Deployable Structures

Dresden’s gateway to the skies: the world’s first streamlined airship hangar and its influence on architectural history

The Dresden municipal airship hangar built in 1913 is the first aerody- namic airship hangar of its kind and an archetypal design for all subse- quent streamlined airship hangars. For the first time, its construction and usage history is comprehensively presented, analysed and placed within its historical context. The focus point in the research paper is the dome-like revolving door as a new kind of architectural device, which is first exemplified by the Dresden airship hangar as well as the scaf- fold-free mounting technology using the hinge function of the support structure’s joints. The airship hangars in Liegnitz and Posen, which are contemporary and constructed in the same way, are also analysed and looked at in terms of architectural history.
The biography of civil engineer Ernst Meier (1868-1934), the previous- ly unknown creator of this type of airship hangar, is included and itself constitutes a significant outcome of the research. In contrast to the usu- al airship hangars of the time, the revolutionary innovation of Meier’s round-shaped hangar is shown, helping to place it within the devel- opment history of aerodynamics related to buildings, and in particular to airship hangars. Ernst Meier’s airship hangar shares the lot of many inventions ahead of their time and faced rejection. Fifteen years later, in 1929-30, Karl Arnstein builds an adapted version of Meier’s hangar in the USA by using his Dresden construction plans. The so-called Airdock, a new superlative in terms of size and engineering excellence, made the international breakthrough with its streamline shape and was a turning point in airship hangar design. Its formal influence on all airship hangar designs of the 1930s and 1940s until 2000 is internationally traceable and visible in numerous airship hangars and airship hangar projects in the USA, Spain, Brazil, Germany, the United Kingdom and the Soviet Union. The concluding part considers the last streamlined hangar built in 2000 in the formal architectural tradition of the Dresden archetype. A digression on event buildings with dome-like retractable roofs demon- strates their origin in the airship hangar’s dome-like revolving door and thereby their influence on architectural history overall.
The time frame represented here covers the short period of the giant Zeppelin airships of circa 1910 to the 1940s and extends to the construction of the CargoLifter airship dockyard in 2000.

The work from Emilio Pérez Piñero (Valencia, 1935-Torreblanca, 1972) was developed between the years 1961 and 1972 when he died in a car accident coming back from Figueres. When Emilio Pérez Piñero wins in London the contest for students, raised in the conference held by the International Union of Architects with the project called`movable Theatre´, Fuller is on the jury that awarded the first prize. He is impressed by the work of Piñero and talks to his colleague, Félix Candela who is in the jury too. After the competitions rules they should design a movable Theater where 500 persons could stay inside, and it had to be movable and transportable and not have a permanent site. He designed a theater that could be capable of being folded or unfolded in every direction. In London he presented a prototype in a 1/10 scale that was able to reproduce the movement of the roof. This first work of Pérez Piñero appears very important because it introduce him to the world and permit us to relate his work to the avant-garde movement that were working at the same time, that is the sixties of the past century. The prototype called as movable Theatre began a space journey in London when it took part of the competition of the International Union of Architects in 1961 and then it went to Germany where was exposed in the Spanish Center in Munich and showed in the University of Stuttgart in 1962. The same summer the model of a movable Theatre is going to take part of the Folding Domes Congress that it is going to take place in Tokyo in Japan. In order to shown the international importance and its impact of this first work of Pérez Piñero these travels around the world are going to be used and it permit us to relate the Spanish architect to the International movement of the decade. Through several concepts that are common to all these group it is going to be prove that the work of Pérez Piñero could be explain in such a stream from its design phase to its development. This journey begins in London and through the concepts of leisure and nomadic the relationships with Archigram and Cedric price are going to be explained. The prototype travelled to Germany in the cities of Munich and Stuttgart and this fact allow us to build bridges between the Spanish architect and the group called GEAM and some of their German components like Gunther Kühne and most known Schulze-Fielitz y Frei Otto. We can recognize that all of them used the geometry as design tool to create that what Yona Friedman named as Infrastructures. Finally as the model went to Japan we should think about the term that the Japanese group the Metabolist used too, those are metamorphosis and symbiosis. Thank to this spacey journey we can prove the importance of Pérez Piñeros work not only in the foldable structures but as a self-sufficient member of the main stream of the sixties. Thought the concepts that are common of the avant-garde architectural groups we could locate not only in time but in space the work of Emilio Pérez Piñero.

