Lightweight, low-volume, and spatially deployable batten restrass

Abstract

The systems and methods described herein include a collapsible and deployable truss structure that defines a reduced volume for compact storage.

Description

[Technical Field]

[0001] Priority This application claims priority to U.S. Provisional Patent Application No. 63 / 114,809, filed November 17, 2020, which is incorporated herein by reference in its entirety. [Background technology]

[0002] A truss is an assembly of members, such as beams, connected by nodes to form a rigid structure. In engineering, a truss is a structure with force members, where the members are arranged so that the assembly as a whole behaves as a single body.

[0003] 1A-1C illustrate an exemplary conventional deployable truss system in which multiple members are rigid and connected to each other at nodes. Conventional truss systems have been patented, such as U.S. Pat. No. 5,680,145, which is incorporated herein by reference in its entirety. As shown, such a truss includes multiple nodes 102 from which force members 102 extend outward. Each node has a longeron force member extending longitudinally along the deployment structure to another node and a batten force member extending laterally across the deployment structure, perpendicular to the longeron force members. The force members 102 are rigid, forming a single, defined, rigid structure. A deployment cable 106 is used to deploy the truss. The cable 106 is flexible. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 5,680,145 Summary of the Invention [Problem to be solved by the invention]

[0005] As shown, all truss members are joined at nodes with multiple or three or more rigid members together, so the achievable size of the collapsed system is limited by the height of the rigid structure. [Means for solving the problem]

[0006] The batten-less trusses described herein provide a foldable structure that reduces the storage volume of the deployable structure. Exemplary embodiments may include a structure for use as a perimeter truss for a reflector antenna and / or a solar concentrator.

[0007] Exemplary embodiments include trusses, which comprise an assembly of members such as longerons connected by nodes that form a rigid structure when deployed. Exemplary embodiments of batten-rest trusses may include foldable longerons between the nodes. The longerons may be hinged, comprise shape memory composites, or comprise other deformable materials. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 illustrates an exemplary prior art truss system. [Figure 1B] 1 illustrates an exemplary prior art truss system. [Figure 1C] 1 illustrates an exemplary prior art truss system. [Figure 2A] 10 illustrates an exemplary collapsed to extended deployment sequence of an exemplary batten restraint, according to embodiments described herein. [Figure 2B] 10 illustrates an exemplary collapsed to extended deployment sequence of an exemplary batten restraint, according to embodiments described herein. [Figure 2C] 10 illustrates an exemplary collapsed to extended deployment sequence of an exemplary batten restraint, according to embodiments described herein. [Figure 3A]1 illustrates an exemplary deployment system for use with a batten restraint system, according to embodiments described herein. [Figure 3B] 1 illustrates an exemplary deployment system for use with a batten restraint system, according to embodiments described herein. [Figure 4] 1 illustrates an exemplary support structure comprising an exemplary embodiment of a batten restrust, according to embodiments described herein. [Figure 5A] 1 illustrates an exemplary application using a support structure comprising an exemplary embodiment of a batten restrust according to embodiments described herein. [Figure 5B] 1 illustrates an exemplary application using a support structure comprising an exemplary embodiment of a batten restrust according to embodiments described herein. [Figure 6] 5A-5B illustrate exploded views of exemplary components of the application of FIGS. [Figure 7A] 10 shows an exemplary comparison of reduced storage volume achievable with exemplary embodiments of a batten restrauss according to embodiments described herein. [Figure 7B] 10 shows an exemplary comparison of reduced storage volume achievable with exemplary embodiments of a batten restrauss according to embodiments described herein. [Figure 7C] 10 shows an exemplary comparison of reduced storage volume achievable with exemplary embodiments of a batten restrauss according to embodiments described herein. [Figure 7D] 10 shows an exemplary comparison of reduced storage volume achievable with exemplary embodiments of a batten restrauss according to embodiments described herein. [Figure 7E] 10 shows an exemplary comparison of reduced storage volume achievable with exemplary embodiments of a batten restrauss according to embodiments described herein. [Figure 8A] 10 shows an exemplary comparison of reduced storage volume achievable with exemplary embodiments of a batten restrauss according to embodiments described herein. [Figure 8B]10 shows an exemplary comparison of reduced storage volume achievable with exemplary embodiments of a batten restrauss according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following detailed description illustrates the principles of the present invention by way of example, not by way of limitation. The description clearly enables one skilled in the art to make and use the invention and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently contemplated to be the best mode of carrying out the invention. It should be understood that the drawings are diagrams and schematic representations of exemplary embodiments of the invention, are not limiting of the invention, and are not necessarily drawn to scale.

