Method for vibration damping of and vibration damper assembly for semi-submerged or submerged structure, based on separating hydrodynamic added mass from the semi-submerged or submerged structure by means of a vibration damper assembly exhibiting spring and/or damper properties and use the hydrodynamic added mass as a reaction mass in the vibration damper assembly.

Method for vibration damping of and vibration damper assembly for semi-submerged or submerged structure, based on separating hydrodynamic added mass from the semi-submerged or submerged structure by means of a vibration damper assembly exhibiting spring and/or damper properties and use the hydrodynamic added mass as a reaction mass in the vibration damper assembly.

A heat exchanger (HEX) for cooling air in a gas turbine engine is provided. An adjustable damper is provided. The adjustable damper may be for damping a movement of the HEX relative to the gas turbine engine. An adjustable damper may comprise: a first tube; a second tube located at least partially within the first tube; a housing coupled to the second tube; a moveable member, the moveable member comprising a contacting surface in contact with the second tube; an adjusting member adjustably coupled to the housing; and a spring member located between the moveable member and the adjusting member, the spring member configured to at least one of compress or decompress in response to adjusting member moving relative to the housing.

A sliding seismic isolation device includes a structure fixation plate having a first sliding surface and a metallic slider having a second sliding surface contacting the first sliding surface. A friction member composed of a single-layer fabric is attached to the first sliding surface, the second sliding surface, or both of the first sliding surface and the second sliding surface. One of a warp and a weft is formed of multiple plied yarns into which high-strength fibers and PTFE fibers are twisted together and the other of the warp and the weft is formed of multiple high-strength fibers in the single-layer fabric. The single-layer fabric has a twill weave and is woven such that the plied yarns of the one forming the single-layer fabric are exposed at a surface opposite from the attachment side of the friction member more than the high-strength fibers of the other forming the single-layer fabric.

A sliding seismic isolation device includes a structure fixation plate having a first sliding surface and a metallic slider having a second sliding surface contacting the first sliding surface. A friction member composed of a single-layer fabric is attached to the first sliding surface, the second sliding surface, or both of the first sliding surface and the second sliding surface. One of a warp and a weft is formed of multiple plied yarns into which high-strength fibers and PTFE fibers are twisted together and the other of the warp and the weft is formed of multiple high-strength fibers in the single-layer fabric. The single-layer fabric has a twill weave and is woven such that the plied yarns of the one forming the single-layer fabric are exposed at a surface opposite from the attachment side of the friction member more than the high-strength fibers of the other forming the single-layer fabric.

An exemplary shock absorber includes a damper tube, a damper piston, a piston shaft, and at least two different surface treatments. The damper tube includes an interior surface. The damper piston includes a piston surface that engages the interior surface. The piston shaft couples with the damper piston and includes a shaft surface that engages a fourth surface. The at least two different surface treatments are disposed on at least one of the interior surface and the shaft surface and create a corresponding plurality of coefficients of friction with at least one of the piston surface and the fourth surface respectively.

A damping system for a cable disposed within an upper pipe and a lower pipe includes a damper plate assembly connected to the upper pipe, a slider ring connected to and/or supported by the lower pipe, the slider ring having a hole in which the cable is arranged; and a shroud surrounding the damping system at a position where the upper pipe is adjacent to the lower pipe, such that the damper plate assembly and the slider ring are covered by the shroud. In such damping systems, the damper plate assembly and the slider ring are in contact with each other such that the transverse movement of the upper pipe relative to the lower pipe generates a frictional force to reduce an amplitude of the transverse movement of the upper pipe relative to the lower pipe.

A damping system for a cable disposed within an upper pipe and a lower pipe includes a damper plate assembly connected to the upper pipe, a slider ring connected to and/or supported by the lower pipe, the slider ring having a hole in which the cable is arranged; and a shroud surrounding the damping system at a position where the upper pipe is adjacent to the lower pipe, such that the damper plate assembly and the slider ring are covered by the shroud. In such damping systems, the damper plate assembly and the slider ring are in contact with each other such that the transverse movement of the upper pipe relative to the lower pipe generates a frictional force to reduce an amplitude of the transverse movement of the upper pipe relative to the lower pipe.

A helmet comprising first and second parts and a connector connecting the first and second parts of the helmet, the connector comprising: a first plate; a first anchor point on one side of the first plate, configured to be connected to the first part; a second plate located on an opposite side of the first plate from the first anchor point; a second anchor point on an opposite side of the second plate from the first plate, configured to be connected to the second part; a low friction interface provided between opposing surfaces of the first and second plates; and a cuff of deformable material provided around the first and second plates, and configured to at least partially cover the side of the first plate on which the first anchor point is located and to at least partially cover the side of the second plate on which the second anchor point is located.

A helmet comprising first and second parts and a connector connecting the first and second parts of the helmet, the connector comprising: a first plate; a first anchor point on one side of the first plate, configured to be connected to the first part; a second plate located on an opposite side of the first plate from the first anchor point; a second anchor point on an opposite side of the second plate from the first plate, configured to be connected to the second part; a low friction interface provided between opposing surfaces of the first and second plates; and a cuff of deformable material provided around the first and second plates, and configured to at least partially cover the side of the first plate on which the first anchor point is located and to at least partially cover the side of the second plate on which the second anchor point is located.