Abstract: An end cap for an arc spring in a torsional vibration damper having a cylindrical section for engaging with the arc spring and a radial section at one end of the cylindrical section for engaging with an input or output side of the torsional vibration damper, the end cap being producible by shaping from a metal sheet. A torsional vibration damper for elastic transmission of torque between an input side and an output side including the described end cap for transmission of force between one of the sides and the arc spring.

Abstract: A laminated acoustic building panel comprises a pair of plasterboard substrates which are bonded together by an adhesive layer, the panel having a dynamic Young's modulus of 0.1 to 5 GPa and a damping loss factor of 5-30% (?=0.05-0.3), and the ratio of the adhesive to the applied surface area of the substrates being 80-250 g/m2. The laminated panel is relatively soft in construction and hence sound waves caused by knocking or impact noise is surprisingly damped using considerably less adhesive than known panels. The use of soft substrates and less adhesive significantly reduces the weight of the panel. Furthermore, the use of less adhesive significantly reduces costs and makes production easier.

Abstract: A glazing unit having improved vibroacoustic damping properties, including: at least one glass sheet; at least one vibroacoustic damping strip, the strip including at least one element made of damping material and the strip being fastened to one of the faces of the glass sheet. The face of the strip facing the glass sheet has a surface area in contact with the glass sheet which is strictly inferior to the surface area of the face of the strip facing the glass sheet. The glazing unit makes it possible to damp noise and vibrations while taking up little space.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: A shielding device is provided with a shielding element, which can be used for the thermal and acoustic shielding of components in a combustion engine. The mounting of the shielding device is such that thermal, acoustic and vibration transmission from hot, loud and vibrating components in the engine compartment or underbody area to a vehicle body is isolated.

Abstract: Methods for vibration and acoustic abatement. The methods comprise providing a substrate with a composite layer deposited thereon, the substrate receiving a vibration energy sufficient to provide at least one bending wave therein, and converting at least a portion of the vibration energy sufficient to cause the at least one bending wave to at least one shear wave in at least a portion of the composite layer. The composite layer comprises an elastomeric polymer matrix comprising carbon nano tubes dispersed or distributed therein. Articles with the composite layer comprising carbon nano tubes disposed thereon are also disclosed and described.

Abstract: PROBLEMS The present invention provides a sound absorbing structure that enables a sound absorbing rate thereof to be raised in a low-frequency region or medium-high frequency from around 500 Hz to 10 KHz, and a thickness thereof to be reduced. SOLUTIONS The sound absorbing structure has: a non-air permeable sheet molding object having, on one surface side thereof, a plurality of cavities including recesses formed by bending; and a non-air permeable surface sheet which is layered on the sheet molding object, on a cavity open-top side surface thereof, so as to cover open-top of the plurality of cavities, wherein the surface sheet is fixed at outer peripheral sections of the sheet molding object 11 and is not fixed to the sheet molding object at portions between adjacent cavities.

Abstract: An improved vibration damping apparatus is provided for use with window structures, including windows used in vehicles, aircraft, and spacecraft. The vibration damping system includes at least two separate layers of solid material that are typically substantially clear at visible wavelengths, in which the two layers are spaced-apart by a predetermined distance to form a space or gap therebetween. This gap will be of a size and shape to enhance vibration damping when it is filled with a gaseous compound, such as air. The air-film vibration damping system created by the above structure can be applied to an external pane of a window structure, or to the interior pane of a window structure, or perhaps to both an exterior pane and an interior pane of the same window structure, if desired.

Abstract: Damping material is installed on a structure by moving a material placement head over the structure, and using the head to place the material on the structure.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies. The method can further include forming a skin by positioning a third ply of composite material against a second tool surface offset from the first tool surface, and attaching the stiffener to the skin by co-curing the first, second and third plies of composite material.

Abstract: A method for attaching a protective structure to a feed beam of a rock drilling rig, and a protective structure for a rock drilling rig. The protective structure is at least partly arranged around the feed beam so that as the feed beam bends in a bending direction of its longitudinal axis and/or twists about its longitudinal axis in a twisting direction, the protective structure substantially maintains its original shape.