Origami folding structures can find significant applications in the general area of building design, as they can be lightweight and deployable. An inherent property of folded surfaces, which is related to the degrees of freedom of each origami crease pattern, is form flexibility. Therefore, when building-scale applications are considered, in many instances, the folded surfaces, in order to become stiff and load-bearing, need to be constrained. A study of different types of deployable structures has led to the observation that in planar scissor linkages, hinges and pivots follow the same deployment path in space, as sets of vertices in certain origami structures. Due to the similarities in their kinematic behavior, selected origami patterns and scissor linkages can function as effective kinematic pairs, leading to structures able to transform in a controlled manner through a wide range of possible spatial configurations. A few examples of combining these two types of structures already exist [1-3]. In this paper a systematic approach for coupling origami crease patterns characterized by biaxial and rotational symmetry, with translational, polar and an-gulated scissor linkages, towards the development of novel forms of deployable structures, has been attempted. For the design and evaluation of the kinematic performance of the developed new structures, existing geometric modeling and calculation methods, parametric and simulation processes , as well as testing with physical models have been used. It is anticipated that research in this direction will lead to promising novel hybrid types of deployable structures .

A Geodesic Fixed Dome can be packed into a bundle of 3 x 3 x 3 feet, considering its erection time, takes hours. A Collapsible Geodesic Dome reduces the amount of time required to erect it by a very large margin, which will be few seconds, but it consumes 2 times the material, 8 times the volume & 16 times the complexity than that of a Fixed Dome, we've built a Deployable Dome, which will consume less material, volume and erection time than that of a Collapsible or Fixed Geodesic Domes. So, the entire process went through experimenting with Fixed dome, Collapsible dome, Tensegrity structures, Transformable and Deployable structures as most of the collapsible structures required double the amount of material which can be reduced to a very extent that it would require less than that of fixed structure. This was at the end achieved by integrating cable systems such as double-cable trusses in the entire structure to achieve the same.

A novel and efficient approach to the design of foldable architectural structures based on rigid Origami is here proposed to obtain lightweight constructions. This kind of structures are made by rigid thin plates, easily assembled and transportable. In particular, a composed Origami in-plane structure is developed, testing two different typology of folding solutions. The model has been developed by applying parametric design, which allows to vary the geometric parameters to assess the sensitivity of the structural response, with the aim of finding the best structural morphology. Manufacturing issues have been integrated in this process to develop a feasible construction. Thin panels of composite material Hylite® have been considered as particularly interesting to develop a model in which panel's core material can provide a hinge function, suitable to be used for deployable structures.

Keywords:
Deployable structure, scissor-like structure, rigid-foldable origami, Jitterbug-like mechanism, overconstrained linkage, Sarrus linkage

Summary:
The field of transformable structures is remarkably varied since it transcends the borders of conventional disciplines and inscribes itself into the modern notion of adaptivity. The main aim of this thesis is to provide insight in the design of transformable structures on an architectural scale.
In the first part of the thesis, an extensive literature research is done to show the possibilities that lie in the hands of the designer. Geometrical variations are complemented by examples of real-life use of each of the addressed categories: scissor-like structures, rigid-foldable origami and Jitterbug-like mechanisms. Many of them are identified as being variations on overconstrained linkages.

The second part addresses the kinematic aspects such as the analysis of degrees of freedom and trajectories. A numerical model for a generalized deployable 4-bar structure is given. Materialization challenges and pitfalls in the scaling of transformable structures are further discussed, specifically joint design and actuation.

The third part focuses more deeply on the Sarrus linkage and the different arrays that can be formed from it. A novel way of introducing a polar angle in the Sarrus linkage by means of a joint offset is given. Furthermore, a novel array, dubbed the overlap array, is analyzed and its geometrical aspects discussed. A parametric tool for the design of flat and polar Sarrus arrays is given. The trade-off between deployability and structural performance of the arrays is discussed and two case studies finally are used to structurally analyze the different arrays.

