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 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 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 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: An adjustable sealing device for a storage container is disclosed that has a compressible sealing ball to provide a seal with the inner surface of containers having a variety of sizes and shapes. The device's valve ball for its vent is normally biased closed by a tensioner, and is selectively opened by a flexible lead. The lead passes through a container lid and compression washer(s) located between the sealing ball and lid. To insert the sealing ball into the container the lead is tensioned, to orient the longitudinal axis of the washer(s) perpendicular to the lid and sealing ball, so that pressure on the lid will be transmitted to the sealing ball through the compression washer(s). Releasing the lead's tension enables the lid to be placed on the container, and the lead and compression washers to be compactly draped over the sealing ball inside of the container.