A shape-morphing space frame (SMSF) utilizing the linear bistable compliant crank-slider mechanism (LBCCSM). The frame's initial shape is constructed from a single-layer grid of flexures, rigid links and LBCCSMs. The grid is bent into the space frame's initial cylindrical shape, which can morph because of the inclusion of LBCCSMs in its structure. The design parameters include the frame's initial height, its tessellation pattern (including the unit cell bistable elements' placement), its initial diameter, and the resulting desired shape. The method used in placing the unit cell bistable elements considers the principle stress trajectories. Two different examples of shape-morphing space frames are presented herein, each starting from a cylindrical-shell space frame and morphing, one to a hyperbolic-shell space frame and the other to a spherical-shell space frame, both morphing by applying moments, which shear the cylindrical shell, and forces, which change the cylinder's radius using Poisson's effect.

A rotary joint includes a socket rod having a socket rod flange with an at least partly spheroid concave bearing surface at a first end, a housing nut encircling the socket rod and having a threaded wrenching head, and a ball rod having an at least partly spheroid convex bearing surface and threaded side walls around the bearing surface. The diameter of the threaded side walls of the ball rod corresponds to a diameter of the threaded wrenching head of the housing nut.

A rotary joint includes a socket rod having a socket rod flange with a basically spheroid concave bearing surface at a first end, a housing nut encircling the socket rod and having a threaded wrenching head, and a ball rod having a basically spheroid convex bearing surface and threaded side walls around the bearing surface. A diameter of the threaded side walls of the ball rod corresponds to a diameter of the threaded wrenching head of the housing nut. First guiding tracks are on the concave bearing surface oriented into a first swivelling direction, the socket rod being swivable to the ball rod along the first guiding tracks into the first swivelling direction. Second guiding tracks are on the convex bearing surface and oriented into a second swivelling direction, the socket rod being swivellable to the ball rod along the second guiding tracks into the second swivelling direction.

A modular unit for forming a multiple member joint includes: an elongate body; a bracket attached adjacent an end of the elongate body, the bracket located around a longitudinal axis of the modular unit; a plurality of connectors associated with the bracket with a position retention mechanism, the plurality of connectors extending from the end of the elongate body parallel to a longitudinal axis of the modular unit; and one or more connector joints attached at a distal end of the plurality of connectors, wherein the one or more connector joints are adapted to join with one or more connector joints of connectors extending from connectors of an adjoining modular unit.

A modular unit for forming a multiple member joint includes: an elongate body; a bracket attached adjacent an end of the elongate body, the bracket located around a longitudinal axis of the modular unit; a plurality of connectors associated with the bracket with a position retention mechanism, the plurality of connectors extending from the end of the elongate body parallel to a longitudinal axis of the modular unit; and one or more connector joints attached at a distal end of the plurality of connectors, wherein the one or more connector joints are adapted to join with one or more connector joints of connectors extending from connectors of an adjoining modular unit.

A shape-morphing space frame (SMSF) utilizing the linear bistable compliant crank-slider mechanism (LBCCSM). The frame's initial shape is constructed from a single-layer grid of flexures, rigid links and LBCCSMs. The grid is bent into the space frame's initial cylindrical shape, which can morph because of the inclusion of LBCCSMs in its structure. The design parameters include the frame's initial height, its tessellation pattern (including the unit cell bistable elements' placement), its initial diameter, and the resulting desired shape. The method used in placing the unit cell bistable elements considers the principle stress trajectories. Two different examples of shape-morphing space frames are presented herein, each starting from a cylindrical-shell space frame and morphing, one to a hyperbolic-shell space frame and the other to a spherical-shell space frame, both morphing by applying moments, which shear the cylindrical shell, and forces, which change the cylinder's radius using Poisson's effect.

A rotary joint includes a socket rod having a socket rod flange with a basically spheroid con-cave bearing surface at a first end, a housing nut encircling the socket rod and having a threaded wrenching head, a ball rod having a basically spheroid convex bearing surface and threaded side walls around the convex bearing surface, and a joint actuator configured to actuate relative movement of the socket rod flange and the ball rod. A diameter of the threaded side walls of the ball rod corresponds to a diameter of the threaded wrenching head of the housing nut.

An adjustable structure (1) comprising a first structural layer (10) defined by a first array of extendable and/or retractable rods or beams (11, 11a, 11b) pivotally connected to each other at their ends and a second structural layer (20) connected to the first structural layer (10) and defined by a second array of extendable and/or retractable rods or beams (21, 21a, 21b) pivotally connected to each other at their ends, wherein at least a portion of the second layer (20) is outside the volume defined by the first structural layer (10) and the extendable and/or retractable rods or beams in the second array are more densely packed than the extendable and/or retractable rods or beams in the first array.

A strut connector for use with a hollow strut having at least one a pair of opposed openings formed in the strut. A pair of identical connector portions are rotatably coupled together, with one of the connector portions inverted. Each connector portion is a flat blade having a body portion and an arm portion extending from the body portion. The body portion has a first hole and a second hole. The arm portion has at least one tab extending from the arm portion at an angle. The arm portions are coupled together via the first hole, then rotated to engage respective openings on the strut with the tabs. The second holes are aligned and a fastener secured through the second holes.

A strut connector for use with a hollow strut having at least one a pair of opposed openings formed in the strut. A pair of identical connector portions are rotatably coupled together, with one of the connector portions inverted. Each connector portion is a flat blade having a body portion and an arm portion extending from the body portion. The body portion has a first hole and a second hole. The arm portion has at least one tab extending from the arm portion at an angle. The arm portions are coupled together via the first hole, then rotated to engage respective openings on the strut with the tabs. The second holes are aligned and a fastener secured through the second holes.