[0010] Exemplary embodiments may use deformable members as supports and deployment structures for use in truss systems.

[0011] While embodiments of the present invention may be described herein with reference to a particular support structure, it should be understood that embodiments of the present invention are not so limited but are further applicable to different configurations. Exemplary embodiments further disclosed herein include different combinations of deformable options for the support, and any combination of such support structures or alternative deformable options is contemplated for use herein. Exemplary embodiments may include alternative features, such as easily peelable surfaces, removable shrink or containment materials or cords, envelopes, one or more antenna shapes, one or more sleeves or envelopes, one or more support infrastructures, hubs, one or more inflation mechanisms, housings, actuators, controllers, cables, pulleys, and the like. Any feature, component, configuration, and / or attribute described with respect to any one example may be used in combination with any other example. Thus, any step, feature, component, configuration, and / or attribute may be used in any combination and remain within the scope of the present disclosure. Features may be removed, added, duplicated, merged, subdivided, or otherwise recombined and remain within the scope of the present disclosure. The exemplary embodiments described herein are provided for purposes of example only, and thus any antenna, collector, support structure, or other configuration may be used with or without any of the components described herein.

[0012] 2A-2C illustrate an exemplary collapsed-to-extended deployment sequence for an exemplary batten truss, according to embodiments described herein. FIG. 2A illustrates an exemplary configuration with the longerons fully folded. The diagonals are shown vertically. The illustrated diagonals in this example are not telescopic. FIG. 2B illustrates an exemplary configuration with the longerons partially folded. FIG. 2C illustrates an exemplary configuration with the truss sections fully deployed. The truss is configured as a Warren truss.

[0013] FIG. 2A shows how a battenless perimeter truss is stowed in an exemplary configuration. As shown, the height of the folded / stowed configuration can be approximately the length of the diagonal members. By using telescoping diagonals, the stowed height can be made shorter. The configuration of FIG. 2A can be compared to the stowed height of the exemplary prior art system of FIG. 1A. The difference in stowed height is more clearly shown in FIGS. 8A-8B.

[0014] The exemplary truss 200 is composed of structural members 202 joined by nodes 204. The structural members may include diagonals 208 and longerons 206. The longerons are configured to extend longitudinally along the length of the truss in the deployed configuration according to embodiments described herein. The diagonals are configured to extend across and along the truss in the deployed configuration or at an angle to the longerons in the deployed configuration according to embodiments described herein. The diagonals of the truss are configured such that they are not perpendicular to the longerons in the deployed configuration.

[0015] In exemplary embodiments, the diagonal members may be rigid members that are not configured to substantially deform during storage or deployment. The longerons may comprise deformable members configured to deform or have a different shape from a stored configuration to a deployed configuration. As used herein, a deformable member may comprise any configuration that deforms as described herein. For example, the deformable member may be soft and flexible under the application of an external force.

[0016] The terms rigidity and flexibility are understood to be relative terms as used herein. Thus, it is understood that a rigid structure may still have some bending when subjected to sufficient external force, but such absolute rigidity is not required. Instead, those skilled in the art will understand that a rigid structure is intended to generally maintain its shape during normal operation and for its intended purpose. A flexible structure is considered to deform along its length. Deformation may be by application of sufficient external force without separating or destroying the structure, thereby allowing the structure to reconfigure to its original configuration. A deformable structure is considered to deform at a point or along its length. Thus, a deformable structure may comprise a joint, a hinge, a living hinge, a flexible member, or a combination thereof.

[0017] Exemplary embodiments described herein include a deformable structure that can still provide structural rigidity when the structure is fully deployed. For example, the deformable structure may be configured to deform under lateral or shear forces applied to the structure. A lateral force can be applied via the system architecture to deform the deformable structure and position the structure in the stowed configuration. The deformable structure may be configured to maintain its shape or to maintain rigidity under compressive or longitudinal forces applied to the structure. The rigidity of the structure may be maintained during normal use of the structure in its deployed configuration. Thus, the deformable structure may be both deformable and rigid depending on the direction of the applied force.

