Influence of elastomeric damper modeling on the dynamic response of helicopter rotors

Several modeling approaches that describe the behavior of elastomeric materials used in helicopter rotor lag dampers are examined and evaluated, rising laboratory test data. Two of the models are then used in a simulation of a helicopter rotor startup, and the simulation results are compared to one another and to flight test data. The models created using laboratory test results show that the simple, complex modulus model will yield good predictions of damper energy dissipation, but the simulation results indicate that this model is inadequate for predicting forced response. Although some of the models evaluated performed better than the others, none were free from limitations that would make them unsuitable for some applications. It is recommended that more effort be put into acquiring and analyzing damper test data to facilitate the development of more robust modeling approaches.