Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases....Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases.The crease design is often derived from experience and inspiration,so it is crucial to have a systematic approach to crease design.In this paper,a novel synthesis approach based on graph theory is proposed,which effectively addresses the challenge of designing the creases in origami mechanisms.The essence of this method lies in the acquisition of the double symmetrical crease pattern through the directed graph product operation of two subgraphs.The crease pattern can be simplified by employing a technique that eliminates certain creases while preserving the non-isomorphism and symmetry of the pattern.An improved mixed-integer linear programming model is developed to achieve an automatic distribution of the peak_valley creases of the origami.The proposed method ultimately generates 12 unique double symmetrical crease patterns.The new method proposed in this paper,through systematic design,significantly improves the efficiency of mechanism design while opening up broad prospects for exploring new mechanism structures,thereby greatly expanding its application potential in cutting-edge fields such as aerospace engineering and intelligent robots.展开更多
Multi-stable origami structures and metamaterials possess unique advantages and could exhibit multiple stable three-dimensional configurations,which have attracted widespread research interest and held promise for app...Multi-stable origami structures and metamaterials possess unique advantages and could exhibit multiple stable three-dimensional configurations,which have attracted widespread research interest and held promise for applications in many fields.Although a great deal of attention has been paid to the design and application of multi-stable origami structures,less knowledge is available about the transition sequence among different stable configurations,especially in terms of the fundamental mechanism and the tuning method.To fill this gap,with the multi-stable dual-cell stacked Miura-ori chain as a platform,this paper explores the rules that govern the configuration transition and proposes effective methods for tuning the transition sequence.Specifically,by correlating the energy evolution,the transition paths,and the associated force-displace-ment profiles,we find that the critical extension/compression forces of the component cells play a critical role in governing the transition sequence.Accordingly,we summarize the rules for predicting the transition sequence:the component cell that first reaches the critical force during quasi-static extension or compression will be the first to undergo a configuration switch.Based on these findings,two methods,i.e.,a design method based on crease-stiffness assignment and an online method based on internal pressure regulation,are proposed to tune the stability profile and the transition sequence of the multi-stable origami structure.The crease-stiffness design approach,although effective,cannot be employed for online tuning once the prototype has been fabricated.The pressure-based approach,on the other hand,has been shown experimentally to be effective in adjusting the constitutive force-displacement profiles of the component cells and,in turn,tuning the transition sequence according to the summarized rules.The results of this study will advance the state of the art of origami mechanics and promote the engineering applications of multi-stable origami metamaterials.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52375028,52205040)Hebei Provincial Natural Science Foundation(Grant Nos.E2024203052,E2024203105)Science and Technology Project of Hebei Education Department(Grant No.QN2023206).
文摘Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases.The crease design is often derived from experience and inspiration,so it is crucial to have a systematic approach to crease design.In this paper,a novel synthesis approach based on graph theory is proposed,which effectively addresses the challenge of designing the creases in origami mechanisms.The essence of this method lies in the acquisition of the double symmetrical crease pattern through the directed graph product operation of two subgraphs.The crease pattern can be simplified by employing a technique that eliminates certain creases while preserving the non-isomorphism and symmetry of the pattern.An improved mixed-integer linear programming model is developed to achieve an automatic distribution of the peak_valley creases of the origami.The proposed method ultimately generates 12 unique double symmetrical crease patterns.The new method proposed in this paper,through systematic design,significantly improves the efficiency of mechanism design while opening up broad prospects for exploring new mechanism structures,thereby greatly expanding its application potential in cutting-edge fields such as aerospace engineering and intelligent robots.
基金supported by the National Key Research and Development Program ofChina(Grant No.2020YFB1312900)the National Natural Science Foundation of China(Grant Nos.12272096,11932015)the Shanghai Pilot Program forBasicResearch-Fudan University 21TQ1400100-22TQ009.
文摘Multi-stable origami structures and metamaterials possess unique advantages and could exhibit multiple stable three-dimensional configurations,which have attracted widespread research interest and held promise for applications in many fields.Although a great deal of attention has been paid to the design and application of multi-stable origami structures,less knowledge is available about the transition sequence among different stable configurations,especially in terms of the fundamental mechanism and the tuning method.To fill this gap,with the multi-stable dual-cell stacked Miura-ori chain as a platform,this paper explores the rules that govern the configuration transition and proposes effective methods for tuning the transition sequence.Specifically,by correlating the energy evolution,the transition paths,and the associated force-displace-ment profiles,we find that the critical extension/compression forces of the component cells play a critical role in governing the transition sequence.Accordingly,we summarize the rules for predicting the transition sequence:the component cell that first reaches the critical force during quasi-static extension or compression will be the first to undergo a configuration switch.Based on these findings,two methods,i.e.,a design method based on crease-stiffness assignment and an online method based on internal pressure regulation,are proposed to tune the stability profile and the transition sequence of the multi-stable origami structure.The crease-stiffness design approach,although effective,cannot be employed for online tuning once the prototype has been fabricated.The pressure-based approach,on the other hand,has been shown experimentally to be effective in adjusting the constitutive force-displacement profiles of the component cells and,in turn,tuning the transition sequence according to the summarized rules.The results of this study will advance the state of the art of origami mechanics and promote the engineering applications of multi-stable origami metamaterials.
