Development of a piezoelectric actuator for trailing edge flap control of full scale rotor blades

The present paper covers the development of a piezoelectric actuator for trailing edge flap control on a 34 ft diameter helicopter main rotor. The design of an actuator using biaxial stack columns, and its bench, shake, and spin testing are described. Actuator bench testing proves the basic actuator concept, but also points to required performance improvements. Actuator robustness is demonstrated in shake and spin tests simulating the full range of dynamic conditions inside the rotor blade. A series of actuator improvements are implemented, resulting in almost doubled performance. Projections using the latest stack technology show that the improved actuator will meet the performance requirements. The next steps in this program are development of the actuator and full scale rotor system for whirl tower testing and flight testing on the MD Explorer.

Presented at SPIE's Symposium on Smart Structures and Materials, Paper Number 3668-104, Newport Beach, 1999.