To advance the use of geometric algebra in practice, we develop computational methods for parameterizing spatial structures with the conformal model. Three discrete parameterizations – symmetric, kinematic, and curvilinear – are employed to generate space groups, linkage mechanisms, and rationalized surfaces. In the process we illustrate techniques that directly benefit from the underlying mathematics, and demonstrate how they might be ap- plied to various scenarios. Each technique engages the versor – as opposed to matrix – representation of transformations, which allows for structure-preserving operations on geometric primitives. This covariant methodology facilitates constructive design through geometric reasoning: incidence and movement are expressed in terms of spatial variables such as lines, circles and spheres. In addition to providing a toolset for generating forms and transformations in computer graphics, the resulting expressions could be used in the design and fabrication of machine parts, tensegrity systems, robot manipulators, deployable structures, and freeform architectures. Building upon existing CGA-specific algorithms, these methods participate in the advancement of geometric thinking, leveraging an intuitive spatial logic that can be creatively applied across disciplines, ranging from time-based media to mechanical and structural engineering, or reformulated in higher dimensions.

Origami the ancient art of paper folding has a great effect now, not only on form generation process but also in the development of deployable mechanisms and mimicking the folding systems in nature especially with the great progress in the geometry of folding and computer simulation of the folding process. So, it gains a great interest in the field of adaptive architecture, designing open spaces and product design, as it is a source of inspiration for designing configurable structures useful for shed systems that can adapt with the changing in the surrounding climate conditions, people's needs and other surrounding environmental changeable conditions. Also, in the design of deployable products that could be packed easily in small spaces and get deployed when needed to save space and solve the contemporary problems of small multi-functional spaces. In this research, we try to suggest a methodology for designers to get benefit from this art in there designing process, depending on four main sections which are, literature review on the pioneers of this art, the basics of the geometry of folding, computer programs that help in simulating the process of folding and finally methods of fabrication of foldable structures. In the preview of previous studies in the field of architecture, analysis has been done with parameters of, static or dynamic, materials and type of folding lines, type of actuator in kinematic ones, and modularity.

This paper presents research on a hybrid structure system that extends the principles of active-deployed tensegrity structures through a series of prototypes that use inflatable compression struts. These structures combine the advantages of tensegrity and pneumatic structures, resulting in minimum weight with a maximal global volume change. Previous deployable tensegrity structures have been developed that demonstrate self-deploying behavior, but only at small scale. Prototypes that use commonly known three and four-strut geometries were built that use low-pressure inflatable struts, developed to maintain their internal air pressure, resist strut deformation that can occur during deployment, and resist buckling that results from loading the structure. The prototypes presented here precede a large-scale pavilion to be exhibited at the 2019 Form and Force Expo in Barcelona. This paper presents several development prototypes, design and analytical strategies for the inflatable compression struts, load-testing results, as well as drawings of the proposed exhibition structure.

Foldable structures currently receive increasing attention in mechanical engineering and architecture. However, due to the complexity of the pattern and of the deployment mechanics, the kinematics and structural behavior of these models result complex to investigate. The topic is tackled in this paper, which is focused on two-dimensional rigid foldable plates based on origami tessellation. The Waterbomb base geometry – on which more complex origami models are based – is here investigated as a particularly interesting case study to catch the design and deployment mechanisms. The design solutions pursued in this paper are based on a detailed analysis of the kinematics and the mechanics of the deployment. This investigation includes the assessment of the forces applied to the control points of the structure to obtain the deployment and of the corresponding mechanical power expended. The geometric control of the unfolding and the evaluation of the kinematics and mechanical behavior are carried out through parametric modeling tools, thus obtaining an efficient design integration between geometry, kinematics and structural response of rigid foldable plates. The structural model has been developed implementing algorithms with the parametric design software Grasshopper and its add-on GeometryGym, which enables to add structural information to the geometry, to export the model into finite element analysis software and to get detailed information about the stress and strain fields as well as the deployment forces.

