Alleviation of Buffet-Induced Vibration Using Piezoelectric Actuators

摘要

Buffet-induced vibration has been problematic for aircraft structures for many years. The F-16 ventral fin, while prone to these effects, lends itself well to the evaluation of modern active structural and flow control technologies. The objective of this research was to determine the most critical natural modes of vibration for the F-16 ventral fin and design piezoelectric actuators capable of reducing buffet-induced ventral fin vibration. A finite element model (FEM) for the fin was developed, tuned and optimized to closely match published modal frequencies. Piezoelectric actuator patches were designed using the strain characteristics of the FEM and integrated into the model using a thermal analogy which allowed voltage application and the resulting strain to be simulated by a change in temperature. Two phases of critical mode selection were completed and included reviews of existing flight test data, historical ventral fin failure characteristics, and the results of aeroelastic and closed-loop aeroservoelastic analyses conducted on the FEM. Results showed the FEM tuning and optimization procedures, as well as the design and implementation process for the piezoelectric actuators to be very effective. Modes 1, 2 and 4 were determined to be the most suitable for future application of the technology.