[0018] Exemplary embodiments of the deformable structure may comprise any combination of configurations to achieve the deformable configurations described herein.

[0019] For example, exemplary embodiments of the deformable structure may comprise shape memory composites. These composites are flexible and allow dynamic deformation under the application of an external force. Shape memory composites may also be frozen or held in a deformed configuration, such as by a temperature transition. Shape memory composites may be configured to return to a memorized configuration. The memorized configuration may be through passive or active transition. Shape memory composites may passively return to a memorized configuration for use in a deployed configuration by returning to the memorized configuration after the external force that caused the deformation is removed. Shape memory composites may actively return to a memorized configuration when a transition condition is met, such as a change in temperature or the application of an electric current.

[0020] Exemplary embodiments of the deformable structures described herein may comprise elastomeric shape memory carbon composites. Exemplary embodiments may include other high-strain materials. Exemplary embodiments of shape memory composites may be used as structural elements, such as the longeron members of the trusses described herein. The longerons may include structural fibers impregnated with elastomeric resins or shape memory metals, such as Nitinol. The structural fibers may be made of carbon, fiberglass, aramid (e.g., Kevlar®), Vectran®, or combinations thereof. The longerons may be wrapped in very thin films coated with SiO2 and / or Al2O3 to protect against atomic oxygen. The coating may contain approximately 50 Å of SiO2 or 35 Å of Al2O3. These coatings at these thicknesses have been shown to protect against degradation by atomic oxygen present at lower LEO altitudes.

[0021] Exemplary embodiments of the deformable structures described herein may comprise thermally stable, shape-trainable, high-strain, superelastic shape memory alloy materials. Exemplary embodiments of the shape memory alloy materials may be made of Nitinol or other alloys of Ni-Ti composites. Embodiments may include ternary alloy types of Ni-Ti, with the addition of a third element for more stable performance in shape setting, shape precision, and lifespan in space environments. The properties of the shape memory composite alloy can be tailored by controlling the relative amounts of the alloying elements.

[0022] Exemplary embodiments of the deformable structures described herein may include rigid members with flexible or deformable portions. For example, the deformable structures may include rigid members joined by hinges. Exemplary hinges may be creased by sockets, rods, flexible materials, or other known hinge structures.

[0023] Deformation may be dynamic or structured. Dynamic deformation may allow deformation based on an applied force to deform the structure. Dynamic deformation may allow deformation of a member along its length in response to an applied force. Thus, a member may deform into different shapes or configurations under different applied forces. Structured deformation may allow deformation in a known or predetermined manner. An example of a structured deformation is a hinge.

[0024] As shown in Figures 2B-2C, exemplary embodiments of truss structures described herein include multiple structural members connected to one another by multiple nodes. The connections between the structural members and the nodes allow the structural members connected at the nodes to be repositioned relative to one another to transition between deployed and stowed configurations, and vice versa. As shown, each node includes at least two structural members: at least one diagonal structural member and at least one longeron structural member. An interior node may include at least four structural members: at least two diagonal members and at least two longeron members connected to the same node. Thus, multiple nodes may include at least four structural members extending therefrom.

[0025] In an exemplary embodiment, the diagonal structural members are rigid. The diagonal structural members may be rigid in the deployed configuration, the stowed configuration, and in a transition state between the stowed and deployed configurations.

[0026] In exemplary embodiments, the longeron structural members are deformable. The longeron structural members may be deformable according to any configuration or embodiment described herein. The longeron structural members may be deformable in transitions from the stowed and deployed configurations as described herein. The longeron structural members may be rigid in the deployed configuration under expected and / or normal operating forces, such as compressive forces applied to the longeron.

[0027] 3A-3B illustrate an exemplary deployment system for use in a batten restraint system, according to embodiments described herein. Figures 3A-3B illustrate an exemplary structure in the form of a pantograph truss.

[0028] The example embodiments described herein may include a deployment system that may assist in the transition of the truss from a folded configuration to a deployed configuration or from a deployed configuration to a folded configuration.

[0029] The exemplary embodiment of truss structure 300 comprises a plurality of structural members 302 and nodes 304. The structural members and nodes may comprise structural members 202 or nodes 204 as described with respect to Figures 2A-2C or as described herein. The structural members 302 may comprise deformable structures as described herein. Longerons as shown may be deformable.

