Trw Limited

Northrop Grumman Systems Corporation

Tew Inc.

Trw Vehicle Safety Systems Inc.

Allen J Bronowicki

George R Dvorsky

Theodore W Nye

Richard E Wyse

Abner Kaplan

Todd L Mendenhall

Raymund A Manning

Milton H Gran

Brian K Blackburn

Scott B Gentry

Joseph F Mazur

Jonathan W Arenberg

Nicholas Robert Steffen

Jack R Bohn

Dean R Dailey

Martin Richard Flannery

Steven P Kuritz

Teh Hwei Lee

Claude I Kansaku

Charles F Lillie

A vibratory isolator in one example comprises at least one uniform mass inertia component and at least one uniform compliant component which are configured to exhibit a vibratory bandgap and which are configured to exhibit shear/bending coupling. A further implementation of the invention comprises a vibratory isolator comprised of an isolator and a plurality of disk inertias affixed to the isolator such that the vibratory isolator exhibits a vibrational bandgap in a predetermined frequency range.

Vibratory bandgap device

A magnetically damped mounting and isolation system with pointing capability. A payload is mounted to an isolator plate, a base plate is mounted to a satellite or other space vehicle, and the isolation system provides damping of all six degrees of freedom of isolator plate motion relative to the base plate. Three bidirectional magnetic dampers are connected between the isolator plate and the base plate and arranged to provide the required amount of temperature-independent damping. The bidirectional magnetic dampers can be connected to the base plate and the isolator plate in different configurations based on desired mass and natural frequency characteristics. Flexures which statically position the isolator plate are also designed to optimize normal modes of vibration. The isolation system may include a motion amplification feature to increase magnetic damping effectiveness, and the isolation system may also include active positioning of the payload relative to the satellite.

Magnetically damped isolator and pointing mount

A positioning boom disposed between a space-based observatory platform and its instrument payload provides thermal and dynamic isolation as well as fine pointing and momentum control. The inventive system isolates a sensitive payload from a warm, dynamically noisy spacecraft, which includes a sunshield. Isolation is required in terms of dynamics and heat flow, both in terms of the absolute level and its variance (thermal isolation). The present invention provides intrinsic control over momentum buildup (which is due to the separation of the center of pressure from the center of mass). The space-based platform also provides a view (field of regard) to at least half the sky (in the anti-sun direction).

Isolating positioning boom for instrument platform

Modular control patches including assemblies of sensors and actuators are provided to impart or control vibration of foundation members such as struts in aerospace apparatus. Local digital electronic control means is associated with each control patch assembly. Programmable digital compensators in the control permits operation of the patches to be remotely varied. Patches are attached mechanically or by chemical bonding to the outside of the struts so that the electronics can be selectively removed and replaced. The patch being the sensors and actuators may also be attached or embedded with a composite structure.

Digital control of smart structures

Modular control patches including assemblies of sensors and actuators are provided to impart or control vibration of foundation members such as struts in aerospace apparatus. Local analog electronic control means is associated with each control patch assembly. Patches are attached mechanically or by chemical bonding to the outside of the struts. The corresponding electronics can be selectively removed and replaced. The patch being the sensors and actuators may also be attached or embedded with a composite structure.

Smart structures for vibration suppression

A vibration isolation and precision pointing device, and a related method for its operation, for reducing vibrational disturbances on a payload platform, which is subject to vibration transmitted from a base platform and to other possible vibrational disturbances applied directly to the payload itself or to the payload platform. The invention includes a complementary combination of passive isolation and active isolation in parallel between the base and payload platforms, together with a precision positioning system that greatly reduces vibration at very low frequencies. Each isolation device, of which there are three pairs arranged to damp vibration in three axes, includes, in one embodiment, a passive spring to reduce coupling of vibration at higher frequencies and to fulfill a static load bearing function, and an active actuator element, in the form of a voice coil actuator, for applying active compensation over a selected bandwidth of frequencies below that over which passive isolation is most effective. Another disclosed form of each isolation device includes an elastic tube bendable by piezoelectric actuators and having a flexure that transmits the bending force to the payload platform along a single selected axis. In one preferred embodiment of the invention, three pairs of isolation devices are arranged on mutually orthogonal planes that intersect at the center of mass of the payload. As a result, translational vibration in the orthogonal planes is decoupled from rotation of the payload.