Rigid-foldable systems inspired by Origami enable the development of complex structures only governed by few variables. A method to design deployable structures considering geometrical and structural issues is described. Drawing of the geometry and analysis of the structural behaviour are integrated in a continuous process to find the best configuration of deployment. Parametric design is proposed as the ideal powerful method for modelling Origami structures, applicable in both geometrical and analysis processes. The parametric software Grasshopper has been applied to draw the geometry and to control the leading configuration parameters, while FEA software has been used to study the structural behaviour. To connect parametric and structural analysis software, GeometryGym (Grasshopper plug-in) has been investigated as particularly interesting to define the structural features. The purpose of this paper is to provide a guideline to design Origami structures using parametric methodology and to describe drawing and structural analysis steps applied to two specific cases: Waterbomb and Yoshimura Origami.

Origami is a Japanese art of folding paper. Recently it has started to be used in
aerospace applications such as deployable masts, satellite antennas, and in architectural
applications such as emergency shelters, temporary shelters, portable exhibition stands.
Deployable plate structures based origami art are attractive to both architects and
engineers because of their structural and spatial qualities. They have special geometries
according to the rigid origami patterns. The Miura-Ori is a rigid origami pattern that is
formed from a tessellated arrangement of a single repeated unit consists of four
quadrangle plates. It has fully folded and fully deployed configurations.
This research investigates geometric and mobility aspects of Miura-Ori pattern
with its derivations and explore the possibilities of constructing a deployable plate
structure using the same pattern. The first part of the research investigates geometry of
the Miura patterns. The aim is to generate derivations by changing the input parameters.
Small scale physical models are built to verify the geometric design guidelines.
Miura unit consisted of four plates and four joints is a single degree of freedom
spherical mechanism. The second part of the research is concentrated on mobility
analysis. The aim is to develop a method for removing excessive plates and joints
without changing the mobility. The established equations assist us to determine nth term
of the excessive plates and joints. A Method of Double Arrangement (MoDA) is
developed in order to determine the placement of excessive plates.
Finally, a deployable plate structure based on Miura-Ori pattern is proposed for
an architectural application. However, the plates cause obstruction of the sky, thereby
affecting sunlight and daylight availability inside the building. Thus, some excessive
plates are reduced according to the proposed method. The final form of the structure lets
to get more energy from the sun to provide heating and lighting.
Keyword: rigid origami, Miura-Ori, spherical mechanisms, mobility.

We present a shape memory polymer (SMP) honeycomb with tuneable and shape morphing mechanical characteristics. Kirigami (Origami with cutting allowed) techniques have been used to design and manufacture the honeycomb. The cellular structure described in this work has styrene SMP hinges that create the shape change and the deployment actuation. To create a large volumetric deployment, the Kirigami open honeycomb configuration has been designed by setting an initial three-dimensional re-entrant auxetic (negative Poisson's ratio) configuration, while the final honeycomb shape assume a convex (positive Poisson's ratio) layout. A model was developed to predict the shape change of the structure, and compared to experimental results from a demonstrator honeycomb deployment test.

— Parallel robots have important benefits where speed, lightness and accuracy are concerned. A peculiar type of parallel robots is called vertical Cable Direct Driven Robot (CDDR). In this paper we discuss an innovative type of planar parallel 2-link, 2-d.o.f., robot which is conceptually similar to CDDRs; in place of using cables, this robot uses Storable Tubular Extendible Member (STEM) actuators, one of which is also capable to actively rotate. STEMs are lightweight mechanisms used mainly in the space industry. We devise a complete model for the behavior of the robot. The kinematics of robot is defined analytically, whereas the structural model is based on numerical and empirical considerations as well. A working prototype of a STEM actuator is presented. The robot is evaluated via the analysis of force polytopes inside the workspace envelope. This allows us to define some useful indexes: maximum force, maximum admissible weight, out-of-plane stiffness. Results show that the robot outperforms Cable Direct Driven Robots (CDDRs). The robot's workspace reaches above the links anchor points and the system can eliminate configuration singularities. Out-of-plane stiffness is indeed computed to be within an acceptable range.