[0030] As shown, the longerons comprise a deformable member comprising a shape memory composite. The shape memory composite may be deformable under the application of an external force. The shape memory composite may have a memorized configuration to which it automatically or passively returns after the external force is removed. As shown, the memorized configuration is a linear configuration and the deformed configuration is bent.

[0031] The truss system 300 shown herein also provides a deployment system, which may include a cable 308 and a number of pulleys 310.

[0032] The system may have a deployed configuration as shown in Figure 3A. The cables may be positioned so that they are in neutral tension, or may be positioned so that they are not under tension, so that they do not apply a shear force to the longerons. Because the cables are not applying an external force to the longerons, the longerons maintain their memorized configuration. Thus, the longerons are straight and deployed.

[0033] The system is in a stowed configuration in which the longerons are deformed and the structure is collapsed. Figure 3B illustrates an exemplary transition from the deployed configuration to the stowed configuration. A force is applied to the cable 308, causing the cable to be under tension. The cable is coupled to both sides of the truss, zigzagging between adjacent longitudinal longerons on the same side of the truss and opposing longerons on both sides of the truss. For example, the cable is coupled to a first longeron on a first side of the truss and then to a first opposing longeron on a second side of the truss. The second side of the truss is opposite the first side of the truss. The first longeron may be longitudinally offset from the first opposing longeron. The cable may then be coupled to a second longeron on the first side of the truss. The second longeron may be longitudinally adjacent to the first longeron. The second longeron may be longitudinally offset from the first opposing longeron. The cable may then be coupled to a second opposing longeron. The second opposing longeron may be longitudinally adjacent to the first opposing longeron or longitudinally offset from the second longeron. The cable may repeat n longerons and n opposing longerons in this manner, forming a zigzag between opposing sides of the truss. When a force is applied to the cable, a force is applied to the deformable longeron that deforms the member toward the center of the truss or toward the opposite side of the truss. Thus, the system may be configured to collapse or remain in a stowed configuration by continuously applying tension to the cable. When tension is removed from the cable, the longerons return to the memorized configuration and can deploy to the deployed configuration.

[0034]

[0013] Figure 4 illustrates an exemplary support structure comprising an exemplary embodiment of a Batten rest truss according to embodiments described herein.

[0014] Figure 4 illustrates an exemplary structure in the form of a Warren perimeter truss.

[0035] The exemplary embodiments described herein may be used as lightweight, low-package-volume deployable perimeter truss designs for antennas and concentrators. The exemplary embodiments described herein may include longerons and diagonals. In exemplary embodiments, there are no cross members or batten members. The exemplary embodiments include any combination of the configurations described herein.

[0036] In an exemplary embodiment, the longerons and diagonals can be made of rigid members such as steel, aluminum, or titanium. They can also, or alternatively, be made of materials such as (a) carbon, (b) fiberglass, (c) Kevlar, (d) Vectran, (e) elastomeric shape memory carbon composite (SMCC), (f) Sub-T g (f) a stiffenable composite made from resin-impregnated structural fabric, or (g) a composite of similar materials, or a combination thereof. g The structural fabric for the composite may be (a) carbon, (b) fiberglass, (c) Kevlar®, (d) Vectran®, (e) similar materials, or (f) combinations thereof.

[0037] If the member is made of a shape memory composite (SMCC) structural fabric, the resulting composite can be folded for packaging and, when the restraint is removed, unfold to assume the memorized shape. On the other hand, if the longeron is made of a rigid material such as steel, aluminum, titanium, (a) carbon, (b) fiberglass, (c) Kevlar®, and (d) Vectran® composites, a locking hinge may be present at its midpoint or along its length. The hinge may be used to bend the longeron at its midpoint or at another desired length for storage. If an SMCC composite is used, a hinge is not necessary, as the material tends to bend when a point load is applied perpendicular to its length, and the longeron can be bent at its midpoint or at a desired location. When the SMCC member is unfolded, it can become a compression-tension member.

[0038] Sub-T as described herein g The resin is heated to its glass transition temperature T g The resin may be a polymer or polyurethane resin, which becomes rigid below this temperature.

