United States of America As Represented by the Secretary of the Air Force

Alliant Techsystems Inc.

Thomas W Murphey

Eric L Pollard

Jeremy A Banik

David Michael Murphy

Matthew M Botke

Joseph N Footdale

Michael Edward McEachen

Gregory E Sanford

Sungeun K Jeon

Emil Valentin Ardelean

Whitney D Reynolds

Laura A Stiles

Grant M Thomas

A modular deployable structure that includes at least two panels, one of which is configured to be pivotably attached to a further structure for deployment therefrom and return thereto. Interfaces pivotably interconnect each two panels, and are in the form of a pin clevis joint arrangement. Dogbone links are pivotably attached to the interfaces to effect pivoting of the panels. Linkage members extend adjacent to the panels and are pivotable relative to the dogbone links. The linkage members pivotably interengage one another, for example via gears. A drive mechanism effects pivoting of one of the linkage members to in turn effect synchronized pivoting of all of the linkage members and the panels.

Modular deployable structure

A spacecraft deployment mechanism employing a pair of bi-stable tape springs attached to a cylinder such that rotation of the cylinder extends or retracts the tape springs in opposite directions. The tape springs are fabricated such that they are stable when wrapped around a cylinder (stowed configuration) or when deployed and have a higher energy state when stowed than when deployed. A plurality of bi-stable tape spring mechanisms may be combined to create a deployment device that does not impart rotational torques to the spacecraft during deployment. Deployment may be accomplished by release of the stored energy in the coiled or packaged state progressing to the lower energy deployed state. Alternatively, a motor may be employed to rotate the cylinders for deploy or retrace the tape springs.

Deployable space boom using bi-stable tape spring mechanism

An improved test fixture to evaluate thin composite laminates commonly used in deployable space structures. The fixture is designed to impart a pure moment into the coupon, a necessary improvement to prior test methods where results are obtained by fitting material properties in a nonlinear structural analysis of the test. Fixture mechanics allow for direct calculation of the coupon flexural modulus and allowable flexural strain based on two key measurements, fixture displacement and applied load.

Device for testing thin specimens in pure bending

A reflector useful for communications, radar and sensing application in space and on earth includes thin shell gores emanating from a geometric center of the reflector at its hub. Gores are provided in a spiraled pattern and are in elastic connection to said hub and wrapped around their point of convergence at the hub when the reflector is stowed. The gores emanate from the geometric center of the reflector hub at their elastic connection to the hub when they are deployed and operational as a reflector with a point of convergence to promote operation as a reflector. Thin shell gores can have an inner perimeter and outer perimeter, can be provided in a spiraled pattern, and can be interlocked at their outer perimeter, or in-between their inner and outer perimeter, while also remaining in elastic connection at their inner perimeter to said hub.

Deployable shell with wrapped gores

Multi-axis compliant hinges used in conjunction with strut elements to form a collapsible structure. The hinges behaves similar to a pin-clevis hinges but have increased compliance during the deployment sequence allowing connected struts to translate and rotate finite amounts relative to each other. Once deployed, the hinges lock out to form strong and stiff joints. The hinge uses two opposing resilient tape spring surfaces for each axis. The opposing tape spring surfaces of each axis are joined together by rigid inserts at their ends opposite the common connection point and to which structural members or struts are connected.

Multi-axis compliant hinge

A non-planar surface support structure that is compatible with deployable thin shell reflector segments. The structure is composed of multiple four strut closed loops connected to compliant hinges at the nodes to create an effective surface. The deployed surface shape is determined by the strut lengths (L) and the node locations and the packaged compatibility constraint in which L+L&#x2212;L&#x2212;Lapproximately equals zero. Each of the compliant hinges have degrees of freedom such that the compact configuration of the support structure is obtained by the translation of two opposite nodes of each loop upwards and the remaining two nodes downwards in a continuous process until all struts are approximately parallel and tightly bundled and the hinges lock out all degrees of freedom in the deployed configuration.

