Jinqiang Li

Vibration suppression for laminated cylindrical panels with arbitrary edge conditions

Active vibration control of laminated cylindrical panels with arbitrary edge condition is investigated using piezoelectric fiber reinforced composite (PFRC) material. The boundary cases considered are free edge, simply supported edge and clamped edge for thin panels. Adopting a velocity feedback control strategy the transient response of cylindrical panels can be suppressed efficiently, and the relationship between the control gain and active damping ratio has been investigated. The active damping ratio curves are numerically calculated, and from the simulation results it is also found that the piezoelectric fiber orientation of the PFRC patches plays an important role in the vibration suppression capability.

The effect of aspect ratios and edge conditions on the optimal damping design of thin soft core sandwich plates and beams

An optimal design is presented to maximize the fundamental damping loss factor of sandwich rectangle plates and beams with general boundary conditions. With an extensive development of the classical laminate theory and energy method, the loss factor of sandwich laminate with a thin viscoelastic core is deduced. For sandwich-laminated plates and beams, the effect of fiber orientation of the orthotropic layer on the loss factor has been studied. The aspect ratio is very important in structural design for plates and beams. In this work, the effects of aspect ratios of sandwich laminates on optimal fundamental loss factors are investigated. The maximum fundamental loss factor and optimal fiber orientation have been obtained and analyzed for different sandwich laminates with the aspect ratio as a variable.

Reduction of wind-induced vibration of a laminated plate with an active constrained layer

An active control method is proposed to reduce the wind-induced vibration of laminated plates by use of a velocity feedback control strategy. A piezoelectric fiber-reinforced composite sensor and actuator are used to achieve effective active damping in the vibration control. The displacements in the time and frequency domains, as well as the power spectral density and the mean-squared value of the transverse response, are formulated under wind pressure at variable control gain. It is observed in the numerical results that the damping performance of the laminated plate can be significantly improved by using an outside active voltage on the constraining layer. The effects of the fiber orientation angles, both in the base laminated plate and the active piezoelectric fiber-reinforced composite constrained layer, are also discussed.

Random Vibration Control of Laminated Composite Plates with Piezoelectric Fiber Reinforced Composites

This paper presents an analysis of the active control of random vibration for laminated composite plates using piezoelectric fiber reinforced composites (PFRC). With Hamilton’s principle and the Rayleigh-Ritz method, the equation of motion for the resulting electromechanical coupling system is derived. A velocity feedback control rule is employed to obtain an effective active damping in the suppression of random vibration. The power spectral density and mean-square displacements of the random vibration for laminated plates under different control gains are simulated and the validity of the present control strategy is confirmed. The effect of piezoelectric fiber orientation in the PFRC layer on the random vibration suppression is also investigated. The analytical methodology can be expanded to other kinds of random vibration.

Vibration suppression for laminated composite plates with arbitrary boundary conditions

An analysis of vibration suppression for laminated composite plates subject to active constrained layer damping under various boundary conditions is presented. Piezoelectric-fiber-reinforced composites (PFRCs) are used as active actuators, and the effect of PFRC patches on vibration control is reported here. An analytical approach is expanded to analyze the vibration of laminated composites with arbitrary boundary conditions. By using Hamilton’s principle and the Rayleigh–Ritz method, the equation of motion for the resulting electromechanical coupling system is derived. A velocity feedback control rule is employed to obtain an effective active damping in the vibration control. The orientation effect of piezoelectric fibers in the PFRC patches on the suppression of forced vibrations is also investigated.