Abstract: A noise and vibration mitigating mat having top and bottom surfaces comprises a first layer formed of recycled bound rubber product, the first layer having a contoured bottom surface and a generally flat top surface, a second layer on the top surface of the first layer, the second layer being formed of a fabric and a third layer on the second layer and being formed of recycled rubber product.

Abstract: A pneumatic tire with a noise damper made of a spongelike multi-cellular material is disclosed. The noise damper is divided into small dampers to improve the high-speed durability of the tire. The noise damper is provided with a water-impermeable outer coating to prevent water from infiltrating into the spongelike multi-cellular material during transporting, store keeping and the like.

Abstract: Mobile soundproof enclosure with changeable internal room shape and optional ventillation noise cancelling device consisting of a frame that can be assembled and disassembled by a single person without using tools and that in disassembled state is small enough to fit in a trunk of a car; a cover made with flexible sound absorbent sheet material creating completely enclosed room with double walls with air space in between, corner sound traps made with flexible sound absorptive sheet material that can be individually positioned to change internal shape of the room and an air vent noise cancelling device made with flexible sound absorbing sheet material having inlet portion, which enters a center portion at an angle, the center portion larger than the inlet portion and outlet portion which exits the center portion at an angle; the whole enclosure can be disassembled to compactly fold for easy storage or transportation.

Abstract: A glazing unit having improved vibroacoustic damping properties, including: at least one glass sheet; at least one vibroacoustic damping strip, the strip including at least one element made of damping material and the strip being fastened to one of the faces of the glass sheet. The face of the strip facing the glass sheet has a surface area in contact with the glass sheet which is strictly inferior to the surface area of the face of the strip facing the glass sheet. The glazing unit makes it possible to damp noise and vibrations while taking up little space.

Abstract: An improved vibration damping apparatus is provided for use with window structures, including windows used in vehicles, aircraft, and spacecraft. The vibration damping system includes at least two separate layers of solid material that are typically substantially clear at visible wavelengths, in which the two layers are spaced-apart by a predetermined distance to form a space or gap therebetween. This gap will be of a size and shape to enhance vibration damping when it is filled with a gaseous compound, such as air. The air-film vibration damping system created by the above structure can be applied to an external pane of a window structure, or to the interior pane of a window structure, or perhaps to both an exterior pane and an interior pane of the same window structure, if desired.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: A device for damping of vibrations for an item of equipment comprising a structure to which a first element and a second fragile element having to be protected from the vibrations are coupled. The device comprises first piezoelectric transducer means inserted between the structure and the first element and charged with converting energy of vibration of the structure into electric energy, at least one sensor coupled to the structure and arranged to deliver measurement signals representative of vibrations, control means electrically supplied by the electric energy generated and charged with deducing at least one amplitude of movement to compensate at least partially for the vibration, and to deliver control signals representative of each determined amplitude, and second piezoelectric transducer means inserted between the structure and the second element and charged with converting the control signals into movement to damp at least partially for the second element the vibrations.

Abstract: The invention relates to a cladding part for components. The cladding part has at least two areas with different vibration damping properties. The different areas make it possible in a simple manner to meet partly conflicting requirements for cladding parts of the components in an optimum manner. The components include medical examination devices.

Abstract: A glazing unit with an improved vibroacoustic damping property including at least one sheet of glass and at least one vibroacoustic damping strip that is attached to at least one of the faces of the glass sheet and that includes at least one component made of damping material having a loss factor greater than 0.2. The strip is not joined to any other device on the opposite side from the glass sheet and the component made of damping material has a Young's modulus greater than 800 MPa, at 20° C., for a particular frequency corresponding to the critical frequency of the glazing unit to within plus or minus 30%.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: An active noise control apparatus and an active noise control system for reducing noise using an active vibrator, such that edges ? of the vibrator (i.e. genesis locations of a bending moment of force caused by the vibrator) agree with positions ? on a distribution of the bending moment of force caused by noise vibration of a panel, and such that the edges ? of the vibrator are aligned with the positions ? on the panel where a sign, of the distribution of the bending moment of force over the panel caused by the noise vibration, reverses. As a result, a control vibration approximate to the noise vibration can be excited. Accordingly, when the vibrator is fixed by agreeing the edges ? of the vibrator with the positions ? determined by noise frequency desired to be reduced, noise due to a target noise frequency can be effectively reduced.