Deployable structures with quadrilateral reticulations

Flexible and resilient masts are connected by flexible and resilient inner and outer spars, and flexible cords radially connect the spars. A flexible material is attached to the cords. The assembly is wrapped around a rotatable cylindrical drum in the structure's stored configuration. Each mast is flexible only about an axis lying parallel to the axis of rotation of the drum, and is otherwise rigid. Each mast is linear when extended and has a bending stress when deformed into a non-linear configuration, such as when wrapped around the drum. When the structure is in its stored configuration, a restraining device opposes the bending stress and another prevents the drum from rotating. Upon disengagement of the restraining devices, the stored bending strain energy forces the drum to rotate and the masts to extend into the deployed configuration and thereby unfurl the flexible material.

Structure for storing and unfurling a flexible material

A deployable truss is formed from a plurality of column members connected at their ends where at least some of the column members are formed from column assemblies, each including a plurality of strut members that are at least connected to each other at a first and second end of the column assembly. For added rigidity, strut members of a column assembly may be connected to each other between the first and second ends using, for example, a rigidizable resin, a fixed spacer, or a deployable spacer. Connecting strut members between the ends of the column assembly provides mutual bracing to the strut members and decreases the free buckling length of the individual strut members. Spacers are preferably configured to radially space the strut members away from the longitudinal centerline of the column assembly to increase its moment of inertia, and hence its buckling strength.

Deployable truss having second order augmentation

A collapsible and deployable hierarchical open lattice assembly comprised of hinge boxes of 12 battens connected by hinge nodes. The hinge nodes are made of a plurality of resilient flexure joints, each joint connected to a batten and giving said batten a 90-degree in-plane rotation capability with a neutral-shaped flexure in a deployed state and a deformed-shaped flexure in a compressed state, whereby a restorative moment is created tending to return said flexure to its neutral state. One or more trusses are formed by sets of four longerons connected to the hinge boxes by the resilient flexure joints. Multiple hub boxes connected by longerons may be used to create a hierarchical truss of trusses in either two or three dimensions. These assemblies may be collapsed to a linear dimension by shearing the hub boxes and trusses in a parallelogram manner. The folding kinematics occur in three stages, which may be performed either sequentially or simultaneously. Initially the trusses connecting the hub boxes are sheared. Then the hub boxes and trusses are sheared in one common dimension to reduce the assembly to a two-dimensional, planar configuration. Finally the hub boxes and trusses are sheared in a perpendicular common dimension to reduce the assembly to a one-dimensional, linear configuration.

Deployable heirarchical structure

An elastic space-deployable boom of carbon fiber reinforced plastic or other resilient material having an open substantially triangular cross-section when deployed and stowed with a flattened cross-section about a circular hub.

Triangular rollable and collapsible boom

A self-deployable, monolithic, open-lattice frame structure of resilient, tape-spring members. The structure is comprised of three or more longitudinal prismatic tape-spring members (longerons) and non-prismatic tape-spring members (battens) that are connected transversely to the longerons. The longerons can be reconfigured in a z-folding manner to compact the structure. The batten members have a twist at each end of the same magnitude and sense, such that when connected to the longerons, the concave surfaces of the battens substantially face along the longitudinal direction of the frame structure. This batten shape permits them to nest within adjacent battens when the structure is compacted.

Tape-spring deployable boom

A resilient flexure has one end attached within a cavity in a rigid member, and the other end attached within a cavity in a structural mode. The cavities are shaped to limit the flexure's bend radius. The member and the node have mating surfaces that abut to constrain the amount of rotation of the member. The aforementioned elements are shaped to prevent the strain in the flexure from exceeding its design limit when the joint is at its maximum angular deflection and the attached member is fully collapsed.

Resilient joint for deployable structures

A tape-spring shaped, articulating member used in deployable structures having a resilient, compliant hinge region and rigid non-hinge regions, thereby enabling a smaller fold radius and greater packaging efficiency. The increased compliance in the hinge region may be obtained by using a more compliant material in the hinge region or reducing the cross-sectional area in the hinge region. The hinge region may be reinforced with integrated shape memory alloy features serving as folding mandrels, to enhance structural stiffness and strength performance of the hinge, and to exhibit authority over the rate and sequencing of strain release when deployed.

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Albuquerque, NM, United States of America

Thomas W Murphey