Active control of acoustic radiation from laminated cylindrical shells integrated with a piezoelectric layer

Abstract

Active control of sound radiation from piezoelectric laminated cylindrical shells is theoretically investigated in the wavenumber domain. The governing equations of the smart cylindrical shells are derived by using first-order shear deformation theory. The smart layer is divided into lots of actuator patches, each of which is coated with two very thin electrodes at its inner and outer surfaces. Proportional derivative negative feedback control is applied to the actuator patches and the stiffness of the controlled layer is derived in the wavenumber domain. The equivalent driving forces and moments generated by the piezoelectric layer can produce distinct sound radiation. Large actuator patches cause strong wavenumber conversion and fluctuation of the far-field sound pressure, and do not make any contribution to sound reduction. Nevertheless, suitable small actuator patches induce weak wavenumber conversion and play an important role in the suppression of vibration and acoustic power. The derivative gain of the active control can effectively suppress sound radiation from smart cylindrical shells. The effects of small proportional gain on the sound field can be neglected, but large proportional gain has a great impact on the acoustic radiation of cylindrical shells. The influence of different piezoelectric materials on the acoustic power is described in the numerical results.

Integrated Topology Optimization of Structure/Vibration Control for Piezoelectric Cylindrical Shell Based on the Genetic Algorithm

“…Shell structure usually has more DOF and more complicated structural characteristic and mechanical behavior than truss and plate structure. For simplification, we utilized the four-node rectangular flat shell element with 24 displacement degrees of freedom (DOF) and 2 electrical DOF to build the piezoelectric coupling dynamic model of cylindrical shell structure [3,8]. The ideal element is shown in Figure 1.…”

“…where q is denoted by node displacement vector of the piezoelectric coupling flat shell element, and the meanings of the other symbols are similar to the utilizations of these in the literature [3,9]. By reducing the and terms in (8)-(10), the piezoelectric coupling finite element equation is obtained as follows:…”

“…However, the vibrations of those structures under complex and extreme dynamic loads are inevitable, as they are excited by strong wind and wave. So it is also necessary to design control system to suppress the amplitude of vibration for those structures in engineering practice [2,3].…”

Active control of cylindrical shells using the weighted sum of spatial gradients control metric

“…In other work by Shen and Wen, active control of a cylindrical shell was implemented by applying different control methods, such as inverted displacement, velocity and accelerationfeedback control strategies [47]. At the same time, another active control approach was presented by Cao and Shi, using actuator patches and negative feedback control for a piezoelectric laminated cylindrical shell [48]. In 2014, Ma and Jin applied active structural control to a cylindrical shell, combined with a passive vibration isolation system [49].…”

Active Transient Sound Radiation Control from a Smart Piezocomposite Hollow Cylinder

“…Just recently, Kwak and Yang (2013) both theoretically and experimentally investigated active vibration and sound radiation control of a ring-stiffened baffled circular cylindrical shell subjected to harmonic disturbance by means of piezoelectric sensor and actuator pairs. Cao et al (2013) subsequently investigated active (proportional derivative negative feedback) control of sound radiation from laminated cylindrical shells integrated with a segmented piezoelectric actuator layer in the wavenumber domain, based on the first-order shear deformation theory. Kim et al (2013) used finite element and experimental modeling to investigate active vibration and structure-borne noise suppression of an underwater cylindrical shell structure based on an optimal (LQG) control algorithm in conjunction with Macro Fiber Composites (MFCs) as actuators and sensors.…”