Deployable structure

A deployable structure is a structure that can change shape so as to significantly change its size.[1][2]

Examples of deployable structures are umbrellas, some tensegrity structures, bistable structures, some Origami shapes and scissor-like structures. Deployable structures are also used on spacecraft for deploying solar panels and solar sails.

Space-based deployable structures can be categorized into three primary classes: the first is the articulated structure class wherein rigid members contain sliding contact joints or are folded at hinge points and pivot to deploy, often locking into place. The second class consists of on-orbit assembly where a device is fabricated and/or mechanically joined in space to form the structure. The final class is high strain structures (often composed of High strain composites) wherein the device is dramatically flexed from one configuration to another during deployment.

Field control tower P1220950
A field deployable control tower

Gallery

Scissor Tower

Scissor-type structure

Scissor Tower3

Multiple scissor-type structure

Deployable Structure1

Outward folding deployable ring structure

Deployable Structure2

Inward folding deployable ring structure

Nustar mast deployed v2

NuSTAR mast in the stowed configuration.

Nustar mast deployed

NuSTAR mast deployed.

See also

References

  1. ^ S. Pellegrino (Ed.), Deployable Structures, CISM International Center for Mechanical Sciences, Springer, 2002
  2. ^ http://www-civ.eng.cam.ac.uk/dsl/

External links

Developable mechanism

Developable mechanisms are a special class of mechanisms that can be placed on developable surfaces.

Glossary of structural engineering

Most of the terms listed in Wikipedia glossaries are already defined and explained within Wikipedia itself. However, glossaries like this one are useful for looking up, comparing and reviewing large numbers of terms together. You can help enhance this page by adding new terms or writing definitions for existing ones.

This glossary of structural engineering terms pertains specifically to structural engineering and its sub-disciplines. Please see glossary of engineering for a broad overview of the major concepts of engineering.

High strain composite structure

High Strain Composite Structures (HSC Structures) are a class of composite material structures designed to perform in a high deformation setting. High strain composite structures transition from one shape to another upon the application of external forces. A single HSC Structure component is designed to transition between at least two, but often more, dramatically different shapes. At least one of the shapes is designed to function as a structure which can support external loads.

High strain composite structures usually consist of fiber-reinforced polymers (FRP), which are designed to undergo relatively high material strain levels under the course of normal operating conditions in comparison to most FRP structural applications. FRP materials are anisotropic and highly tailor-able which allows for unique effects upon deformation. As a result, many HSC Structures are configured to possess one or more stable states (shapes at which the structure will remain without external constraints) which are tuned for a particular application. HSC Structures with multiple stable states can also be classified as bi-stable structures.

HSC Structures are most often used in applications where low weight structures are desired that can also be stowed in a small volume. Flexible composite structures are used within the aerospace industry for deployable mechanisms such antennas or solar arrays on spacecraft. Other applications focus on materials or structures in which multiple stable configurations are required.

Hoberman mechanism

A Hoberman mechanism is a deployable mechanism that allows circumferential actuation to generate radial motion. The kinematic theory behind the Hoberman mechanism has found application in creating deployable structures for space. The mechanism has one degree of freedom. However, in case of singularity it can gain extra degrees of freedom.

Jean-Loup Chrétien

Jean-Loup Jacques Marie Chrétien (born 20 August 1938) is a French retired Général de Brigade (brigadier general) in the Armée de l'Air (French air force), and a former CNES spationaut. He flew on two Franco-Soviet space missions and a NASA Space Shuttle mission. Chrétien was the first Frenchman and the first western European in space.

Linkage (mechanical)

A mechanical linkage is an assembly of bodies connected to manage forces and movement. The movement of a body, or link, is studied using geometry so the link is considered to be rigid. The connections between links are modeled as providing ideal movement, pure rotation or sliding for example, and are called joints. A linkage modeled as a network of rigid links and ideal joints is called a kinematic chain.

Linkages may be constructed from open chains, closed chains, or a combination of open and closed chains. Each link in a chain is connected by a joint to one or more other links. Thus, a kinematic chain can be modeled as a graph in which the links are paths and the joints are vertices, which is called a linkage graph.

The movement of an ideal joint is generally associated with a subgroup of the group of Euclidean displacements. The number of parameters in the subgroup is called the degrees of freedom (DOF) of the joint.

Mechanical linkages are usually designed to transform a given input force and movement into a desired output force and movement. The ratio of the output force to the input force is known as the mechanical advantage of the linkage, while the ratio of the input speed to the output speed is known as the speed ratio. The speed ratio and mechanical advantage are defined so they yield the same number in an ideal linkage.

A kinematic chain, in which one link is fixed or stationary, is called a mechanism, and a linkage designed to be stationary is called a structure.

Mir EO-4

Mir EO-4 (also called Principal Expedition 4) was the fourth long-duration expedition to the Soviet space station Mir. The expedition began in November 1988, when crew members Commander Aleksandr Volkov and Flight Engineer Sergei Krikalev arrived at the station via the spacecraft Soyuz TM-7. The third crew member of EO-4, Valeri Polyakov, was already aboard Mir, having arrived in August 1988 part way through the previous expedition, Mir EO-3.

The expedition lasted for five months, and at its conclusion Mir was left unmanned until the launch of Mir EO-5 in September 1989. This ended a continuous habitation of the space station which began in February 1987, with the arrival of the crew of Mir EO-2.

Robotics Design Inc

Robotics Design Inc. is a company that designs and builds modular robots, founded and incorporated in Montreal, Quebec, Canada in 1997. The company produces mobile robots, robotic manipulators and manual arms as well as custom solutions using modular robotic technology. The company developed the BIXI bike dock, a public bike system, and the ADC (Automatic Deployable Container), a deployable structure container for quick deployment of housing, hospitals and other buildings.

Soyuz TM-7

Soyuz TM-7 was the seventh manned spacecraft to dock with the Soviet Space Station Mir. Its launch in November 1988 represented the start of the fourth long duration expedition, Mir EO-4, as it carried two more Soviet cosmonauts, Sergei Krikalyov and Alexander Volkov, to the station. They would join the third crew member of EO-4, cosmonaut/physician Valeri Polyakov, who was on Mir for the second half of EO-3. Also launched by Soyuz TM-7 was French astronaut Jean-Loup Chrétien, who would take part in the 24-day French mission known as Mir Aragatz. The spacecraft Soyuz TM-7 remained docked to Mir for the duration of EO-4. At the end of EO-4 in April 1989, due to delays in the launch schedule, Mir was left unmanned, and all three EO-4 crew members were transported back to Earth.

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