•Novel designing of deployable curved-surface rigid origami flashers is proposed.•Design method of planar origami flashers with different central hubs is presented.•Planar origami flashers are ...parallelly projected on target spherical surfaces.•Flexible and elastic hinges are used to obtain thick-panel rigid origami flashers.
This paper proposes an approach to designing rigid origami flashers that can be deployed onto curved-surface configurations. The method of designing planar origami flashers that can be wrapped around regular polygonal central hubs is presented. Based on the principle of parallel projection, planar origami flashers are projected onto target spherical surfaces to obtain the vertices on the boundary creases between sections of adjacent origami flashers. The geometric relationships of thin-panel curved origami flashers are established in terms of foldability, and other vertices in each section are calculated using numerical methods. Flexible and elastic hinges modify the thin-panel curved origami flashers into thick-panel rigid flashers. The thick rigid panels maintain the shape of flashers, and the flexible creases treated using thickness-accommodating methodologies are used to maintain the foldability of the thick panels. Additionally, we analysed the parameters that affect the accuracy of the surface fitting. The feasibility of the proposed approach is verified using numerical simulations and physical prototypes. The novel designing of deployable curved-surface rigid origami flashers facilitates their potential applicability in solid surface antennas, surface reflectors, and other space engineering applications.
Origami cylinders have been studied extensively under compression, however, their normal force response under shear deformation is still ill-understood. We experimentally studied the shear-induced ...normal force of these systems and provided a simple model to predict this response in Yoshimura and Kresling origami cylinders in the range of small deformations. Besides that, the effect of disorder is little understood in those origami patterns. Therefore, we investigate the disorder effect and show it can lead to diverse normal responses perpendicular to shear deformation in crumpled Yoshimura, with slopes of the force perpendicular to torsion that can be positive, zero, or negative depending on the disordered pattern of folds. The disorder leads to an asymmetry concerning the shearing direction, which we quantified via an asymmetry index from the 2D Fast Fourier transform spectrum of the crease pattern images. This asymmetry index is found to be linearly related to the slope of the normal force-torsion relationship.
•The Poynting effect of origami bellows can be tuned by rational design of patterns.•Disorder can lead to various perpendicular-to-shear deformation responses in semi-ordered structures.•Effect of imperfections is better understood by studying the shear-induced normal response than the compression or shear response.•Image analysis of crumpled bellows reveals correlations between shear-induced normal response and structural asymmetry.
Inflatable Origami
In article number 2201891, Katia Bertoldi and co‐workers take inspiration from origami to create inflatable structures that deploy in intricate, distinct ways using only one ...pressure signal. The building blocks of the system are modified, bistable versions of the Kresling motif, which can be assembled (as shown here) to unlock complex shapes and deformations that can be pre‐programmed.
Origami‐based designs refer to the application of the ancient art of origami to solve engineering problems of different nature. Despite being implemented at dimensions that range from the nano to the ...meter scale, origami‐based designs are always defined by the laws that govern their geometrical properties at any scale. It is thus not surprising to notice that the study of their applications has become of cross‐disciplinary interest. This article aims to review recent origami‐based applications in engineering, design methods and tools, with a focus on research outcomes from 2015 to 2020. First, an introduction to origami history, mathematical background and terminology is given. Origami‐based applications in engineering are reviewed largely in the following fields: biomedical engineering, architecture, robotics, space structures, biomimetic engineering, fold‐cores, and metamaterials. Second, design methods, design tools, and related manufacturing constraints are discussed. Finally, the article concludes with open questions and future challenges.
This article reviews the state of the art of origami‐based applications in engineering. Publications of origami‐based applications are reviewed according to the following fields: biomedical engineering, architecture, robotics, space structures, biomimetic engineering, fold‐cores, and metamaterials. Design methods and tools are also reviewed. Manufacturing considerations are provided and future challenges discussed.
•An overview of origami-inspired systems and structures is presented discussing the fundamentals, applications and modeling.•The construction of origami reduced-order models based on kinematic-based ...approach and symmetry hypotheses is discussed.•Kinematic-based approach is treated using either equivalent mechanisms or direct geometric analysis, establishing a procedure to build reduced-order models based on rigid origami theory.•Finite element analysis (FEA) is discussed for a complete investigation including panel deformations during folding process, furnishing a range of validity for reduced-order models.•Nonlinear dynamics of origami systems is discussed as an application of the use of reduced-order models showing rich and complex behaviors.
