A Bar and Hinge Model for Simulating Bistability in Origami Structures With Compliant Creases

Active origami structures usually have creases made with soft and compliant plates because it is difficult to fabricate real hinges and actuate them. However, most conventional origami modeling techniques fail to capture these compliant creases and simplify them as concentrated rotational springs, which neglects torsional and extensional deformations of the creases. In this paper, an improved formulation of a bar and hinge model is proposed to explicitly capture the geometry and the flexibility of compliant creases with nonnegligible width in an origami, and the model is verified against finite element simulations. The verification shows that the model performs relatively well despite being simple and computationally inexpensive. Moreover, simulation examples demonstrate that the proposed model can capture the bistable behavior of the compliant crease origami with nonnegligible crease width because it explicitly includes the extensional stretching energy into the simulation framework and allows torsional crease deformations.