High Fidelity Helicopter Lag Damper Model for Comprehensive Rotor Analysis

This research is dedicated to developing high fidelity lag damper models to significantly improve the accuracy of the analysis of the rotor lead-lag damper forces over a wide range of blade lead-lag motion amplitudes, temperatures, and frequencies in support of aircraft design and engineering applications. The model development will emphasize the dampers with various configurations (e.g., linear stroke and snubber) and various materials (e.g., elastomeric materials, fluidic materials, and various combinations of these two materials). Semi-active dampers with feedback control will also be modeled. The developed damper model will be suited for modern comprehensive rotorcraft analysis systems formulated using multi-body and finite element methodology. In Phase~I of this SBIR, ART will team with Penn State University and the work will focus on the development of the time domain elastomeric damper, the time domain fluid-elastomeric damper, and the magnetorheological fluid-elastomeric damper. The Phase~I efforts will also focus on integration of the lag damper models in a comprehensive rotorcraft analysis system. In addition, Phase~I will demonstrate the feasibility, accuracy, and capability of the models via stability and loads analyses of a rotorcraft in both ground resonance and forward flight.