High authority piezoelectric torsional actuators

The results on the development of torsional actuators presented here are intended to demonstrate the basis for the utilization of novel, piezoelectric shear response, electromechanical actuators in smart materials and structures. The actuator design developed in this study is a segmented, piezoelectric tube, with the individual segments driven in a shear mode. The assembled tube can be driven to produce precise and significant angular displacement and high torque output directly from this solid state device. Techniques were developed for continuous poling, assembly and testing of actuators. Projected actuator outputs based on the electromechanical test results are discussed relative to the requirements of actual helicopter rotor blade applications, in terms of driving trailing edge flap and direct blade twist actuation.