A study of the Active Structural Acoustic Control (ASAC) of a full scale deHavilland Dash-8 series 100 fuselage is presented in this paper. Piezoceramic elements bonded on the fuselage were used for structural actuation. Using two separate approaches to error sensing, twelve accelerometers were used in one case whereas three microphones were employed in the second approach. Multi-Input and Multi-Output (MIMO) feedforward control was carried out using the filtered-x Least Mean Square (LMS) adaptive algorithm. The propeller acoustic field on the port side of the aircraft was simulated using a sound source consisting of four loud-speakers. The operating deflection shapes (ODS) for the fuselage in the vicinity of the propeller plane were measured. Based on these measurements, the placement of piezoelectric actuator was optimized and experimentally verified. The vibration and noise control strategy was implemented on the full scale aircraft with the objective of reducing the noise and vibration levels at the propeller Blade Passage Frequency (BPF) and its harmonics. The effectiveness of the control was demonstrated by achieving reductions as high as 21.6 dB in the fuselage vibration and 25.8 dB in interior sound field.

Proceedings of the 1998 39th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference and Exhibit and AIAA/ASME/AHS Adaptive Structures Forum. Part 1 (of 4)
Carleton University

Xu, W., Afagh, F, Grewal, A., & Zimcik, D. (1998). Effects of segmented piezoelectric actuator configuration on aircraft noise control performance. In Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference (pp. 2257–2264).