Semi-active vibration isolator and fine positioning mount

A coating composition and method are disclosed for reducing vibration and noise when applied to a structure such as in transportation and industrial equipment systems. The coating composition of the present invention includes a viscoelastic material with discrete stiff fibers suspended therewithin. The viscoelastic material is preferably selected from acrylics, silicones and polyurethanes, and the discrete fibers are preferably carbon fibers. The manipulation of the fiber volume fraction within the viscoelastic material, the dimension of the fibers, the orientation of the fibers within the composition and the fiber and viscoelastic material selections results in coating materials that enhance the reduction of vibration and noise

Fiber reinforced viscoelastic material composites for passive damping

A self-exciting vibratory device for producing vibration signals in a housing includes actuator means (12) attached to housing (16), sensor means (14) attached to housing (16) and electronics module (18) connecting actuator means (12) and sensor means (14). Actuator means (12) creates vibration signals within housing (16). Sensor means (14) senses the vibration signals created by actuator means (12). Electronics module (18) amplifies and phase shifts the vibration signals sensed by sensor means (14) and containing resonant modes of vibration of housing (16). Electronics module (18) then supplies these amplified, phase shifted signals to actuator means (12) to enhance the vibration of housing (16) at the dominant mode of vibration of housing (16).

Apparatus and method for producing structural and acoustic vibrations

A composite structure of elastic and viscoelastic components in which dynamic loads are effectively damped by repeated transmission through viscoelastic layers. Multiple viscoelastic layers and stiff segmented elastic layers are formed on the outside of a tubular layer of soft elastic material, to provide the damping effect without having to form additional layers inside the tubular layer of soft elastic material. The transition temperatures above which the viscoelastic layers become substantially less stiff may be selected to be different for each layer, to provide increased damping efficiency over a broadened operative temperature range.

Composite damping structures and related method

A structure includes a foundation member and multiple piezoelectric actuator/sensor elements disposed transversely about the structure. The elements are bound to the face of the foundation member to permit force transmission between the elements and the foundation member. The elements include restriction plies orientated oppositely for alternating transverse elements. The elements have a preferred direction of motion and when two adjacent elements are oppositely poled, this relates to a torsional motion between the elements and the foundation member. When four elements are spaced about a cylindrical foundation member and selectively poled, axial, bending and torsional motion between the elements and foundation member is effected.

Activated structure

A composite structure of elastic and viscoelastic components in which dynamic loads are effectively damped by transmission through the viscoelastic components. The structure includes a continuous sandwich comprised either of a single elastic layer enclosed by two viscoelastic layers or of a single viscoelastic layer enclosed by two elastic layers such that the sandwich has little stiffness in any intended direction of loading, and two segmented elastic layers having stiffness in a desired loading direction. The segmented layers have alternating segments and gaps and are disposed one on each side of the viscoelastic layer in such a manner that the gaps of one segmented layer overlap the segments of the other segmented layer. Dynamic loads in the loading direction are transmitted back and forth from one segmented layer to the other, through the continuous sandwich layer containing the viscoelastic material, which thereby provides a high degree of damping. Static loads in the loading direction are transmitted through the elastic material in the continuous sandwich layer. By appropriate selection of elastic materials, the structure can be made suitable for the damping of loads in all directions while maintaining considerable strength and static stiffness. Appropriate selection of fiber orientations can increase the damping effect on either axial and bending loads, or on torsional loads.

Growing community of inventors

Laguna Niguel, CA, United States of America

Allen J Bronowicki