“…Establish a Cartesian coordinate system (0-xyi), where the origin O is located at the center of the bottom pentagon, the x axis runs through the node 1, and the z axis is normal to the bottom pentagon. As in Crane et al [23], we assume that the bars are rigid and have a length of 90 mm, and all strings are linear elastic. The top strings, bottom strings, and diagonal strings have the stiffnesses of 0.5 N/mm, 0.3 N/mm, and 0.4 N/mm, and the natural lengths of 35 mm, 45 mm, and 65 mm, respectively.…”