Structural design of an active trailing-edge flap blade for helicopter vibration control

An active trailing-edge flap(ATF) blade was designed to reduce the vibratory loads and noise of the rotor by altering the unsteady aerodynamic environment. The proposed blade was required to rotate at higher RPM in order to match the tip Mach number and had additional structures to support the actuators and flap. The cross-section of the blade was designed first and structural integrity was verified using a geometrically exact 1-D beam analysis. In order to predict the effects on the structure due to additional components inside the blade, a detailed three dimensional analysis was carried out using the commercial finite element program MSC.NASTRAN. A suitable bench-top test bed was developed and used for validating the flap excitation by piezoelectric actuator.