Experimental study on tensile properties of 3D printed flexible kirigami specimens

Fused Filament Fabrication (FFF) is one of the most popular 3D printing processes that can be used to manufacture flexible parts. With the use of kirigami structures, the load-carrying capability and elongation of these parts can be significantly improved. In this work, we investigate the impact of stacking sequence, slit size, and thickness on the tensile properties of 3D printed flexible kirigami specimens. In addition, we demonstrate how the transition phenomenon and out-of-plane deformation can significantly improve percent elongation at their breaking point. Considering the deformed shape during testing, specimens with a combination of layers printed along and transverse to their length showed the highest tensile break strength and the percent break elongation (2.43 MPa and 183 %, respectively). It is also determined that the occurrence of the transition phenomenon depends on the specimen's thickness, and was observed for the 1 mm and 1.5 mm thick samples.