Hydraulic damper with load regulation as a function of frequency by means of hydraulic inertia composed of a cylinder, comprising an inner chamber, a rod, a main piston and an inertia piston, immersed in a hydraulic fluid, so that the inner chamber is divided into 3 sub-chambers, the main piston comprises a flow path controlled by valves to allow bidirectional flow of fluid between the sub-chambers and the inertia piston comprises a flow path called the inertia channel configured to allow fluid flow between sub-cameras at both sides of the inertia piston.

An exemplary inventive subordinate oscillator array (SOA) includes two or more vibration attenuation devices (oscillators) that are sequentially arranged (e.g., via beams in the SOA) so that their respective anti-vibratory influences overlap. To design the SOA, an optimal number N of oscillators is calculated according to the equation N=ηQΔ, where η is the modal overlap, Q is the quality factor, and Δ is the desired fractional bandwidth. Each oscillator is akin to a conventional dynamic vibration absorber (DVA) and is characterized by its own mass, stiffness, damping, and geometry (e.g., length, width, and height). The respective characteristics of the oscillators are selected and the oscillators are distributed so that the SOA, when suitably attached to a vibrative structure, attenuates the vibrations of the structure so as to approximately flatten the structure's vibrations over a frequency band of interest.

An exemplary inventive subordinate oscillator array (SOA) includes two or more vibration attenuation devices (oscillators) that are sequentially arranged (e.g., via beams in the SOA) so that their respective anti-vibratory influences overlap. To design the SOA, an optimal number N of oscillators is calculated according to the equation N=ηQΔ, where η is the modal overlap, Q is the quality factor, and Δ is the desired fractional bandwidth. Each oscillator is akin to a conventional dynamic vibration absorber (DVA) and is characterized by its own mass, stiffness, damping, and geometry (e.g., length, width, and height). The respective characteristics of the oscillators are selected and the oscillators are distributed so that the SOA, when suitably attached to a vibrative structure, attenuates the vibrations of the structure so as to approximately flatten the structure's vibrations over a frequency band of interest.

An arrangement reduces oscillation of an oscillatory structure. The arrangement has: a structure having at least one mode in at least one direction; and an oscillation-reducing device. The oscillation-reducing device includes a housing on the structure; a cavity; and a body. The body is configured to make impact contact with a first surface portion and a second surface portion of an inner wall of the housing and disposed is in the cavity such that the body can make impact contact with the first surface portion and the second surface portion of the inner wall of the housing at least temporarily for as long as the structure is excited in the at least one mode in the at least one direction. The first surface portion or the second surface portion of the inner wall of the housing has a curved profile.

A vibration damping apparatus configured to damp a vibration of a target member includes a mass body, a base disposed on the target member, a support member disposed on the base and configured to support the mass body, a housing disposed on the base so as to surround the support member, an elastic member disposed so as to form a space in the housing and configured to apply a force to the support member, and a control unit configured to control a pressure of a fluid in the space by supplying the fluid to the space based on a vibration state of the target member.

An aircraft, has an airframe, a transmission, and a liquid inertia vibration elimination (LIVE) system disposed between the airframe and the transmission via spherical bearings of two legs and via a central spherical bearing.

A reaction compensation device includes a drive mechanism driving a first movable part with respect to a base, a reaction mass drive mechanism driving a second movable part with respect to the base; and a first relative position sensor measuring a relative position between the first movable part and the base. There is also a second relative position sensor measuring a relative position between the second movable part and the base, a first control system controlling the drive mechanism by taking in a signal outputted from the first relative position sensor as a feedback signal in response to a command value, and a second control system correcting the command value using a correction parameter for adjusting a difference between mass properties of the drive mechanism and reaction mass drive mechanism and for controlling the reaction mass drive mechanism.

A method of assembling a tower section of a wind turbine tower is provided. The method includes arranging the tower section of the wind turbine tower in a horizontal orientation; transporting a damper unit to a position inside the tower section while the tower section is arranged in the horizontal orientation; and mounting the damper unit to the tower section, wherein the damper unit is configured to damp motions of the wind turbine tower. Further, a horizontal transport system is provided that is supported at least at one position by the tower section and that includes a movable part configured to support a damper unit and to transport the damper unit in a horizontal direction from a position adjacent to an end of the tower section to a position at or adjacent to a mounting position of the damper unit inside the tower section.

In some examples, an oscillatory pumping system comprises: one or more active piston, a fluid, and two motors. The one or more active piston is disposed in a channel fluidically coupling two fluid chambers. The passive piston has a frequency response operable to counteract a vibratory displacement. The fluid is disposed in the channel and the two fluid chambers. The two motors couple to the one or more active piston. The two motors are operable to selectively change the frequency response of the passive piston based on oscillating the one or more active piston.

The present invention provides a method and apparatus for energy absorption and vibrational dampening when attached to a vertical or horizontal structure. According to a first preferred embodiment, the present invention includes a closed housing which may preferably include an internal, curved surface. According to a further preferred embodiment, the present invention may include at least one dampening weight or sphere which may preferably be disposed within the closed housing. According to a further preferred embodiment, the dampening sphere may include internal baffling such as particles having resistance to the flow of the particles within the closed housing.