Deformable Training Edges and Smart Material Actuation for Active Control of Rotor Blades.

This project will determine the feasibility of smart material actuation of deformable trailing edges for active control of helicopter rotor blades. Several concepts will be developed and analyzed. Innovative structural designs and use of materials will be considered. The proposed designs will be analyzed to predict their performance levels, fatigue strength, and impact on blade weight and balance. Evaluation will be based on the analysis plus factors such as cost, reliability, reparability, etc. Representative portions of a production helicopter blade section including a deformable trailing edge, flexural zones, elastomeric slip joints, and actuation devices will be fabricated. Manufacturing techniques will explore implementation of smart materials, processing of elastomers, and other unconventional uses of materials to make up the deformable trailing edge. Static performance will be measured and used to calibrate the analysis. These sample sections will help validate and discriminate between the different design approaches. They will also provide insight to producability, durability, and areas for improvement. Recommendations will be made for the most effective structural concept and use of actuation materials. If successful, a concept will be generated which has the potential to be developed into a flight article and tested. Follow-on development, i.e. phase II, will be used to fine tune the selected concepts and validate the predictions by testing rotor blade sections and wind tunnel models. BENEFITS: The technology developed may be applied to all existing and future civil or military rotorcraft for improvements in performance, reduction of vibration, and reduction of noise.