[0039] Shape memory composites allow the exemplary embodiments described herein to fold under the application of an external force in a non-structural manner. Thus, the folded configuration may be dynamically determined based on the storage compartment or the applied external force. For example, the shape memory composite may be flexible or deformable along its length when a force is applied. However, the shape memory composite returns to a memorized configuration when the force is removed. Thus, exemplary embodiments may include a stored configuration in which the application of an external force holds the deorbiter structure in a stored configuration with a reduced storage volume, and a deployed configuration in which the deorbiter structure is fully deployed with a larger storage volume when the external force is removed. In other words, the memorized or biased configuration may be a deployed configuration in which the deorbiter structure is configured for use as a solar sail or atmospheric deceleration device, or other large-area shape. In exemplary embodiments, the shape memory composite may be flexible in any direction under the application of an external force. In exemplary embodiments, the shape memory composite may be flexible along the length of the member or at multiple locations along the entire length of the member. In an exemplary embodiment, the shape memory composite can return to a memorized configuration, such as a straight, circular, oval, curved, parabolic, spiral, or other predetermined shape, when the external force is removed.

[0040] Exemplary shape memory composite materials include a substrate of one or more of carbon fiber, Vectran®, Kevlar®, fiberglass, fiberglass, plastic, and / or fiber metal. The substrate comprises strands. The strands may be generally aligned along the length of the structure, may include one or more aligned configurations, may be wrapped, spirally arranged, woven, or any combination thereof. The shape memory composite material includes a matrix around and / or between the substrates. The matrix may be silicone, urethane, or epoxy. Exemplary shape memory composite materials are described in commonly owned U.S. Patent Application Publication No. 2016 / 0288453, entitled "Composite Materials." High-strain materials allow for deformation. High-strain materials generally have the ability to strain more than 3% and not enter plastic deformation. In other words, the material may bend more than 3%.

[0041] In an exemplary embodiment, the shape memory composite material has a fiber-to-resin volume fraction ratio that can be controlled to achieve the desired shape memory retention, even after extended storage in a folded / packaged state. An exemplary fiber-to-resin volume fraction ratio is 52-65, i.e., 52%-65% fiber, or 48%-35% matrix or resin. The average fiber-to-matrix ratio is approximately 58%. The fiber may be carbon, Kevlar®, Vectran®, nylon, or other methods described herein, and the resin may be urethane, silicone, or epoxy, or other methods described herein as a matrix.

[0042] 5A-5B illustrate an exemplary application using a support structure comprising an exemplary embodiment of a batten-less truss according to embodiments described herein. FIG. 6 illustrates an exploded view of exemplary components of the application of FIGS. 5A-5B. The application of FIGS. 5A-6 illustrates an exemplary concept of a batten-less spatially deployable antenna. Other applications, such as reflectors, collectors, etc., are also contemplated herein.

[0043] Large-area reflectors in space are commonly used as radio frequency (RF) reflector antennas for communications or radar imaging, as well as solar concentrators for generating solar-powered electricity. Space-deployable reflector antennas or solar concentrators are preferably lightweight and foldable into a volume small enough to fit within a rocket booster fairing. An exemplary embodiment described herein includes a low-weight, low-package volume foldable reflector antenna / concentrator perimeter truss support without battens (transverse members). The exemplary purpose of the perimeter truss in this embodiment is to connect and support the reflector and inverted dome. The reflector and inverted dome, which can mate with the perimeter truss, are net-mesh surfaces made of rigid non-conductive or conductive materials. The reflector dome can be designed to achieve a specific shape, i.e., a surface of revolution, under appropriate tension. The surface of revolution may be any surface of revolution, such as a parabolic, spherical, or a substantial approximation thereof. The inverted dome may be a mirror image of the reflector dome, but need not be as precise as the reflector dome. Between the inverted dome and the reflector dome are tension ties (force elements) that are used to apply stress or tension to the conductive mesh. Thus, the reflector and inverted dome provide anchor points for these tension ties. When properly tensioned, the reflector dome contacts the conductive mesh, conforming it to the reflector dome's shape. The conductive mesh acts as a reflector for electromagnetic energy. In RF applications, the conductive mesh can also be a thin film metallized with a few hundred angstroms of evaporated or sputtered aluminum or silver. In solar concentrator applications, the conductive mesh is replaced with a thin film metallized with a few hundred angstroms of evaporated or sputtered aluminum or silver. Thin films of other materials are also possible. The thin film can be, for example, a polyimide or polyester material.

