Vibration Control Of Composite Plates Research Articles

Active vibration control of composite plate with optimal placement of piezoelectric patches

ABSTRACTThe active vibration control of a composite plate using discrete piezoelectric patches has been investigated. Based on first order shear deformation theory, a finite element model with the contributions of piezoelectric sensor and actuator patches to the mass and stiffness of the plate was used to derive the state space equation. A global optimization based on LQR performance is developed to find the optimal location of the piezoelectric patches. Genetic algorithm is adopted and implemented to evaluate the optimal configuration. The piezoelectric actuator provides a damping effect on the composite plate by means of LQR control algorithm. A correlation between the patches number and the closed loop damping coefficient is established.

Active vibration control of CNT-reinforced composite plates with piezoelectric layers based on Reddy’s higher-order shear deformation theory

To date, the literature investigating the active vibration control of carbon nanotube reinforced composite (CNTRC) plates with piezoelectric layers is limited. Furthermore, studying this particular problem utilizing any of the element-free methods is missing. This paper presents a novel element-free IMLS-Ritz model based on Reddy’s higher-order shear deformation theory to study this issue. Four carbon nanotubes (CNTs) distributions are considered including both uniform and functionally graded types. For all these distributions, the effective material properties of the CNTRC plates are calculated by the Mori–Tanaka method. A conversion study has been performed to select the appropriate values of nodes number and scaling factor that give accurate results compared to the literature. New detailed natural frequency results have been presented for various CNTs volume fractions, CNTs distribution types, dimensions ratios and boundary conditions. Parametric studies have been carried out to show the effects of boundary conditions, CNTs volume fraction, CNTs distribution type and piezoelectric layer thickness to total plate thickness ratio on the natural frequency increment between open and closed circuit conditions. A constant velocity feedback approach is adopted for the active vibration control of the composite plates and two positions of piezoelectric sensor and actuator layers are proposed.

Experimental research on vibration control of composite plate with piezoelectric networks

Experimental research on vibration control of composite plate with piezoelectric networks

Shape memory elastic foundation and supports for passive vibration control of composite plates

The paper presents an approach to passive vibration control of shear deformable and thin plates. The first of two methods of vibration control employs prestressed shape memory alloy (SMA) wires embedded in sleeves attached to the surface of the plate. The spacing between the wires can be arbitrary and variable enabling the development of a SMA support system for maximum control with minimum additional weight. The other method considered in the paper utilizes SMA wires supporting the plate at strategically selected points. The mechanism of passive control includes two components: (1) SMA wires prestressed as a result of constrained phase transformation act as an elastic foundation with a variable stiffness and (2) energy dissipation occurs as a result of hysteresis in superelastic wires vibrating together with the structure. As follows from examples, it is possible to achieve a significant reduction of the vibration amplitude over a broad spectrum of driving frequencies using any of two methods considered in the paper.

Thermally induced vibration control of composite plates and shells with piezoelectric activedamping

A coupled piezoelectric field is modelled with an expansion strain in the numericalformulation to analyse piezohygrothermoelastic laminated plates and shells. Finite elementactuator and sensor equations are derived using a nine-noded field consistent shallow shellelement. Thermally induced vibration control is attempted using piezoelectricallydeveloped active damping. The influence of piezoelectric anisotropy on active damping isevaluated, adopting a simple modelling technique. With 40% reduced actuation capabilityin the lateral direction, the directionally active lamina is observed to be equally efficient incontrolling the vibration. In general, the directionally active lamina is efficient ifthe primary actuation direction is oriented along the fibre direction or in thedirection of bending. The directional actuation appeared to be more effective inthe velocity feedback control for cantilevered plates and shells. However, in thesimply supported case, a balanced actuation effort is required to provide bettercontrollability, which can be achieved by tailoring the directional actuation. Theimportance of geometric curvature for the actuator performance is also highlighted.

Numerical simulation model of vibration responses of rectangular plates embedded with piezoelectric actuators

A numerical simulation model for random large amplitude vibration control of composite plate using piezoelectric material is presented. The H ∞ control design is employed to suppress the large amplitude vibrations of composites plates under random loading. The numerical simulation model is developed and based on the finite element method. The finite element governing equation includes fully coupled structural and electrical nodal degrees of freedom, and consider the von Karman large amplitude vibration. The modal reduction method using the structural modes is adopted to reduce the finite element equations into a set of modal equations with fewer degrees of freedom. The modal equations are then employed for controller design and time domain simulation. In the simulations without control, the value of the linear mode to the nonlinear deflection is quantified; and the minimum number of linear modes needed for accurate model is obtained. In the simulations with control, it is shown that the truncated modes, which are neglected in the control design, deteriorate the controller performance. Generally, the vibration reduction level is not monotonically increasing with the size of the piezoelectric actuator. The optimal piezoelectric actuator size depends on the excitation level. For higher excitation level, optimal actuator size is larger. The H ∞ controller based on the linear finite element formulation gives better vibration reduction for small amplitude vibration, but it still gives reasonable performance for large amplitude vibration provided that the piezoelectric actuator is big and powerful enough.