Origami is inspiring several fields of knowledge such as engineering, aerospace systems, medicine, and biomechanics, motivating the creation of novel adaptive and morphing systems and structures where smart materials are employed for actuation. The combination of low energy processes and inherent foldability allows the design of optimized systems widely applicable, ranging from nanoscale to megascale. This article deals with a general overview of the mechanical description of origami-inspired systems and structures, discussing their fundamentals, applications and modeling approaches. A critical review of the mechanical modeling is discussed considering either kinematic-based or mechanic-based formulations. A collection of results is reported to allow a comparison of the best strategies to deal with the complex behavior of origami systems and structures. Kinematic-based formulations are presented with a special interest on developing reduced-order models. Equivalent mechanisms and direct geometric approaches are treated exploring symmetry hypotheses as the basis to build proper reduced-order models. Mechanic-based formulations are treated as a reference description using finite element analysis. The comparison of the different descriptions allows one to establish reduced-order model range of validity, which is a powerful tool for design purposes. Nonlinear dynamics of origami systems and structures are reviewed exploiting the use of reduced-order models. A rich and complex behavior originated from the combination of geometrical and constitutive nonlinearities is stated.
Display omitted
Thin sheets have long been known to experience an increase in stiffness when they are bent, buckled, or assembled into smaller interlocking structures. We introduce a unique orientation for coupling ...rigidly foldable origami tubes in a “zipper” fashion that substantially increases the system stiffness and permits only one flexible deformation mode through which the structure can deploy. The flexible deployment of the tubular structures is permitted by localized bending of the origami along prescribed fold lines. All other deformation modes, such as global bending and twisting of the structural system, are substantially stiffer because the tubular assemblages are overconstrained and the thin sheets become engaged in tension and compression. The zipper-coupled tubes yield an unusually large eigenvalue bandgap that represents the unique difference in stiffness between deformation modes. Furthermore, we couple compatible origami tubes into a variety of cellular assemblages that can enhance mechanical characteristics and geometric versatility, leading to a potential design paradigm for structures and metamaterials that can be deployed, stiffened, and tuned. The enhanced mechanical properties, versatility, and adaptivity of these thin sheet systems can provide practical solutions of varying geometric scales in science and engineering.
•Energy analysis of four-fold origami structures are extended to deal with complex geometries.•Multi-stable configurations of double-corrugated origami tessellations with reduced symmetries are ...determined.•Theoretical formulas obtained for non-prestressed configurations are verified by finite element models.•Our results facilitate the precise design and customization of multi-stable origami structures.
Origami-inspired structures can manifest a range of interesting characteristics such as reconfigurability and multi-stablity. Theoretically, the energy of rigid-foldable origami structures is a result of deformations in their creases. Although the multi-stability of the classic double-corrugated origami (or the Miura-ori) has been studied extensively, the energy variation analysis of its generalized derivatives such as those with less symmetric unit fragments need to be further investigated. Here, we derive the general energy equations and study the multi-stability behavior of certain low-symmetry double-corrugated origami tessellations. In particular, studies on the double-corrugated origami pattern with maximally asymmetric octagonal unit fragments are extended from our previous research on the design of two-dimensional patterns to their deformation and energy analyses in the three-dimensional space. We demonstrate that a reasonable selection of initial design configuration parameters can enable the corresponding origami structure to be multi-stable, on condition that appropriate pre-stresses are introduced to the crease pattern. We also derive the energy equations of non-prestressed origami structures with the abovementioned geometric design specifications. In addition, the obtained theoretical formulas are verified by finite element models, as well as against some previously reported results for the classical Miura-ori. The findings of this study enable the precise customization of multi-stable origami design configurations and facilitate the development of more complex origami structures.
Display omitted
Single-loop elastic rings can be folded into multi-loop equilibrium configurations. In this paper, the stability of several such multi-loop states which are either circular or straight are ...investigated analytically and illustrated by experimental demonstrations. The analysis ascertains stability by exploring variations of the elastic energy of the rings for admissible deformations in the vicinity of the equilibrium state. The approach employed is the conventional stability analysis for elastic conservative systems based on the second variation of the system energy which differs from most of the analyses that have been published on this class of problems, as will be illustrated by reproducing and elaborating on several problems in the literature. In addition to providing solutions to two basic problems, the paper analyses and demonstrates the stability of six-sided rings, curved-sided hexagrams, that fold into straight configurations.
PDF
