An Examination of Selected Problems in Rotor Blade Structural Mechanics and Dynamics

The deformation of rotorcraft blades are frequently classified as moderate, exceeding the small deformation limitation of typical beam finite elements. Advances in computer capabilities have made possible an implementation of a hybrid element combining rigid and flexible body kinematics in the Rotorcraft Comprehensive Analysis System (RCAS). Two challenges to new software are to verify the correctness of the implementation and to ascertain whether it represents an improvement. Comparisons are made to analytical results, to measurements from the “Princeton Beam” and Maryland vacuum chamber experiments, and to UH-60 flight test data. Inspection of these comparisons lead to the conclusion that the results obtained with RCAS correlate well with analytical and experimental results, sometimes representing significant improvements.