Analysis of dynamic process of thick-panel origami structures based on finite particle method

Origami structures are widely used in engineering fields, but the thickness of origami structures cannot be ignored in practical engineering. The folding and unfolding motions of thick-panel origami structures involve the coupling of structural deformation and rigid-body motion, and the contact constraints between thick panels are complex. In this study, a novel method for the dynamic process of thick-panel origami structures is proposed based on the finite particle method (FPM). Firstly, the fine modeling and simplified modeling of thick-panel origami structures are presented. Specifically, the fine modeling adopts a particle-solid model while the simplified modeling uses a particle-bar-spring model. Subsequently, hexahedral element and bar element adopted to model thick panels are briefly introduced. Bar-to-bar spring element is developed to maintain the shapes of thick panels in the particle-bar-spring model. Surface-to-surface spring element is improved to provide the driving forces at creases. Surface-to-surface contact element is also derived to consider the contact constraints between thick panels. Validations including two quantitative validations with experiments are conducted to verify the effectiveness of the proposed method. The dynamic processes of two typical thick-panel origami structures, i.e., the symmetric four-crease circular thick-panel origami structure and the compact-folding thickpanel origami structure, are modeled and analyzed, and the influence of panel stiffness on the dynamic process of the latter thick-panel origami structure is discussed in depth. The corresponding physical prototypes are also manufactured to provide qualitative validations of the proposed numerical framework.