Price thinks, as the physicians, that we are able to build the fourth dimension introducing the factor time. In the writings called “Time and Timing” Price tries to explain the differences between both of them. Time as a design tool is the one that introduce the fourth dimension to the architectural project. He understands Timing as a planning factor and it is an objective one, it is a temporal gap where the projects are running on.  We can understand the term Time, introduce by Cedric Price, at least in two ways:
1- Time as a lineal value that runs constantly between two points; A and B. Time as an absolute factor in all research processes that develop in time intervals.
2- Time as a coordinate that build the fourth dimension with the others three spatial ones.
“Price understands architecture like time events more than object in the space”. If we said that a building must attend the human being, and this one change with the time, then this building shall change too, it could not be static. For the mathematician the fourth dimension will be represent by the hypercube, that is a cube offset in time, ergo, each instant of time by which moved but all of them together.
The fourth dimensional space helped inspire many artists in the first half of the twentieth century. Dalí used the idea of a higher-dimensional mathematics in his painting called “Corpus Hipercubus” but in architecture too. “Vidriera Hipercubica” is the name given by Dali to the project that he commissioned to the architect Emilio Pérez Piñero. In this project we will be able to find the time as a design tool what allows us to interpret the fourth dimension in architecture.
In the project proposed by Cedric Price, called Snake, it could be found several conceptual and methodological similarities to the Vidriera Hipercúbica made by Pérez Piñero. Both of them are proposals, where the concepts space, time, velocity, change and transformation appear and they help us to understand the idea of the fourth dimension in architecture. In the two projects we can ensure that both space and time are in moving, they are changing. Mobility as a design tool that will be introducing in the first part of the planning and allows us to plan the artifact, incorporating the concept of Time through mobility and spatial changes.

This study describes the main regularities for the construction of deployable metal shells of a cylindrical type. The comparative analysis of the efficiency of compact folding methods of thin metal shells of cylindrical and conical types, capable of maintaining the initial load-carrying capacity after unfolding without applying the additional strengthening methods, is presented. The range of possible parameters of long-length structures, constructed on the basis of rigid deployable pressurized shells, is characterized. The paper gives the qualitative and quantitative evaluation of basic functional characteristics of folding inflatable metal structures of cylindrical and conical types under the action of a complex of characteristic external loads, close to the maximum allowable ones. The result of experimental operability confirmation of the proposed structures' configurations is presented.

A deployment solution for a parabolic sail structure for solar photon thrusters (SPTs) is presented. SPTs decouple the function of collection and reflection of light, achieving many advantages over flat solar sails. Although recent and increasingly realistic studies have concluded SPTs an unattractive option, the motivation behind this work is to progress the novel SPT concepts by resolving two problems identified: presenting a feasible solution for deployment and maintaining tight control over the collector shape; and addressing the space durability of carbon-fibre reinforced epoxy-resin composites for long duration solar sailing missions. Laterally curved bistable reeled composites were manufactured in such a way that their beneficial structural properties and bistable behaviour have been complimented with improved environmental resistance. This was achieved by implementing a cycloaliphatic based coating system reinforced with silicon nano-additive. The effect of curvature and additive on the natural frequency were investigated. In addition, response to vacuum outgassing, UV resistance, surface degradation due to atmospheric oxygen and thermal stability were investigated and improved.

The research project presented in this paper aims to extend the repertoire of architectural design and construction. To achieve this purpose, research-through-design methods are used to match a commonly desired target geometry with a realistic and efficient materialisation strategy. The proposed approach has been tested through construction of practical prototypes that eventuated in a full-scale structure that performed well in a variety of outdoor conditions. The outcome of this work is a workflow for semi-automated skinning of complex graphs such as trusses or space frames. The project tests this workflow through an application to a topologically complex L-system. The L-system graph is parametrically skinned with a continuous, adjustable envelope. The outcomes of this skinning are materialised in fabric to produce a twelve-metrelong, wind-supported, airborne inflatable structure. This workflow is a novel extension of existing approaches to skinning and fabrication of structures based on complex graphs because it allows a hitherto unavailable, fabrication-ready geometric definition of joints between cylindrical and conical tubes of varying diameters. It is significant as a reusable approach to the geometric construction of such joints in a variety of materials and across multiple scales. Furthermore, it is interesting as an innovative prototype of possible wind-supported architectural structures.

