using Robotic Incremental Sheet Forming

Abstract

For structural assemblies that depend upon robotic incremental sheet forming (ISF) the rigidity, connectivity, customization and aesthetics play an important role for an integrated and accurate modeling process. Furthermore, it is critical to consider fabrication and forming parameters jointly with performance implications at material, element and structural scales. This paper briefly presents ISF as a method of fabrication, and introduces the context of structures where the skin plays an integral role. It describes the development of an integrated approach for the modelling and fabrication of Stressed Skins, an incrementally formed sheet metal structure. The paper then focus upon the use of prototypes and empirical testing as means to inform digital models about fabrication and material parameters including: material forming limits and thinning; the parameterisation of macro and meso simulations with calculated and observed micro behaviour; the organisation and extraction of toolpaths; and rig setup logics for fabrication. Finally, the validity of these models is evaluated for structural performance, and for geometric accuracy at multiple scales.