Abstract：Origami spring structure is a simple origami structure，which is obtained by folding two long paper strips of the same size and gluing them to each other. It has received a lot of attention because of its multi-mode large deformation ability.In this paper，the multi-mode deformation capability and mechanical properties of the origami spring structure are studied experimentally，including the axial stretch-twist-coupling deformation and the bending deformation in all directions.Two bending modes，namely vertex-to-vertex bending and side midpoint-to-midpoint bending of the side，are found.The results show that the force-displacement curves of the bending process are approximately linear，but there are obvious jumps in the force-displacement curves of some of the bending experiments，which corresponds to the snap-through transition of the bending facet.To explain the above phenomena，we introduce virtual creases on the facet. Based on the different combinations of mountain and valley folds of virtual creases，a single origami spring cell exhibits four geometrically different configurations.The kinematic model of the rigid folding of the origami spring structure is obtained by deriving the displacement transformation matrix of the vertex coordinates based on the stacking of rotation and translation between cell.This model can describe all deformation modes of the origami spring structure.The potential energy constitutive landscape and the constitutive profile of the force-displacement relation for different deformation modes are clarified by specifying the torsional stiffness at the crease and based on the principle of minimum potential energy.The nonlinear axial stretch-twist-coupling deformation characteristics and linear bending deformation characteristics in all directions of origami spring structure are also qualitatively verified.The findings of this paper contribute to the design and development of origami robots with three-dimensional deformation and locomotion capability.
2023, Vol. 44 