[0044] As shown in FIGS. 5A-6, an exemplary embodiment of a reflector 500 is provided. The reflector comprises a perimeter truss according to embodiments described herein. The perimeter truss comprises longerons 504 as described herein. A reflective surface 506 is coupled to the perimeter truss 502. Support connections suspend a net perimeter 510 and provide tension to the outer edge 508 of the reflector surface, forming a tension drum 508. The perimeter truss 502 in this embodiment may couple to and support a reflector dome 602 and an inverted dome 604. The reflector dome 602 and the inverted dome 604 may comprise netting, mesh, cable, etc. There may be tension ties 606 (force elements) between the inverted dome 604 and the reflector dome 602 that are used to apply stress or tension to the conductive mesh.

[0045] 7A-8B show an exemplary comparison of the reduced storage volume achievable with an exemplary embodiment of a batten-rest truss according to embodiments described herein. 7A-8B show a comparison of the storage height of an exemplary embodiment of a batten-rest truss described herein and a conventional truss system.

[0046] An advantage / feature of the exemplary embodiment is that the packaged volume of the exemplary spatially deployable antenna can be at least half that of existing similar configurations. Further reduction in packaged volume can be achieved by using retractable diagonals.

[0047] As shown by a comparison of FIGS. 8A and 8B, the storage height H s is the storage height l of the batten restraint according to the embodiment described herein shown in FIG. 8B. d In Figure 8B, the battenless diagonals are not retracted in the stowed configuration as would be achievable if they were telescopically shortened. Thus, the battenless perimeter truss can achieve a significantly shorter stowed height than conventional systems.

[0048] If the component is made of elastomeric shape memory composite material, Sub-T gWhen the temperature is above the glass transition temperature, g Similar to folding the material over, the material can be folded over at the midpoint or at any desired location, so no hinge is required.

[0049] Exemplary embodiments of the design can be implemented with various versions of rigid or rigidizable materials, as described above. Exemplary embodiments of the invention utilize rigid diagonals made from low CTE carbon composite tubing, shape memory carbon composite (SMCC) for the longerons, gold-plated molybdenum wire for the conductive mesh, and Vectran® fabric composite for the reflector and inverted dome.

[0050] An advantage of the present invention over similar deployable space antennas is the fact that the stowed height is at least half as short as conventional configurations such as those described in U.S. Patent No. 5,680,145. This means that exemplary embodiments of the Batten Retractable Antenna can be launched using a rocket booster one size smaller than that required to launch conventional configurations. This represents a savings of tens of millions of dollars in launch costs alone.

[0051] The diagonals of the exemplary embodiments described herein may be telescoping diagonals so that the truss can be stowed at a height less than its fully deployed configuration.

[0052] In exemplary embodiments, the shape memory component may comprise a shape memory composite. The shape memory composite may comprise fibers held in a matrix or resin. In exemplary embodiments, the shape memory composite may be flexible at multiple locations along the length of the member or along the entire length of the member. In exemplary embodiments, the shape memory composite may return to a memorized configuration, such as a straight, circular, oval, curved, parabolic, spiral, or other predetermined shape, upon removal of an external force. The predetermined shape may be the shape of the structure that is maintained without the use of an external force. The predetermined shape may be defined by its relationship and connection to one or more other shape memory composites, envelopes, and / or other support structures described herein.

[0053] Exemplary shape memory composite materials include a substrate of one or more of carbon fiber, Vectran®, Kevlar®, fiberglass, glass fiber, plastic, and / or fiber metal. The substrate may include strands. The strands may be generally aligned along the length of the structure, may include one or more aligned arrangements, may be wrapped, spirally arranged, woven, or any combination thereof. The shape memory composite material may include a matrix around and / or between the substrates. The matrix may be silicone, urethane, or epoxy. Exemplary shape memory composite materials are described in commonly owned U.S. Patent Application Publication No. 2016 / 0288453, entitled "Composite Materials." Exemplary embodiments include a high-strain material to enable deformation. A high-strain material generally has the ability to strain more than 3% and not enter plastic deformation. In other words, the material may bend more than 3%.

[0054] In an exemplary embodiment, the shape memory composite material includes a fiber-to-resin volume fraction ratio that can be controlled to achieve desired shape memory retention even after extended storage in a folded / packaged state. An exemplary fiber-to-resin volume fraction ratio is 52-65, i.e., 52%-65% fiber or 48%-35% matrix or resin. The average fiber-to-matrix ratio is approximately 58%. The fiber may be carbon, Kevlar®, Vectran®, nylon, or others described herein, and the resin may be urethane, silicone, or epoxy, or others described herein as a matrix.

