Abstract: A tuned mass damper (TMD) system in combination with a floating offshore wind turbine (FOWT) platform includes a barge type FOWT platform having a hull configured to have a wind turbine tower mounted thereon. A TMD system is mounted in the hull and has a first TMD configured to operate at a first frequency, and a second TMD configured to operate at a second frequency different than the first frequency.

Abstract: A motion stabilizing system includes at least one stabilizer coupled to a structure in a water environment. Each stabilizer includes a tension member, an open-ended container having a set of holes, and at least one one-way valve associated with the holes. For each stabilizer, the tension member has a first end and a second end with the first end coupled to a portion of the structure and the second end disposed in the water environment; the container is coupled to the tension member and is suspended in the water environment; and the one or more one-way valves are operable to seal the holes when the portion of the structure moves away from the container and unseal the holes when the portion of the structure moves towards the container.

Abstract: A motion stabilizing system includes at least one stabilizer coupled to a structure in a water environment. Each stabilizer includes a tension member, an open-ended container having a set of holes, and at least one one-way valve associated with the holes. For each stabilizer, the tension member has a first end and a second end with the first end coupled to a portion of the structure and the second end disposed in the water environment; the container is coupled to the tension member and is suspended in the water environment; and the one or more one-way valves are operable to seal the holes when the portion of the structure moves away from the container and unseal the holes when the portion of the structure moves towards the container.

Abstract: A motion damper for structures includes a housing coupled to a structure such that the housing moves in correspondence with the structure. The housing includes a wall with a vent, and has an air chamber therein in fluid communication with the vent. A piston is sealed within the housing for one-dimensional motion therein. A rigid plate is disposed within the housing's air chamber. The plate is disposed between the piston and the vent, and is spaced apart from and fixedly coupled to the piston such that the plate moves in correspondence with the one-dimensional motion of the piston. At least one spring is mounted in the housing and is coupled to the plate for applying a force thereto that is in opposition to the one-dimensional motion of the piston.

Abstract: A frequency-tunable vibration damper includes a first container having rigid wall regions and compliant wall regions. A second container is coupled to the first container such that a wall region of the second container includes one of the compliant wall regions. A fluid fills the first container and a gas fills the second container. A flow restrictor is included in the second container and is spaced-apart from the one of the compliant wall regions included with the second container.

Abstract: A motion damping system includes a tank compartmentalized to have a first compartment having a first opening, a second compartment having a second opening, and a third compartment disposed between the first and second compartments. The third compartment is in fluid communication with the first and second openings. A first piston is movably sealed within the first compartment and is in fluid communication with its first opening. A second piston is movably sealed within the second compartment and is in fluid communication with its second opening. A liquid fills the third compartment, a portion of the first compartment up to the first piston, and a portion of the second compartment up to the second piston. A coupling fixedly attached to the first and second pistons moves in correspondence with the first and second pistons. Motion damper(s) coupled to the coupling resist movements of the first and second pistons.

Abstract: A motion absorbing system and method for a structure includes the coupling of a container to a structure. The container has a liquid disposed therein wherein a ullage is defined above a surface of the liquid. An elastic element is positioned in the liquid. The elastic element has a natural frequency tuned to damp motion of the liquid.

Abstract: A unidirectional damping system includes a shaft and unidirectional damping modules. Each module is fixedly coupled to the shaft. Each module includes a fluid-filled variable-volume chamber and spring(s). The chamber has at least one port through which fluid flows based on changes in volume of the chamber wherein, when the shaft is adapted to have a unidirectional force applied thereto, the chamber decreases in volume. The spring(s) is coupled to the chamber for increasing volume of the chamber when the unidirectional force is not applied to the shaft. A fluid-filled spacer chamber is coupled between adjacent modules and is uncoupled from the shaft. The spacer chamber includes at least one venting port through which fluid flows based on pressure in the spacer chamber.

Abstract: A motion absorbing system and method for a structure includes the coupling of a container to a structure. The container has a liquid disposed therein wherein a ullage is defined above a surface of the liquid. An elastic element is positioned in the liquid. The elastic element has a natural frequency tuned to damp motion of the liquid.

Abstract: A damping system includes a spool about which a tension line is wound. The line's first end is coupled to a first structure subject to forces causing unwanted movement thereof. A damper is coupled to a second structure not subject to the unwanted movement of the first structure. The damper is coupled to the spool for engagement with the spool to slow a rotational speed thereof when the spool rotates in a first direction. The damper is disengaged from the spool when the spool rotates in a second direction in opposition to the first direction. A device, coupled to the line's second end and to the second structure, applies a tension force to the line's second end. The tension force is exceeded when the first structure moves to place the line in tension, and is not exceeded when the first structure moves to place the line in compression.

Abstract: A bi-directional damping system generates damping forces in two opposing directions. A shaft has a plurality of bi-directional damping modules fixedly coupled thereto. Each module includes a fluid-filled variable-volume first chamber including at least one port through which fluid can flow based on changes in volume of the first chamber, and a fluid-filled variable-volume second chamber including at least one port through which fluid can flow based on changes in volume of the second chamber. The first chamber and second chamber are fluidically isolated from one another. A fluid-filled spacer chamber is coupled to adjacent ones of the modules. The spacer chamber includes at least one venting port through which fluid can flow based on pressure in the spacer chamber.

Abstract: A frequency-tunable vibration damper includes a first container having rigid wall regions and compliant wall regions. A second container is coupled to the first container such that a wall region of the second container includes one of the compliant wall regions. A fluid fills the first container and a gas fills the second container. A flow restrictor is included in the second container and is spaced-apart from the one of the compliant wall regions included with the second container.

Abstract: A frequency-tunable vibration damper includes a first container having rigid wall regions and compliant wall regions. A second container is coupled to the first container such that a wall region of the second container includes one of the compliant wall regions. A liquid fills the first container and a gas fills the second container. A flow restrictor is included in the second container and is spaced-apart from the one of the compliant wall regions included with the second container.