Abstract: An improved acoustically and thermally insulating fire-retardant composite material suitable for use in structures such as buildings, appliances, and the interior passenger compartments and exterior components of automotive vehicles is provided. The material is comprised of at least one airlaid fibrous layer of controlled density and composition and incorporating suitable binding agents and additives as needed to meet expectations for noise abatement, fire-retardancy, and mildew resistance. Separately, an airlaid structure which provides a reduced, controlled airflow therethrough useful for acoustic insulation is provided, and which includes a woven or nonwoven scrim. A process for the production of the fire retardant nonwoven material is also provided.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: A sound absorption element for means of transport, in particular for aircraft, comprising at least one sound absorption panel arranged on a base panel with the base panel comprising a multitude of recesses, in particular a hole grid or the like, for the transmission of sound. According to the invention, the sound absorption panels are each framed by a frame, wherein on the at least one frame at least in some sections a transition profile, in particular to prevent fatigue fractures due to stepwise changes of rigidity between the at least one frame and the base panel is arranged. Due to the base panel comprising a multitude of recesses, in particular comprising a hole grid, in connection with the sound absorption panels an air-permeable sound absorption element can be achieved.

Abstract: A component with a first number of natural modes of vibration. An insert may be coupled to the component. The insert may have a second number of natural modes of vibration which is a different number than the first number of natural modes of vibration of the component. The insert helps damp vibrations in the component when the component is vibrated.

Abstract: A beam 14 having, at one end, a tie-point 11 screwed to reference location 12 of vibrating panel 15. At the other end of beam 14 is rubbing-point 13. Rubbing-point 13 is pushed into contact with panel 15 at contact location 17 by the flexibility of beam 14. Direct rubbing occurs between 13 and 17 during vibration. But a friction linkage 18 (FIG. 1B) can be mounted between beam point 13 and panel location 17 to redirect rubbing direction and/or to amplify friction movement. Vibration of panel 15 will cause slippage (rubbing) between point 13 and location 17, therefore creating friction dissipation of vibration energy. Construction of beam 14 can be complex to include more rubbing-points (FIG. 2, 3, 4) or more rubbing pieces (FIG. 1A, 1C) that can rub with each other to create more friction dissipation.

Abstract: A glazing unit with an improved vibroacoustic damping property including at least one sheet of glass and at least one vibroacoustic damping strip that is attached to at least one of the faces of the glass sheet and that includes at least one component made of damping material having a loss factor greater than 0.2. The strip is not joined to any other device on the opposite side from the glass sheet and the component made of damping material has a Young's modulus greater than 800 MPa, at 20° C., for a particular frequency corresponding to the critical frequency of the glazing unit to within plus or minus 30%.

Abstract: A resonant frequency adjustor for mounting onto an exhaust pipe of an exhaust system of a vehicle adjusts the resonant frequency(s) of the exhaust pipe to minimize or control vibration transmitted to the vehicle and/or to tune the sound emitted by the exhaust system. The resonant frequency adjustor includes a base mounted to the exhaust pipe, an isolator attached to the base, a stud attached to and extending from the isolator, and a mass located on the stud. A gross adjustment of the vibration of the exhaust pipe may be achieved by varying the location of the resonant frequency adjustor on the exhaust pipe. A fine adjustment of the vibration of the exhaust pipe may be accomplished by adjusting the position of the mass on the stud.

Abstract: A vibration damping device capable of maintaining high vibration damping effect, and a bucket for a construction machine. The vibration damping device has a laminated plate (20) having at least its inner region fixed in a noise-emitting base material (11), the inner region being a region (G) other then a region which becomes a loop in a vibration mode when the base material (11) is vibrated in a vibration mode with a predetermined frequency.

Abstract: A sound absorbing element, in one example, includes a first wall area, a second wall area as well as a plurality of spring elements. In this arrangement, the first wall area and the second wall area are arranged so as to be spaced apart by a clear space. In one example, the plurality of spring elements are arranged in the clear space and connect the first wall area and the second wall area to each other. By pre-tensioning the plurality of spring elements to a state in which their spring constant approaches zero, significant decoupling between the first and the second wall areas may occur, with accompanying sound noise reduction.