[0055] In an exemplary embodiment, a member constructed from a shape memory composite material may be electrically conductive. Some or all of the components may be electrically conductive. The component may be made electrically conductive by incorporating an electrically conductive material into the shape memory material. The component may include a metal powder, coating, wrapping, sheet, film, paint, strand, or combinations thereof. The electrically conductive material may be a fiber, a resin, a surface of a fiber, a surface of a component, or combinations thereof. In an exemplary embodiment, the shape memory composite component is electrically conductive, and the antenna shape is created by wrapping the component in a thin copper sheet. The copper sheet may be glued or otherwise bonded to the outer surface of the shape memory composite shaft.

[0056] The embodiments described herein may include a support structure. The support structure may be foldable and / or deformable. The support structure may be a dielectric film. The support structure may include a deformable member. The support structure may be an elongated member, a rod, a fabric, a mesh (net), a sheet, and combinations thereof. Exemplary embodiments include a support structure used as an antenna, a collector, a reflector, or other application. The support structure may be coupled to a shape memory composite, a conductive component, other components of the antenna, or combinations thereof.

[0057] In exemplary embodiments, additional structures may be used to deform and / or support the support structure and / or the conductive components. In exemplary embodiments, the additional structures may include flexible components, which may or may not have shape memory. The additional support structures may be coupled to the shape memory components and / or the support structure to couple the component portions together, define the deployed shape, support or form additional attachment points between the component portions, affect deployment, or contribute to the design of the antenna structure.

[0058] Exemplary embodiments described herein may use any combination of the features described herein. In exemplary embodiments, support structures and their applications, such as reflectors, antennas, collectors, etc., may include any combination of support structures, shape memory composite components, conductive components, and additional structures, whether separate component parts and / or integrated in one or more ways to function as two or more component parts. Exemplary embodiments include any combination of support structures, shape memory composite components, conductive components, and additional structures, including flexible components. Flexible components include component parts that can bend at any point or along their length. In exemplary embodiments, any combination of support structures, shape memory composite components, conductive components, and additional structures enables dynamic deformation of the non-structural components. As described herein, dynamic deformation of the non-structural components enables flexibility that can be defined by external forces that deform the components, but not in a preconfigured or structurally limited manner.

[0059] Exemplary embodiments described herein include a truss structure including a plurality of nodes and a plurality of structural members connected by the plurality of nodes. The plurality of structural members may comprise a plurality of longerons and a plurality of diagonals. The plurality of longerons may comprise deformable members. The plurality of diagonals may comprise rigid members.

[0060] Exemplary embodiments described herein may include a system having a truss structure described herein configured as a perimeter truss, a first support structure coupled to the perimeter truss, a reflective surface supported on the first support structure, a second support structure coupled to the perimeter truss, and a force element connected between the first support structure and the second support structure. The system may have a deployed configuration and a stowed configuration. The system in the stowed configuration may include a plurality of longerons in a deformed state. The deployed configuration may include a plurality of longerons in a memory state. The plurality of longerons may comprise a shape memory composite material.

[0061] An exemplary embodiment of the system may include a deployment system comprising one or more cables and multiple pulleys. The deployment system may be configured to apply tension to one or more cables to apply force to multiple longerons, thereby transitioning or holding the system in a stowed configuration.

[0062] The plurality of diagonals may comprise elastic members. The plurality of longerons may comprise a shape memory composite material.

[0063] It should be emphasized that many variations and modifications may be made to the embodiments described herein, and that the elements thereof should be understood to be among other acceptable examples. All such modifications and variations are intended to be within the scope of this disclosure and protected by the following claims. Furthermore, any of the steps described herein may be performed simultaneously or in a different order than the steps listed herein. Furthermore, it will be apparent that the features and attributes of specific embodiments disclosed herein may be combined in different ways to form additional embodiments, all of which are within the scope of this disclosure.

