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The Rotational Tension Element Damper (RTED) uses a controlled tension line, backed by hydraulics, to damp large displacements in large structures. NASA built RTED prototypes that have been successfully tested on a 170-foot long wind turbine blade in test beds at the University of Maine. In this case, the RTED device damps the vibration of the large, tall turbine blades relative to a stationary anchor structure on the ground using a line and spring coupled to both the blade and the anchor, and controlled by a spool fitted with a one-way clutch. When force is applied, from heavy wind for example, the resulting movement of the tall structure triggers the necessary tension and compression cycles in the system to engage the rotating damper. The reaction force interferes with the rotation speed of the spool and disrupts and damps the vibration in the tall structure. The figure below shows test data for the RTED used on the wind turbine.

When waves move a floating wind turbine, they drive fluid motion inside the MTLCD. This forces air in the vertical tanks through an orifice, increasing pressure much like a spring. As the air discharges, the fluid’s motion is damped and energy is dissipated. The MTLCD also incorporates added damping elements, such as an orifice or variable-aperture reciprocating reed valve, that create resistance to air flow, further controlling fluid motion and dissipating energy. By integrating these modifications, the MTLCD is easily tuned to the platform’s motions, reducing dependency on platform geometry. Eliminating damping elements from the fluid removes the need for marine-grade hardware, reducing system costs. The MTLCD can also be integrated into existing ballast tanks, maximizing space efficiency with minimal added parts. While initially developed for NASA’s Floating Wind Turbine Development project, this invention can support vibration mitigation applications across multiple industries, such as infrastructure, maritime systems, and aerospace. By enabling precise tuning of dynamic response characteristics, the MTLCD offers a compact solution for platforms requiring vibration suppression. The technology has completed preliminary design and simulation, is at a TRL 3 (proof-of-concept), and is available for patent licensing.