Study on the Hysteresis Performance of Notch-Type Compliant Joints Based on Experimental and Finite-Element Simulation

Abstract

The incorporation of origami-inspired structures in mechanical engineering has garnered significant attention due to their high efficiency and versatile deformation capabilities. In engineering applications such as energy-absorbing metallic origami metamaterials, the compliant joints between facets need to be weakened to ensure folding flexibility and reusability. However, the performance of different weakening strategies requires thorough investigation. This study presents both experimental and finite-element analyses of the mechanical properties of three notch-type deployable compliant joints: groove, elliptical holes, and rectangular holes. The research evaluates the repeated folding/unfolding performance, using folding force, deployable force, and stiffness as indicators of nonlinear mechanical behavior. Additionally, the hysteretic behavior is assessed by comparing the hysteresis loop areas of joints with various geometric parameters. The results demonstrate that geometric parameters, weakened volume, and crease cross-sectional area significantly affect folding and deployable performance as well as hysteretic behavior. An existing lamina emergent torsional (LET) joint is used as a reference for comparison. Our findings indicate that all three notch-type compliant joints exhibit superior hysteretic behavior. Specifically, folding force and deployable stiffness are directly proportional to the weakening volume and crease cross-sectional area, whereas the type of notched-compliant joint primarily determines hysteretic behavior. This research provides a foundation for advanced engineering applications, including reconfigurable structures and adaptive systems, which are critical for future innovations in structural engineering.