Design, Analysis, and Optimization of Negative Stiffness in a Kresling-Origami Rod-Hinged Truss

Negative stiffness is a unique mechanical phenomenon that arises during the elastic snap-through process after structural instability. It promotes motion, making it particularly advantageous in various specific applications such as damping amplifiers and quasi-zero stiffness isolators. However, to harness its benefits, it is crucial to design and control negative-stiffness structures with precision; otherwise, their introduction may pose risks of system instability, negating the intended advantages. Current negative-stiffness structures present challenges, including a narrow negative-stiffness region and strong nonlinearity, which complicate control. Therefore, this paper aims to explore a research method for a Kresling-origami-inspired negative-stiffness structure to enhance its negative-stiffness characteristics. First, the negative-stiffness characteristics of the Kresling-origami panel, the Kresling-origami rod-hinged truss, and the Kresling-origami beam-buckling structure are compared, highlighting the superiority of the rod-hinged truss in negative-stiffness design. Then, the displacement-rotation coupling motion equations for the rod-hinged truss are derived, the interference conditions during the truss’s motion process are established, and the impact of parameters on the negative-stiffness characteristic is investigated. Finally, the parameter optimization strategy is determined. The results demonstrate that the research method can precisely design the negative-stiffness value at the unstable static equilibrium point, improve the proportion of the negative-stiffness region over the entire stroke, and enhance the linearity and central symmetry of negative stiffness near the unstable static equilibrium point.