Type Of Deployable Structures Research Articles

Hybrid origami-linkage vaulted deployable structures: parametric development and form-finding

AbstractThe demand for adaptable structures is steadily increasing in contemporary architectural practice. Deployable structures, characterized by their flexibility and versatility, offer innovative solutions across demanding engineering and architectural contexts. Among the various types of deployable structures, two main categories emerge: lattice deployable structures and continuous surface deployable structures. This paper explores the creation of hybrid deployable vaulted structures by incorporating kinetic elements from both deployable structure categories. A combination of rigid thick origami surfaces and retractable structural frames composed of four-bar and scissor-hinged linkages is examined, while both direct and inverse design methodologies are explored. To facilitate the parameterization and kinematic study of the proposed structures, an algorithm is developed within the Rhino Grasshopper visual programming environment, which is then utilized for form-finding and design optimization of the generated deployable vaults. The present study aims to contribute to the evolution of lightweight, kinetic elements for versatile architectural applications. The proposed hybrid deployable structures are designed to adjust to evolving spatial and functional requirements while maintaining structural integrity.

Simulation of Dynamics During Deployment of Foldable Origami Structures

Foldable origami-based structures are a type of deployable structures that are increasingly applied in the space and building industries. When folded, the small size of such structures facilitates transportation and storage. Meanwhile, the properties of their larger deployed state may be of interest to different applications. A stable working condition is established by locking the structure in its deployed state, as in the process of deployment, the driving forces may generate a dynamic effect, thus leading to instability of the system. Hence, the study of dynamic characteristics of such structures, including trajectory, duration, velocity, and acceleration is of paramount importance. In this paper, based on the general dynamic equation and Lagrange’s equations of the first kind, the finite element method is adopted to investigate the dynamic deployment of foldable plate structures in terms of the generalized nodal coordinates. The proposed geometric description of a quadrilateral plate element is based on a folding plate composed of refined triangular elements, which are used to approximate the real shells in the structure. Subsequently, a MATLAB framework is developed on the basis of the element using the Newmark integration and the Newton–Raphson iteration method to simulate the deployment process of the structure. Comparisons between MATLAB results and ADAMS results verify the reliability of the framework in analyzing the dynamic deployment of the foldable origami-based structures with sufficient accuracy.

Weight and Material Optimization of Scissor-hinge Linkages According to Given Span Length

Scissor-hinge linkages are one type of deployable structures which are mostly used in architectural and engineering applications due to their transformation capabilities and the advantages of ease of erection and dismantling. For hundreds of years, these linkages have been used in wide range of applications such as deployable roof structures, bridges, shells, pavilions, emergency shelters, furniture design and satellite equipment. Scissor-hinge linkages have different primary units depending on the geometry of the bars and the location of the pivot point, which are called as polar, translational, and angulated. Geometry and dimensions of these primary elements directly affect the geometry and the weight of the whole structure. This study aims to investigate the relationship between the span length, geometry of the primary units, cross section of the bars and the material of the scissor-hinge linkages by means of genetic algorithms. In detail, a structural and geometric optimization is made in order to obtain the lightest geometric configuration for the given span lengths while keeping the structural strength and stability by altering typology, dimensions, number of the primary units and material parameters. To achieve that a multi-objective genetic algorithm based optimization approach is utilized. Generative model is created in Grasshopper® parametric design software. The structural performances of the generated solutions are evaluated with the help of Karamba3D that is a parametric structural tool for Grasshopper. Optimization of the problem is performed via multi objective genetic optimization plug-in named Octopus.

Mechanism Design with Singularity Avoidance of Crystal-Inspired Deployable Structures

Although deployable structures have important applications in various fields, developing a new form of structural configuration faces some scientific challenges. Furthermore, kinematic singularity frequently exists in these structures, which has a negative impact on deployment performance and stiffness. To deal with these problems, this paper obtains inspiration from crystals on two-dimensional (2D) space, and aims at developing symmetric deployable structures assembled by identical link members and periodic units. Mobility and compatibility conditions of crystal-inspired deployable structures are given, and a detailed design for novel joints with bevels gears is proposed to avoid singularity of these symmetric structures. According to feasible solutions to the compatibility conditions, several types of deployable structures are developed and verified to be mobile with a single degree of freedom. The results show that the proposed joint with bevel gears has a satisfactory singularity avoidance capability, and the assembled structures exhibit a good deployment performance. Because a crystal-inspired deployable structure can be gradually deployed to cover a large area, it has a potential engineering application as a macroscopic or mesoscale structure.

