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

The accurate prediction of rotor and dynamic component load/stress remains an elusive goal. Despite major advancements in computational fluid dynamics (CFD) techniques, prediction of the unsteady aerodynamic loads acting on the blades continues to be a formidable computational task. The accuracy of these predictions remains problematic. Accordingly, Techno-Sciences, Inc. (TSi), in collaboration with the Alfred Gessow Rotorcraft Center at the University of Maryland (UMD), proposes to develop an Advanced Rotorcraft Load Prediction (ARLP) tool for rotor and dynamic components that features combined analytical and experimental approaches. During the Phase I effort, we have focused on prediction correlations with Blackhawk flight test data in level flight and maneuvering flight modes, for which we have obtained very good correlation results to date. Further performance gains will be achieved in Phase II as the ARLP system is refined and extended. Sensor measurements (strain, acceleration, loads, etc.) will be used to derive airloads and constantly improve analytical load predictions to yield a combined analytical/experimental predictive tool. At the conclusion of the Phase II program, we will be able to use the ARLP to expertly predict the load/stress of the rotor and dynamic components that will benefit the Navy structural health and usage monitoring (SHUM) program for fault and fatigue analyses.