Abstract: A vibration damping device capable of maintaining high vibration damping effect, and a bucket for a construction machine. The vibration damping device has a laminated plate (20) having at least its inner region fixed in a noise-emitting base material (11), the inner region being a region (G) other then a region which becomes a loop in a vibration mode when the base material (11) is vibrated in a vibration mode with a predetermined frequency.

Abstract: An acoustic isolator for attenuating through-tool acoustic signals comprises a plurality of u-shaped link members, where each link member has two sets of ears. A plurality of yoke members are adapted to fit between cooperating sets of ears. A plurality of pins connect the plurality of u-shaped link members to the plurality of yoke members for providing limited flexural compliance. The isolator may be made from metallic and/or composite materials.

Abstract: A muffler hanger including: a rubber annular portion; a rubber arm constituting an elastic support portion for the muffler; an upper space and a lower space for permitting deformation of the rubber arm; a first mounting hole disposed in a center of the rubber arm in a vehicle left-right direction to extend in a vehicle front-back direction when installed on the vehicle, and attached in a mated condition to a support pin provided on one of a muffler side and a vehicle body side; and a pair of second mounting holes disposed at locations away to right and left sides from the first mounting hole to extend in the front-back direction, and attached in a mated condition to support pins on the other side. The first and second mounting holes are arranged to form a row in the left-right direction, with positional relationships such that when installed on the vehicle the holes overlaps one another as viewed in the left-right direction.

Abstract: A system for dampening the vibrations experienced by a sensing line connected to a jet pump within a nuclear reactor pressure vessel. The system may include an eccentric clamp assembly (ECA). The ECA includes: a cam member and saddle; a key member, such as a t-bolt; an eccentric member; a clamp member; clamp body. A jacking bolt, washers, and an ECA connector lock the assembly in place. The ECA allows for adjustment in multiple directions, reducing installation time.

Abstract: A sound suppression method includes using a passive noise suppression technology to destructively interfere with a sound wave propagating through a structure at portions of the structure that are positioned apart less than half of a wavelength of the sound wave.

Abstract: The present invention relates to an absorbent covering having high damping power, the covering being secured to a structure (20) and being provided with an absorbent layer (10) of elastic material (4). Remarkably, said absorbent layer (10) comprises a dissipater mesh arranged in the elastic material (4) and constituted by a plurality of nodes (2) and of dissipater elements (1), which dissipater elements are advantageously elliptical in shape.

Abstract: In one embodiment of the invention, a composition for a damping wedge in an ultrasonic probe having a wedge body is disclosed, the composition comprising: a viscoelastic material having a ratio of the imaginary part to the real part of the modulus of elasticity of at least about 5% and an acoustic impedance less than that of the wedge body; a filament-shaped filler in an effective amount to provide good dispersability in the viscoelastic material and to substantially match the acoustic impedance of the damping wedge to the wedge body; and a viscosity enhancer in an effective amount to increase the viscosity of the composition to maintain a homogenous distribution of the filament-shaped filler by preventing the filament-shaped filler from settling.

Abstract: An apparatus and method is provided for attenuating aerospace engine noise and unsteady pressure fluctuations associated with high velocity exhaust flows. The apparatus and method reduce acoustic fatigue damage to aerospace vehicles that may be caused by the reflection of exhaust energy from landing and/or launch platforms. The apparatus includes a passive treatment area associated with the platform operable for reducing the magnitude of the reflected sound waves and unsteady pressure fluctuations from the high velocity exhaust mass flow exiting from the engine. The passive treatment area may include a layer of sound absorptive material, at least one set of roughness elements for disrupting high velocity flow structures. A protective cover may be positioned over the passive treatment area for permitting exhaust flow to pass therethrough while still providing adequate structure to support the weight of the aerospace vehicle.

Abstract: A coupling device is interposed between an electronic or electro-acoustic component and a supporting structure for draining, transmitting and dissipating vibratory energy generated within the component, while isolating the component from vibratory energy emanating from the support structure, utilizing a ball rolling along a bearing surface in directions away from and toward an equilibrium position, with the ball biased toward the equilibrium position by magnetic attraction forces.

Abstract: A system and method is provided for dampening sound transmission and vibration for controlling noise in finished strata materials to which sound dampening channel members are attached. The system comprises a metal connector member including a base portion and at least one gripping portion joined to, and extending outwardly from, the base portion, for receiving and fixedly holding in place the metal sound dampening channel member on a structural support member. The metal sound dampening channel member being connectable to the gripping portion of the metal connector member and forming a gap therebetween without introducing energy transfer material in the gap thereby providing space for energy to dissipate throughout the gap and without creating any substantial hot spots.

