Latest Developments in Fluidlastic® Lead-Lag Dampers for Vibration Control in Helicopters

An idea in the 80’s, in production in the 90’s, Fluidlastic® lead-lag dampers have seen wide acceptance in the marketplace. An initial production application on the Bell 430, has been followed by a production application on the NHI NH-90, and prototype applications for the Sikorsky Black Hawk, Bell H-1, Boeing-Sikorsky RAH-66 Comanche, and Agusta A-109. Fluidlastic® lead-lag dampers combine the high reliability of elastomeric dampers with improved damping performance. Fluid is contained in chambers within bonded elastomeric elements that accommodate relative motion. Motion in the lead-lag direction drives the fluid through a restriction to produce the required damping. Initial designs have achieved damping stiffness (K”) values of 1.3 times the elastic stiffness (K’) value. Loss factors achieved by the latest generation of Fluidlastic® dampers are much greater. Fluidlastic® damper designs can exceed the performance characteristics of either viscous plate shear type dampers or hydraulic dampers. Rotor designers can take advantage of this improved Fluidlastic® damper performance in their latest technology rotors and rotor upgrades.