Vibration analysis of a deployable structure using Constant-Q nonstantionary Gabor transform and Fourier transform

Deployable structures are so widely employed in spacecraft, which are folded during launch to fit inside the launcher's payload fairing and deployed to be the structures on-orbit. In order to more accurately obtain vibration properties of the solar arrays with joint clearances, a set of experiment device is developed, and vibrations of the deployable structure are stimulated by means of hammer impact method. Constant-Q nonstationary Gabor frame transform and Fourier transform are described and employed to analyze vibration properties of the deployable structure. It is found that the damping becomes greater along with the vibration frequencies increasing, and the energy of vibration of the outer panel tends to distribute in more frequencies in contrast with the inner panel. Compared with the deployed state, a more serious wide-frequency phenomenon occurs in the folded situation, which indicates that the effect of the clearance is stronger in the folded situation. It is shown that the vibration analysis using Constant-Q nonstationary Gabor transform and Fourier transform is helpful to reveal dynamic performance of this type of deployable structures.

Mobility and Kinematic Analysis of Foldable Plate Structures Based on Rigid Origami

As one new type of deployable structures, foldable plate structures based on origami are more and more widely used in aviation and building structures in recent years. The mobility and kinematic paths of foldable origami structures are studied in this paper. Different constraints including the rigid plate, spherical joints, and the boundary conditions of linkages were first used to generate the system constraint equations. Then, the degree-of-freedom (DOF) of the foldable plate structures was calculated from the dimension of null space of the Jacobian matrix, which is the derivative of the constraint equations with respect to time. Furthermore, the redundant constraints were found by using this method, and multiple kinematic paths existing in origami structures were studied by obtaining all the solutions of constraint equations. Different solutions represent different kinematic configurations. The DOF and kinematic paths of a Miura-ori and a rigid deployable antenna were also investigated in detail.

816 弾性折りを利用した展開構造の設計

As represented by Miura-ori, origami has inspired various types of deployable structures. Usually, these Origami structures are designed under the assumption of "rigid folding", which means each plane is undeformable and connected with ideal joints. In this study, a new strategy for designing deployable structures are proposed by using partially elastic origami models. These new origami structures take into account the elastic deformation. It enables us to estimate the elastic energy through folding and unfolding process and to design self-deploying origami structures.

Recent advances in configurations in spatial structures

This paper presents a summary of the author's recent work on the configuration of spatial structures. To better satisfy architecture and engineering requirements, the paper introduces a technique of reconstructing freestyle 3D objects with grid space structures. With this technique, irregular and complex configurations can be easily modelled, which has a great potential in modelling of sculptures and bionic structures. Then several new types of deployable structures, which are based on linkage mechanisms including Bricard linkages and double chain linkages, are proposed. The kinetic behaviour of these deployable structures is investigated by geometrical analysis. And their possible applications in retractable roofs are also explored. Meanwhile, the paper proposes a practical application of structures with changeable configurations – a novelty erection technology based on expandable mechanisms. Finally, the paper presents some new advances in form-finding of tensegrity structures and shape control of tensegrity structures.

Cable-Stiffened Pantographic Deployable Structures Part 2: Mesh Reflector

The general concept of deployable structures based on pantographs that are deployed and stiffened by means of cables is applied to the design of the support structure for a large mesh reector. The two main components of this structure are a cable-stiffened pantographic ring that deploys and pretensions a cable network that, in turn, provides a series of stiff, geometrically accurate support points to which a reective wire mesh orexible membranewould beconnected.Thepantographicring isahighly redundantstructurewith an internalmechanism that permits synchronous deployment without any strain in the rods. The geometric conditions that have to be satis® ed in order for an n-sided ring to fold without any strain are investigated, including the effects of joint size. An experimental model has been designed and tested. In the folded con® guration, it has a diameter of 0.6 m and height of 1.2 m; in the deployed con® guration, it has a diameter of 3.5 m. Stiffness and deployment tests on this model have shown its behavior to be linear and the maximum shape error to be § 0.3 mm. HIS paper is the second in a series that deals with a new type of deployable structures where a foldable bar structure, which consists of pairs of straight bars connected by pivots and forming a pantograph, is deployed and stiffened by two sets of cables, known as active and passive cables. The passive cables are short cable elements connected to joints of the pantograph that get farther apart during deployment,and the length of each passive cable is such that it becomes taut when the pantograph is fully deployed. The active cables are longer elements that run over small pulleys and whose overall length is controlled by one or more electric motors. The layout of these cables is such that deployment of the pantograph can be activated by shortening the length of at least one of the active cables.Oncethepantographisdeployed,andhenceallofthepassive cables are taut, it is possible to set up an overall state of prestress in