DESIGN AND EXPERIMENTAL VERIFICATION OF THE COMPOSITE BLADE OF THE MAIN ROTOR OF AN UNMANNED HELICOPTER

The increasing use of unmanned aerial vehicles (UAVs) across various industries worldwide dictates new design rules and standards for their structures and systems. The reliability and durability of these structures are achieved through the application of advanced materials. Each structure must be designed in accordance with mission requirements to withstand the necessary aerodynamic and mechanical loads. The development of an unmanned helicopter presents a significant engineering challenge, particularly in the design of the main rotor, which requires a multidisciplinary approach and the coupling of aerodynamic, aeroelastic, and structural phenomena. This helicopter has a maximum takeoff weight of 750 kg, classifying it as a light helicopter. This research presents a comprehensive approach to the design, numerical analysis, and experimental validation of a composite helicopter rotor blade, in accordance with predefined operational requirements. The key specifications include maintaining an identical geometry compared to an existing model, precisely defining the blade mass at 11.5 kg, utilizing composite materials, and ensuring that the blade root can withstand an axial load of 40 tons. Additionally, aerodynamic efficiency is optimized by maintaining the LOCK number within the range of 5–7. The blade design is based on composite prepreg materials due to their high specific strength, excellent fatigue resistance, and superior damage tolerance. The structural configuration has been developed to achieve an optimal balance of weight, strength, and aerodynamic performance.