Abstract: A sound absorbing element, in one example, includes a first wall area, a second wall area as well as a plurality of spring elements. In this arrangement, the first wall area and the second wall area are arranged so as to be spaced apart by a clear space. In one example, the plurality of spring elements are arranged in the clear space and connect the first wall area and the second wall area to each other. By pre-tensioning the plurality of spring elements to a state in which their spring constant approaches zero, significant decoupling between the first and the second wall areas may occur, with accompanying sound noise reduction.

Abstract: A plurality of openings are provided on the surface of a body casing which comprises a noise reduction chamber, and plate members (a reflecting plate and a sound waves introduction plate) are provided extending from an edge of each opening to the noise reduction chamber. The opening edges at which these plate members are attached have acute corners or rounded corners.

Abstract: An acoustic damping material for electro-optic material has an adhesive material combined with a ceramic crystalline material such that the acoustic impedance of the combined adhesive material and the ceramic crystalline material is substantially the same as the acoustic impedance of the electro-optic material.

Abstract: There is a noise reduction device for reducing noise from a vibrating strap. There is a securing member including a strip of material having a first surface including hook material and a second surface including loop material, wherein the securing member is configured to removably attach to the vibrating strap by wrapping about the strap and attaching a portion of the first surface to a portion of the second surface. There is a damping member including a plurality of strands of fibers configured to dampen vibratory motion. There is an internal coupling member configured to couple the securing member to the damping member and configured to bundle the plurality of strands of fibers.

Abstract: A squeeze film damper reduces acoustic wave transmission by the damping and spring forces produced by squeezing a very thin layer of air trapped between two vibrating plates. The damping effect is most pronounced when the gap between vibrating plates is very small, e.g., of the order of micrometers, thus, the squeeze film dampers have two, very closely-spaced opposing plates, the top of which vibrates out-of-phase with respect to the lower plate, when the lower plate is attached to a vibrating surface. The relative motion of plates squeezes out the thin film of air trapped within the plates and adds substantial amount of passive damping over a wideband of frequency to the base vibrating structure thereby reducing vibrations and noise radiated by the structure. The out-of-phase displacement of the top plate, with respect to the bottom plate, tends to cancel acoustic energy imparted to the lower plate by a vibrating surface. Squeeze film dampers can be applied in arrays to a vibrating surface.

Abstract: An energy attenuation device for a fluid-conveying line, and a method for attenuating energy in such a line, are provided. The device includes one or more hose sections disposed in the fluid-conveying line, and at least one spring disposed in at least a portion of each of the hose sections.

Abstract: The active/passive absorber for extended vibration and sound radiation control includes principally two layers. The first layer has a low stiffness per unit area which allows motion in the direction perpendicular to its main plane. The second layer is principally a mass layer. These two combined layers have a frequency of resonance close to one of the main structure. The dynamic behavior of the coupled system makes the active/passive absorber a passive absorber; however, the first layer can be electrically actuated to induce motion in the direction perpendicular to its main plane. This addition property induces and/or changes the motion of the mass layer and therefore improves the dynamic properties of the active/passive absorber system. The acive/passive absorber can have multiple mass layers and multiple elastic layers stacked one on top of the other. In addition, the mass layers can be continuous or discretized, and have varying thicknesses and shapes for sections and/or segments in the mass layer.

Abstract: A speaker box is covered with a buffer material exclusive of a portion where an acoustic output is derived from a speaker unit. The speaker box covered with the buffer material is attached to the surface of a wall member such as an interior member of a vehicle body or a side plate outside the vehicle body in a manner the speaker box is pressed by a holding member, which is a part of the interior member or designed member, and secured by bolts. Even when the surface of the speaker box is vibrated, the buffer material prevents an acoustic output due to the vibration from being generated so that no unnecessary acoustic signal is generated.

Abstract: A shock wave source has a coil carrier, a coil, having a metallic membrane separated from the coil in insulating fashion for generating shock waves. The coil carrier is formed of a material that damps the formation and/or the propagation of audible acoustic waves in the generation of shock waves.