Effect of Crease Curvature on Bending Stiffness in Curved Crease Origami

Understanding the structural advantages of curved-crease origami is important in design optimization of space structures such as solar arrays and communications antennas, as the mechanical behavior of curved creases can vary with their curvature. This paper focuses on the effect of crease curvature on the bending stiffness of curved creases. The study encompasses quasi-static folding experimental studies on curved-crease specimens with different crease radii and flat specimens with different widths made of 80 gsm printer paper. The results demonstrate that the initial bending stiffness of curved-crease specimens with a low crease radius is lower but becomes higher at the maximum folded state compared to specimens with a high crease radius. Additionally, it can be observed that the contribution of the unrestrained half of the specimen significantly increases the bending stiffness of a curved crease specimen during the folding motion for lower crease radius, whereas the contribution remains almost constant for higher crease radius. Numerical models of curved creases, developed using the commercial software Abaqus and incorporating straight crease characteristics, accurately estimate experimental reaction forces, indicating that the characteristics of straight creases can be used in modeling curved creases.