A vibration isolation system for a gas turbine engine. The vibration isolation system includes a first fixed structure and a second fixed structure separate from the first fixed structure. The vibration isolation system further includes a connector coupling the first fixed structure to the second fixed structure. Additionally, the vibration isolation system includes an isolator, including a shape memory alloy material, associated with the connector. The isolator is arranged between the first fixed structure and the second fixed structure such that the isolator reduces vibrations transferred between the first fixed structure and the second fixed structure.

A vibration isolating coupler including a first coupler portion, a second coupler portion including an external surface and an internal surface portion, and a vibration isolating portion extending between the first coupler portion and the second coupler portion. The vibration isolating portion including a first solid annular portion and a second solid annular portion. The vibration isolating portion including a plurality of slots extending from the first solid annular portion toward the second solid annular portion forming a plurality of vibration isolating elements. Each of the plurality of vibration isolating elements is disconnected from adjacent ones of the plurality of vibration isolating elements by a corresponding one of the plurality of slots. The plurality of vibration isolating elements enabling torsional rotation of the first coupler portion relative to the second coupler portion.

Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a downhole drilling system disposed at an end of the downhole system in operative connection with a drill bit. A damping system is installed on the downhole drilling system, the damping system having at least one damper element configured to dampen at least one HFTO mode. At least one mode-shape tuning element is arranged on the drilling system. The at least one mode-shape tuning element is configured and positioned on the drilling system to modify at least one of a shape of the HFTO mode, a frequency of the HFTO mode, an excitability of the HFTO mode, and a damping efficiency of the at least one damper element.

An apparatus for damping vibrations includes an inertial mass disposed in a cavity in a rotatable downhole component, the rotatable component configured to be disposed in a borehole in a subsurface formation, such as a resource bearing formation, the inertial mass coupled to a surface of the cavity by a damping fluid and configured to move within the cavity relative to the downhole component. The apparatus also includes a damping fluid disposed in the cavity between the inertial mass and an inner surface of the cavity, where rotational acceleration of the rotatable downhole component causes shear in the damping fluid to dissipate energy from rotational acceleration of the rotatable downhole component and causing the rotational acceleration to be reduced.

An apparatus for damping vibrations includes an inertial mass disposed in a cavity in a rotatable downhole component, the rotatable component configured to be disposed in a borehole in a subsurface formation, such as a resource bearing formation, the inertial mass coupled to a surface of the cavity by a damping fluid and configured to move within the cavity relative to the downhole component. The apparatus also includes a damping fluid disposed in the cavity between the inertial mass and an inner surface of the cavity, where rotational acceleration of the rotatable downhole component causes shear in the damping fluid to dissipate energy from rotational acceleration of the rotatable downhole component and causing the rotational acceleration to be reduced.

A fluid damper includes a cylinder tube portion which is filled with a fluid and a piston which is provided so as to be movable in an inner portion of the cylinder tube portion and whose moving speed is controlled with resistance of the fluid. Area of a flow path through which the fluid passes is changed with a temperature.

A fluid damper includes a cylinder tube portion which is filled with a fluid and a piston which is provided so as to be movable in an inner portion of the cylinder tube portion and whose moving speed is controlled with resistance of the fluid. Area of a flow path through which the fluid passes is changed with a temperature.

Provided herein is are multilayer damping laminates comprising alternating damping and constraining layers. The materials and configurations of the damping layers are selected such that the damping layers have a decreasing glass transition temperature profile beginning at the first damping layer, allowing the laminates to effectively dissipate vibrations over a wider range of operating temperatures and/or frequencies. Also provided are systems and methods using the multilayer damping laminates.

Provided herein is are multilayer damping laminates comprising alternating damping and constraining layers. The materials and configurations of the damping layers are selected such that the damping layers have a decreasing glass transition temperature profile beginning at the first damping layer, allowing the laminates to effectively dissipate vibrations over a wider range of operating temperatures and/or frequencies. Also provided are systems and methods using the multilayer damping laminates.

The present invention relates to, among other things, a rotational damper comprising a fluid-filled damper housing and within the damper housing a piston rotatably accommodated by a rotation axis of the rotational damper in a first direction and an opposite second direction with a piston rod extending in the direction of the rotation axis; whereby the piston has at least one opening with a flow cross-section which allows for the flow of fluid through the piston, whereby a total flow cross-section is calculated as the sum of the flow cross-sections of the at least one opening. A blocking device can be furthermore assigned to the piston which is capable of reducing the flow cross-section of at least one of the openings during a rotation of the piston in a first direction relative to a rotation of the piston in the second direction.