Tensegrity structure displayed at the entry of Palazzo Mora, in the heart of Venice, in the context of  the 2018 Biennale Architettura. The structure is  based on innovative patented  research in the USA and Europe (my own patents), and its form has been produced using algorithmic design methods. The particularity  of this structure  lies in the fact that it combines in a unique manner features that arise from the intersection of art, technology, architecture and mathematics.  At Palazzo Mora, that has over 300,000 visitors a year.  have been exhibited projects of top universities and  renowned architects.

Origami folding structures can find significant applications in the general area of building design, as they can be lightweight and deployable. An inherent property of folded surfaces, which is related to the degrees of freedom of each origami crease pattern, is form flexibility. Therefore, when building-scale applications are considered, in many instances, the folded surfaces, in order to become stiff and load-bearing, need to be constrained. A study of different types of deployable structures has led to the observation that in planar scissor linkages, hinges and pivots follow the same deployment path in space, as sets of vertices in certain origami structures. Due to the similarities in their kinematic behavior, selected origami patterns and scissor linkages can function as effective kinematic pairs, leading to structures able to transform in a controlled manner through a wide range of possible spatial configurations. A few examples of combining these two types of structures alrea...

A new design for increased power extraction for NanoSatellites is proposed, which is used for KufaSat. This
proposed design contains four expandable panels with additional sixteen solar cells, two solar cells on each side of panel.
The proposed design with additional panels and how these additional panels are assembled to the body of KufaSat and how
they are deployed after the launching are presented. Comparison between original design and proposed design in addition
to discussion the increasing in power production and charge current are included.

This paper initially investigates the previous works on foldable structures. Subsequently, generation and geometric (architectural) design of compatible foldable structures with scissor-like elements is formulated for various shapes of barrels with no geometric limitations (free forms) for the purpose of configuration processing. Special cases for configuration processing based on given formulation are studied to obtain different geometries. For example, the division of the sum of the internal angles of duplets leads to different geometries. The method employed for this division could be equal between duplets, according to arithmetic or geometric progression, or using algebraic equations. These methods are used to divide the sum of internal angles and radius of curvature; Corresponding geometries are then created and compared. The method to generate a geometry imposed by architectural requirements is also proposed in this work. Using such ordering, one can create and model free form...

A tensegrity structure is a special kind of system composed of three or more bars and strings, where any external load is distributed exclusively as axial forces along its members. Each individual unit is made of compressive and tensile elements, and presents tensegrity properties such as equilibrium. With only two geometric parameters (radius r and height l0) and the number of bars p, the nodes matrix N can be generated and the model built. Following steps guide through the creation of the connectivity matrices CS and CB. With the aid of the software Matlab, the internal force density method is used to confirm the equilibrium of the unit cell and suggest modifications. Finally, a three-bar tensegrity structure is built to confirm the results.

This project is aiming to explain through the design process what the role of pavil¬ion in Architecture is. It is developed to analyze the use and the characteristics of the pavilions by pointing out their sin¬gularity in architecture within an urban term.
The project is divided into two parts, the first part is focusing in the urban view of Limassol and aiming to challenge the shortage of Flexible and informal public sports facilities in the city.
The second and part is the use of pavilion in the city and how can a series of fully deployable/adaptable structures can adapt and acts as the solution of forming

An investigation into the bistability of positively curved laminated composite slit tubes is presented, establishing a natural extension in this area that has previously been focused on straight tubes. Curved slit tubes are modeled as the surface segments of a torus. The design space is explored through a parametric study to investigate the effect on the second stable state, representing a small coil. This includes the effects of longitudinal curvature, cross-section subtending angles, nonuniform transverse curvature, and spatially varying laminate properties. The second equilibrium state is determined through strain energy minimization using the Rayleigh–Ritz method. To verify the model, samples are manufactured from glass-fiber braid and polypropylene resin. This investigation finds 1) the initial curvature along the length of the tube has little effect on coil radius, however, the coil has a distinct barrel shape; 2) highly enclosed and 3) highly curved cross-sections result in higher edge strains of the second equilibrium, enabling identification of practical bistable tubes; and 4) conversely, the greater the initial curvature along the length of the tube, the lower the second equilibrium strain.


