Automated draping analysis of 3D printed flexible isogrid structures for textile applications

Fused filament fabrication (FFF) 3D printing can be used for manufacturing flexible isogrid structures. This work presents a novel draping analysis of flexible 3D printed isogrids from thermoplastic polyurethane (TPU) using image processing. A small-scale multi-camera automated draping apparatus (ADA) is designed and used to characterize draping behavior of 3D printed isogrid structures based on draping coefficient (DC) and mode. Circular specimens are designed and 3D printed that accommodate up to eight additional weights on their perimeters to enhance draping. Five infill patterns, three infill percentages, and three loading cases are explored to evaluate their impact on specimens' draping coefficient and mode, resulting in 45 tests. The range of DCs in this study is 21.9% to 91.5%, and a large range of draping modes is observed. For the lowest infill percentage, specimen mass is not the sole contributor to the DC values and the infill pattern has a significant impact for the three loading cases. Considering draping modes, the maximum number of convex and concave nodes observed for 25% infill specimens with added weights is three. The draping behavior characterization developed in this study can be followed to design and 3D print new flexible isogrids with textile applications.