Pan et al. reported a theoretical analysis of the active control of low-frequency radiated pressure from submarine hulls [9,10]. However, most of these works were limited to surface-bonded piezoelectric ceramic patches. Piezoelectric ceramic patches are very brittle, and not easy to use for curved geometry. To solve this problem, a Macro Fiber Composite (MFC) actuator, based on a sheet of rectangular piezoelectric ceramic fiber, was developed at the NASA Langley Research Center [11,12]. The MFC actuator is flexible, and therefore applicable to curved structures. In-plane poling with d33 property can be achieved by an interdigitated electrode, which produces more induced actuating strain than possible with a monolithic piezoelectric ceramic patch.
Azzouz et al.
investigated finite element modeling of an MFC actuator [13], and Sodano et al. studied applications of MFC actuators in structural vibration control [14]. Choi et al. presented active vibration control of pre-twisted rotating composite thin-walled beam with MFC actuators [15]. They used a negative velocity feedback control algorithm to suppress a pre-twisted rotating blade. Dano and Julliere reported the use of MFC actuators to control thermally induced deformations in laminated composite structures [16]. Barkanov et al. investigated the active twist control of a helicopter rotor blade using an MFC actuator to reduce vibration and noise, without any complex mechanism in the rotating systems [17]. Binette et al.
studied the shape control of composite structures using MFC actuators [18].
They used MFC actuators to compensate for thermally-induced distortion of a sandwich plate subjected to a through-the-thickness thermal gradient. Vadiraja Carfilzomib Batimastat and Sahasrabudhe proposed the structural modeling of a rotating pre-twisted composite beam with embedded MFC actuators and sensors, using higher shear deformation theory [19,20]. They used a LQG control algorithm to reduce the structural vibrations of the box beam. Bilgen et al. demonstrated a variable camber airfoil using MFC actuators [21,22]. Sohn et al. reported active vibration control of a smart hull structure using MFC actuators [23,24].
All of these works involve active vibration/noise control of smart structures using MFC actuators in air conditions. Zhang et al. investigated underwater sound radiation control of a stiffened plate structure by the active vibration isolation technique [25], and evaluated their scheme experimentally [26]. Caresta reported the active control of sound radiation of a submarine hull structure in theoretical bending vibration [27]. Experimental research on the active vibration control of underwater structure is rare.