Read More: https://arc.aiaa.org/doi/10.2514/1.J056411

In continuation of our previous research (Hussein, et al., 2017), this paper examines the kinetic transformable spatial-bar structures that can alter their forms from any free-form geometry to another, which can be named as Free-form transformable structures (FFTS). Since 1994, some researchers have proposed FFTS for many applications such as controlling solar gain, providing interactive kinetic forms, and control the users' movement within architectural/urban spaces. This research includes a comparative analysis and a critical review of eight FFTS precedents, which revealed some design and technical considerations, issues, and design and evaluation challenges due to the FFTS ability to deliver infinite unpredictable form variations. Additionally, this research presents our novel algorithmic framework to design and evaluate the infinite form variations of FFTS and an actuated prototype that achieved the required movement. The findings of this study revealed some significant desi...

19th century engravings of the Azoguejo Square in Segovia (Spain) offer repeated scenes of flying merchants and street markets at that time. Within all these repeated and copied romantic scenes, some elements are a constant in all of them: The Aqueduct and its surrounding (changing and re-interpreted in many cases depending on the artist), Architecture and one other element: the merchant's tent, a deployable self-supported textile solution made out of a stretched fabric braced to a self-supported central wooden tripod structure. The research will try to understand its built environment, the permanent city in which these transient elements move from town to town. The paper will also try to shed some light on these specific prototypes as a specific traditional and non-scientific wisdom of experimentation developed by peasants and merchants, besides being a refined small-scale structural solution. On a third part, we will try to bridge the typological gap between traditional light and deployable structures from the traditional Arab Khaimah (tent), linking it with other small-scale devices like the parasol or the umbrella, imported from China.
The paper will try to prove how this typology cannot be considered just as a mere temporary element of a larger city structure (street market), because its consistency and adaptability is what actually makes it a primary element of the urban tissue. The tent is an element which occupied the city during centuries, adapting its function and organic footprint to an ever-changing urban landscape. It is this kind of elements the ones that remain beyond the built form, the ones that create the city trough memories, trading and social interaction. They are, at the end of the day, the most permanent part of the city: the real place makers.

The bistability of a toroidal slit tube is modeled using the Rayleigh-Ritz method. Approximate explicit expressions for the original stable deployed geometry, and the deformed stowed geometry are used to derive forms for the bending and stretching strain energy. The surface of a torus has varying Gaussian curvature, requiring a new approach to the modeling and analysis of the stable configurations. A comparative study with established straight-BRC models was conducted from which the doubly curved-BRC model presented here predicts second stable state coil radii with 96.25% agreement.

This paper presents a novel type of deployable grasping manipulator (DGM), the fingers of which are constructed of serially connected metamorphic mechanism modules (MMMs), which are the key components for this type of robotic manipulator. A systematic approach for the synthesis of the MMMs is proposed. The MMM consists of one grasping submechanism and two auxiliary sub-mechanisms, and the metamorphic principle is applied to the design of the grasping sub-mechanism to give it both deployment and grasping mobility. The design of the MMMs becomes a type of synthesis problem for the auxiliary submechanisms based on the given metamorphic mobility of the grasping sub-mechanism. The auxiliary mechanisms are exhaustively synthesised based on the typical screw theory. Computer-aided design (CAD) models and physical prototypes are used to show the feasibility of the proposed mechanisms.

