Vibration Suppression Of Plate Research Articles

An Analytical Solution on Vibration Reduction and Shear Force Mitigation of Cantilever Mindlin Plates Using Orthogonal Ribs

Vibration of aircraft wings and the dynamic stress concentration at the clamped edge are important research topics due to concerns on the safety of aircrafts. To have a better understanding of the problem, the free and forced vibration response of a ribbed rectangular cantilever plate representing a section of an aircraft wing is investigated in this study. A new analytical solution is developed for the vibration analysis of rib stiffened cantilever plates using Mindlin plate and Timoshenko beam theories alongside the finite integral transform technique. The one- and two-dimensional integral transforms are applied to the governing equations of beams and plates, respectively, where the coupling force components at the interface between the base plate and the beam(s) can be automatically defined during the integral transform. Eventually, the partial differential equations are transformed into a system of linear algebraic equations in which its derivation is rigorous and easily implemented. Good agreements are found between the results of analytical solution, finite element analysis (FEA) and related literature. The solution is then employed to study the vibration suppression of cantilever plates and the shear force at the clamped edge. It is found that the insertion of a pair of orthogonal ribs in the plate can effectively reduce its vibration. An optimum orthogonal ribbing pattern is obtained using multi-objective particle swarm optimization (MOPSO) algorithm, taking into consideration both the vibration suppression of the plate and the maximum induced shear force at the corners of the clamped edge.

Control of a laminated composite plate resting on Pasternak’s foundations using magnetostrictive layers

A higher-order shear deformation theory is utilized to discuss the vibration of a laminated composite plate containing four magnetostrictive layers based on Pasternak’s foundations in the current article. Hamilton’s principle is used to derive the governing dynamic equations related to the vibration of present smart structure under velocity feedback control with constant gain distributed. Navier’s approach is utilized to give a solution of simply supported laminated composite plates. Effects of all material properties, modes, thickness ratio, aspect ratio, lamination schemes, magnitude of the feedback parameter, the elastic foundations parameters and the thickness, location and number of magnetostrictive layers, on the vibration damping characteristics of the system are investigated and extensively discussed. Findings of the damping coefficients, damped natural frequencies, damping ratio, vibration time and maximum deflection for some different laminates are computed. The influences of studied parameters on the vibration suppression of plates are illustrated graphically. The results indicate increasing of smart layers structures tends to more control of structure and elastic foundations can contribute the stability of the plate significantly.

Active Suppression of Plate Vibration Excited by Acoustic Pressure in a Chamber: Cluster-mode Approach

A cluster-mode control analysis of coupled structural and acoustic vibrations of a double-wall chamber system, which consists of four solid walls and elastic outer and inner plates placed opposite, as well as air occupying the chamber is presented in this article. The outer plate is externally driven to induce acoustic vibrations in the chamber, which consequently force the inner plate to oscillate. To understand complicated mechanical coupling of the structural and acoustic vibrations, the cluster-mode approach of filtering, sensing, and actuating is used. The coupled vibrations of the system are analytically grouped into four clusters in such a way that each clustered mode can be treated independently. As one may have a simpler view on the coupling in each cluster, it is easier to overview the coupled behaviors and control the oscillation of the system effectively. In numerical analysis, a feedforward control to the inner plate and a direct velocity feedback control (DVFBC) to the outer plate are applied. Numerical results show that the introduction of the cluster-mode filtering is useful in comprehending the complicated mechanical behavior of the coupled system. The hybrid use of optimum clustered feedforward control and clustered DVFBC has well suppressed the vibration of the internal plate.

Global control of a vibrating plate using a feedback-controlled inertial actuator

Strategies for the suppression of plate vibration are investigated by considering approximations to the equivalent impedance of power-minimizing vibration controllers. The total power transmitted to a plate by both a primary and a secondary point force is minimized and the equivalent impedance presented by the secondary source to the plate is considered. A novel device for active vibration control, based on an inertial actuator with displacement sensor and local PID controller and an outer velocity feedback control loop, is used to control the vibrating flexible plate. The impedance presented to the plate by this actuator is compared with the equivalent impedance of the optimal active control system. A frequency-domain formulation is used to analyse the stability and performance of an active vibration suppression system using this modified inertial actuator. The results of an experimental study of active vibration suppression on a flexible plate using the modified inertial actuator are then described. Theory and experiments agree well, demonstrating the effectiveness of the modified inertial actuator.