Interactive Strain Mapping for Non-Rigid Folding Origami Structure

The focus of the current research is at developing a tool, which can provide more readily available information about the dynamic deformation behavior of the structure based on instantaneous average strain of each facet in the earlier design process. The aim is not to provide the most accurate strain as it requires greater resources, but to inform the relative strain levels in the facets at the instant time frames during the folding/unfolding process.
The current investigation started by considering origami structures with simple plane elements, and assumed that the edges are in full contact along the lengths. At the current stage of development, only in-plane deformations are considered.
The investigation first looked at the generation of origami pattern based on the user defined geometrical surface. For the given pattern, the origami structure is forced into an initial ‘fully unfolded state’. The geometrical profiles of each origami facets at the ‘fully unfolded state’ are set as the ‘0 state profiles’.
The geometrical configuration of the origami structure can be then interactively changed by moving a reference points or frames, or by ‘pulling’ the structure into specifically defined geometrical configurations. During the changes in the geometrical configuration of the origami element, any deformations of the individual facets are computed against the ‘0 state profiles’ for strain calculation.
In the last stage, the tool puts the simulated structure through an optimization process with minimum strain and number of facets as competitive fitness criteria, with the aim to provide a feedback to the designer on how the folding pattern can be improved.
The current paper includes the case of a stent fold, and the tool is developed in Grasshopper and Kangaroo platform, which are graphical algorithm plug-ins for Rhino 3D.