La atención a la evacuación del agua de lluvia y a la protección de la estructura ante los agentes meteorológicos ha dado lugar a un conjunto de propuestas de estructuras desplegables de aspas sobre planta rectangular en las que estas estructuras definen limas y faldones de pendiente suficiente. El trabajo parte de la resolución del trazado de estructuras desplegables de aspas planas simétricas y base cuadrangular con directriz quebrada, garantizándose el correcto funcionamiento cinemático mediante la construcción de modelos. Se estudian desplegables con directrices poligonales, curvas compuestas y también combinaciones de curvas y rectas. Se repasan los problemas de estabilización de la solución en el estado desplegado, incorporando la cobertura textil y cables de arriostramiento. Finalmente se desarrollan y analizan geométrica y cinemáticamente una serie de propuestas con superficies de intradós y extradós diferentes y otro grupo de ellas en las que los sentidos de despliegue no s...

Origami folding structures can find significant applications in the general area of building design, as they can be lightweight and deployable. An inherent property of folded surfaces, which is related to the degrees of freedom of each origami crease pattern, is form flexibility. Therefore, when building-scale applications are considered, in many instances, the folded surfaces, in order to become stiff and load-bearing, need to be constrained. A study of different types of deployable structures has led to the observation that in planar scissor linkages, hinges and pivots follow the same deployment path in space, as sets of vertices in certain origami structures. Due to the similarities in their kinematic behavior, selected origami patterns and scissor linkages can function as effective kinematic pairs, leading to structures able to transform in a controlled manner through a wide range of possible spatial configurations. A few examples of combining these two types of structures alrea...

The vibration characteristics of cantilevered straight and curved carbon/epoxy bistable reeled composites (BRCs) have been investigated. The tube length, cross-section radius, subtending angle, longitudinal curvature and number of plies-design parameters were investigated for their effects on the vibration modes. The boom length affects the frequency the most, which is found to be inversely proportional to the square of boom length, in addition to ABAQUS simulation results showing that frequency is proportional to curvature. Short, three-ply carbon/epoxy samples were manufactured and tested. A regime change from short (48.5cm) to slender (≈150cm) tubes was observed, signified by curved tubes exhibiting higher vibration modes in a particular plane than the straight ones in simulation-highlighting the scalability of curved BRC applications. Recommendations for the upcoming CleanSpace One, EPFL space mission which uses curved tubes for its capture mechanism, are discussed. Dynamic stability analysis was performed by simulating increasing rotary accelerations, causing the cantilevered BRCs attached to a spacecraft to rotate. A failure point derived from the Budiansky-Hutchinson criterion was developed to determine the maximum rotation acceleration-the critical value by which the tube loses stability.

When the existing literature on the research of scissor structures is thoroughly investigated, it is seen that different researchers use different terminologies and classifications especially for the definition of the primary units and the motion type. Some of the studies define the whole geometry based on the geometric properties of the primary scissor units and the unit lines while some other studies define it according to the loops. All these studies use different names for similar elements. This article aims to review the literature on the classification and terminology of scissor structures and represent the state of art on the studies. Tables are represented showing all approaches in the literature. In addition, the article criticizes the missing points of each terminology and definition, and proposes some new terminology. In order to arrive at this aim, different definitions of the primary scissor units and motion types used in key studies in the literature are investigated thoroughly. With several examples, it is demonstrated that naming the scissor units according to the resulting motion type might be misleading and it is better to specify the motion type for the whole structure. A classification for transformation of planar curves is presented.

La atención a la evacuación del agua de lluvia y a la protección de la estructura ante los agentes meteorológicos ha dado lugar a un conjunto de propuestas de estructuras desplegables de aspas sobre planta rectangular en las que estas estruc-turas definen limas y faldones de pendiente suficiente. El trabajo parte de la resolución del trazado de estructuras desple-gables de aspas planas simétricas y base cuadrangular con directriz quebrada, garantizándose el correcto funcionamiento cinemático mediante la construcción de modelos. Se estudian desplegables con directrices poligonales, curvas compuestas y también combinaciones de curvas y rectas. Se repasan los problemas de estabilización de la solución en el estado des-plegado, incorporando la cobertura textil y cables de arriostramiento. Finalmente se desarrollan y analizan geométrica y cinemáticamente una serie de propuestas con superficies de intradós y extradós diferentes y otro grupo de ellas en las que los sentidos de despliegue n...