Vibration Control Of Thin Plates Research Articles

Independent modal variable structure fuzzy active vibration control of thin plates laminated with photostrictive actuators

Photostrictive actuators can produce photodeformation strains under illumination of ultraviolet lights. They can realize non-contact micro-actuation and vibration control for elastic plate structures. Considering the switching actuation and nonlinear dynamic characteristics of photostrictive actuators, a variable structure fuzzy active control scheme is presented to control the light intensity applied to the actuators. Firstly, independent modal vibration control equations of photoelectric laminated plates are established based on modal analysis techniques. Then, the optimal light switching function is derived to increase the range of sliding modal area, and the light intensity self-adjusting fuzzy active controller is designed. Meanwhile, a continuous function is applied to replace a sign function to reduce the variable structure control (VSC) chattering. Finally, numerical simulation is carried out, and simulation results indicate that the proposed control strategy provides better performance and control effect to plate actuation and control than velocity feedback control, and suppresses vibration effectively.

Vibrations of plates with superelastic shape memory alloy wires

The article illustrates an approach to the passive vibration control of thin plates utilizing prestressed superelastic shape memory alloy (SMA) wires. The SMA wires can freely slide within protective sleeves that are either embedded within the structure or bonded to its surface. The vibration control mechanism combines an effective continuous elastic foundation representing the support provided by SMA wires to the structure with the energy dissipation as a result of the hysteresis occurring in the wires. The other approach to the vibration control employs superelastic wires attached to the structure at discrete points. The mathematical formulation of the problem presented in the article can be adopted for a rigorous computational analysis. In particular, a closed form expression is obtained for the loss factor in large aspect ratio plates supported at the midspan by a system of parallel SMA wires. As follows from numerical examples presented for such plates, the proposed method offers a significant damping, far exceeding that observed in conventional engineering structures.

Complete flexural vibration band gaps in membrane-like lattice structures

The propagation of flexural vibration in the periodical membrane-like lattice structure is studied. The band structure calculated with the plane wave expansion method indicates the existence of complete gaps. The frequency response function of a finite periodic structure is simulated with finite element method. Frequency ranges with vibration attenuation are in good agreement with the gaps found in the band structure. Much larger attenuations are found in the complete gaps comparing to those directional ones. The existence of complete flexural vibration gaps in such a lattice structure provides a new idea for vibration control of thin plates.

Theory and experimental investigaion of flexural wave propagation in thin rectangular plate with periodic structure

With the idea of the phononic crystals, a thin rectangular plate with two-dimensional periodic structure is designed. Flexural wave band structures of such a plate with infinite structure are calculated with the plane-wave expansion (PWE) method, and directional band gaps are found in the ΓX direction. The acceleration frequency response in the ΓX direction of such a plate with finite structure is simulated with the finite element method and verified with a vibration experiment. The frequency ranges of sharp drops in the calculated and measured acceleration frequency response curves are in basic agreement with those in the band structures. Thin plate is a widely used component in the engineering structures. The existence of band gaps in such periodic structures gives a new idea in vibration control of thin plates.

Active control of adaptive laminated structures with bonded piezoelectric sensors and actuators

A finite element formulation for active vibration control of thin plate laminated structures with integrated piezoelectric layers, acting as sensors and actuators, is presented in this paper. The finite element model is a nonconforming single-layer triangular plate/shell element with 18 degrees of freedom for the generalized displacements and one electrical potential degree of freedom for each piezoelectric element layer. The model is based on the Kirchhoff classical laminated theory, and can be applied to plate and shell adaptive structures. To achieve a mechanism of active control of the structure dynamic response, a feedback control algorithm is used, coupling the sensor and active piezoelectric layers, and the Newmark method is considered to calculate the dynamic response of the laminated structures. The model is applied in the solution of four illustrative cases, and the results are presented and discussed.

Distributed transducer vibration control of thin plates

This paper presents an energy‐based analysis of the application of distributed, biaxial piezoelectric transducers for the vibration measurement and control of thin plates, subject to general boundary conditions. The method exploits plate modal symmetry and boundary integral representations of key parameters to choose spatial weightings for distributed sensors and actuators. The technique may be used to develop transducer spatial distributions and temporal compensators to simultaneously measure and damp multiple plate modes, as well as target selected modes. Sensor and actuator distributions facilitating all‐mode measurement and control are developed for various boundary conditions. For the purposes of illustration, models based on the piezoelectric polymer film transducer polyvinylidene fluoride (PVF2) are used.