Combined Analytical and Experimental Approaches to Rotor and Dynamic Component Stress Predictions

The objective of this proposal is to combine analytical modeling and experimental data to dramatically improve the accuracy of predictions for individual blade loads and stresses in dynamic components. The overall proposed approach can be summarized as follows: 1) a number of strain measurements are made on rotorcraft blades during flight; 2) these measurements are used to identify the aerodynamic loads applied to the blade (or identification of strains at critical locations, directly) using simplified models of the blade dynamic behavior, such as reduced order models; 3) the identified airloads (or strains) are used to predict stresses at critical locations in the blade and dynamic components using a comprehensive structural dynamic model of the rotor; and 4) the proposed procedure is validated by performing well-controlled laboratory experiments.