Abstract: Disclosed is a structural vibration damping device, which comprises a piezoelectric element adapted to be mounted on a structure, a shunt circuit inserted between two electrodes of the piezoelectric element, and an electric circuit for selectively opening and closing the shunt circuit. In this damping device, the electric circuit is operable, when a voltage between the electrodes of the piezoelectric element has a positive or negative extreme value due to a vibration of the structure, to close the shunt circuit so as to allow a current to flow between the electrodes of the piezoelectric element, and, when the current is reduced to zero, to open the shunt circuit so as to preclude the current flow until a voltage between the electrodes of the piezoelectric element subsequently has the extreme value. Further, each of the shunt circuit and the electric circuit is designed to be operated using only a power generated by the piezoelectric element.

Abstract: Disclosed is a structural vibration damping device, which comprises a piezoelectric element adapted to be mounted on a structure, a shunt circuit inserted between two electrodes of the piezoelectric element, and an electric circuit for selectively opening and closing the shunt circuit. In this damping device, the electric circuit is operable, when a voltage between the electrodes of the piezoelectric element has a positive or negative extreme value due to a vibration of the structure, to close the shunt circuit so as to allow a current to flow between the electrodes of the piezoelectric element, and, when the current is reduced to zero, to open the shunt circuit so as to preclude the current flow until a voltage between the electrodes of the piezoelectric element subsequently has the extreme value. Further, each of the shunt circuit and the electric circuit is designed to be operated using only a power generated by the piezoelectric element.

Abstract: A collapsible truss structure having a shape of a rectangular parallelepiped when expanded is an open truss framework made up of skeletal members pin jointed together by joint connectors to form sixteen rectangular bays, four of which have diagonal braces, and supports panels for covering one face of the structure. The joint connectors permit the structure to be folded by power means in two directions into a compact slab for storage and/or transportation with the panels assembled therewith, while elastically biasing means automatically unfold the structure into its expanded state. Planar, single-curvature, and double-curvature panels can be thus supported. This structure can be optionally assembled with other structures to form larger structural assemblies.

Abstract: A vibration control system for a structure comprises an actuator connected in a truss structure as a structural member, for varying an axial stiffness in response to a control signal, at least one vibration sensor for producing a sensor signal representing a vibratory motion of the structure, and a controller for controlling vibrations of the structure by producing the control signal in accordance with the sensor signal. Preferably, the actuator comprises inner and outer tubes axially movable relative to each other, and a piezoelectric element which can change the axial stiffness of the actuator by allowing and preventing the relative movement between the inner and outer tubes.

Abstract: A collapsible truss structure in a basic form comprises eight joint connectors, twelve skeletal bars pivotally connected at their ends by the joint connectors, a diagonal bar or bars, and a slide hinge, and in its expanded or deployed state is in the shape of a rectangular parallelepiped formed by the twelve bars, the diagonal bar or bars being pivotally connected at its one end to one joint connector and extending diagonally within the deployed structure toward the most remote joint connector or connectors, near which the other end or ends of the diagonal bar or bars are pivotally connected to the slide hinge slidably fitted around one of the bars. The structure is collapsed by sliding the slide hinge away from said most remote joint connector. Lenghts of flexible bracing material can be stretched diagonally across bars of the structure to stably preserve the deployed state.

Abstract: A deployable truss composed of a plurality of three-dimensional truss units.

Abstract: A collapsible, or deployable, truss unit to be combined with a multiplicity of other similar units for the construction of, typically, medium to large size frameworks for use in outer space. Generally of boxlike shape when deployed, the truss unit comprises two opposite end truss assemblies of rectangular or quadrilateral shape, and an intermediate truss assembly of similar shape interposed therebetween and linked thereto via additional truss members. Two opposite ones of the four truss members of the intermediate truss assembly have each a movable hinge assembly mounted thereto for longitudinal displacement. Each movable hinge assembly has two diagonal truss members pivoted thereto each at one end, the other ends of the diagonal truss members being pivoted to the respective end truss assemblies.

Abstract: A collapsible, or deployable, truss unit to be combined with a multiplicity of other similar units in an array for the construction of, for example, medium to large size frameworks in outer space. Each truss unit comprises two substantially rectangular arrangements of four rigid side members pivotally joined to one another, to be directed toward the opposite sides of the framework constructed, and four rigid cross members extending between the joints of the two rectangular arrangements of the side members. A flexible brace or braces are arranged diagonally of each rectangular arrangement of the side members. Two diagonally opposite ones of the four cross members have each a hinge assembly mounted thereto for longitudinal displacement. Each movable hinge assembly has two rigid diagonal members pivoted thereto each at one end, the other ends of the diagonal members being pivoted to two diagonally opposite ones of the four joints of one rectangular arrangement of side members.