[0064] Certain terms may be used in the following description for reference purposes only and are therefore not intended to be limiting. For example, terms such as "above" and "below" refer to directions in the referenced drawings. Terms such as "front," "back," "left," "right," "rear," and "side" describe the orientation and / or location of a component or portion of an element within a consistent but arbitrary frame of reference, which becomes apparent by reference to the text and associated drawings that describe the component or element being described. Additionally, terms such as "first," "second," and "third" may be used to describe separate components. Such terms may include the words specifically mentioned above, derivatives thereof, and words of similar import.

[0065] Conditional language used herein, particularly "can," "could," "might," "may," "eg," and the like, unless otherwise specified or understood within the context in which it is used, is generally intended to convey that a particular embodiment includes certain features, elements, and / or conditions. However, such language also includes embodiments in which a feature, element, or condition is absent. Thus, such conditional language is generally not intended to imply that a feature, element, and / or condition is in any way required by one or more embodiments, or that one or more embodiments necessarily exclude undescribed components by another embodiment.

[0066] Additionally, the following terms may be used herein: The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to an item includes a reference to one or more items. The term "ones" refers to one, two, or more and generally applies to the selection of part or all of a quantity. The term "plurality" refers to two or more items.

[0067] As used herein, the terms "about," "substantially," or "approximately" with respect to any numerical value, range, shape, distance, relative relationship, etc., indicate appropriate dimensional tolerances that allow a portion or collection of components to function for the intended purpose described herein. Numerical ranges may also be provided herein. Unless otherwise indicated, each range is intended to include the endpoints and any quantity within the provided range. Thus, a range of 2 to 4 includes 2, 3, 4, and any portion between 2 and 4, such as 2.1, 2.01, and 2.001. Ranges also encompass any combination of ranges, such as 2 to 4 including 2 to 3 and 3 to 4.

[0068] As used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. These terms are not to be interpreted as excluding the presence of other features, steps or components.

[0069] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, in their specific form, or in connection with means for performing a disclosed function, or methods or processes for achieving a disclosed result, may be utilized to realize the invention in various of its forms, either separately or in any combination of such features, as appropriate.

[0070] Although the embodiments of the present invention have been fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications should be understood to be included within the scope of the embodiments of the present invention, as defined by the appended claims. Specifically, exemplary components are described herein. These components may be combined in any combination. For example, any component, feature, step, or portion may be integrated, separated, subdivided, removed, duplicated, added, or used in any combination while remaining within the scope of the present disclosure. The embodiments are merely illustrative and provide exemplary combinations of features, but are not limited thereto.

Claims

1. A batten-rest truss structure configured as a perimeter truss, the batten-rest truss structure comprising: A plurality of nodes; a plurality of structural members connected by a plurality of nodes; the plurality of structural members comprises a plurality of longerons and a plurality of diagonals, without any transverse or batten members; the plurality of longerons comprise deformable members and the plurality of diagonals comprise rigid members; a batten-retaining structure; a first support structure coupled to the perimeter truss; a reflective surface supported by a first support structure; a second support structure coupled to the perimeter truss; a force element connected between the first support structure and the second support structure; a deployment system comprising one or more cables and a plurality of pulleys; A system comprising:

2. The system of claim 1 , wherein the system comprises a deployed configuration and a stowed configuration, the system in the stowed configuration comprising a plurality of longerons in a deformed state.

3. The system of claim 2 , wherein the deployed configuration comprises the longerons in a memorized state.

4. The system of claim 3 , wherein the longerons comprise a shape memory composite material.

5. The system of claim 1 , wherein the deployment system is configured to apply tension to one or more cables to apply force to the plurality of longerons, thereby transitioning or retaining the system in a stowed configuration.

6. The system of claim 1 , wherein the plurality of diagonals comprise telescopic members.

7. The system described in claim 1, wherein the first support structure comprises a first dome of a particular shape when under tension, the second support structure comprises a second dome configured as an inverted dome that is an approximate mirror image of the particular shape, and the reflective surface comprises a conductive mesh, a non-conductive mesh, a metallized thin film, a polyimide thin film, or a polyester thin film.

8. The system described in claim 1, wherein the first support structure further comprises a support connection from the perimeter truss to the perimeter of the net, providing tension to the outer edge of the reflector surface and forming a tension drum surrounded by the perimeter truss.

9. A system as described in claim 1, wherein the system has an deployed configuration and a stowed configuration, and the height of the stowed configuration is approximately equal to or shorter than the length of the diagonal members by using an extendable diagonal member.

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