Vibration Suppression Of Structures Research Articles

Active vibration control of piezoelectric bonded smart structures using PID algorithm

Thin-walled structures are sensitive to vibrate under even very small disturbances. In order to design a suitable controller for vibration suppression of thin-walled smart structures, an electro-mechanically coupled finite element (FE) model of smart structures is developed based on first-order shear deformation (FOSD) hypothesis. Considering the vibrations generated by various disturbances, which include free and forced vibrations, a PID control is implemented to damp both the free and forced vibrations. Additionally, an LQR optimal control is applied for comparison. The implemented control strategies are validated by a piezoelectric layered smart plate under various excitations.

Application neural network controller and active mass damper in structural vibration suppression

With the trend toward taller and more flexible building structures, a mass-damper shaking table system has been considered as means for vibration suppression to external excitation and disturbances...

Fuzzy control optimized by a Multi-Objective Differential Evolution algorithm for vibration suppression of smart structures

Smart structures include elements of active, passive or hybrid control. The fuzzy control is considered which is a suitable tool for the systematic development of active control strategies. A new Multi-Objective Differential Evolution algorithm for the calculation of the free parameters in active control systems is proposed and tested. In particular, the usage of MODE with a combination of continuous and discrete variables for the optimal design of the controller is proposed. Numerical applications on smart piezoelastic beams are presented. The results obtained are compared with the ones obtained with the fuzzy controller optimized by a MOPSO algorithm.

Acoustic metamaterial plates for elastic wave absorption and structural vibration suppression

This article presents the design and modeling techniques and design guidelines, and reveals the actual working mechanism of acoustic metamaterial plates for elastic wave absorption and structural vibration suppression. Each of the studied metamaterial plates is designed by integrating two (or one) isotropic plates with distributed discrete mass-spring-damper subsystems that act as local vibration absorbers. For an infinite metamaterial plate, its stopband is obtained by dispersion analysis on an analytical unit cell. For a finite metamaterial plate with specific boundary conditions, frequency response analysis of its full-size finite-element model is performed to show its stopband behavior, and the stopband behavior is further confirmed by transient analysis based on direct numerical integration of the finite-element equations. Influences of the vibration absorbers׳ local resonant frequencies and damping ratios and the plate׳s damping, boundary conditions, and natural frequencies and mode shapes are thoroughly examined. The concepts of negative effective mass and spring and acoustic and optical wave modes are explained in detail. The working mechanism of acoustic metamaterial plates is revealed to be based on the concept of conventional vibration absorbers. An absorber׳s resonant vibration excited by the incoming elastic wave generates a concentrated inertial force to work against the plate׳s internal shear force, straighten the plate, and attenuate/stop the wave propagation. Numerical results show that the stopband׳s location is determined by the local resonant frequency of absorbers, the stopband׳s width increases with the (absorber mass)/(unit cell mass) ratio, and increase of absorbers׳ damping significantly increases the stopband׳s width and reduces low-frequency vibration amplitudes. However, too much damping may deactivate the stopband effect, and the plate׳s material damping is not as efficient as absorbers׳ damping for suppression of low-frequency vibrations.

Analysis of vibration suppression of master structure in nonlinear systems using nonlinear delayed absorber

In this paper, a nonlinear delayed absorber is proposed by a delayed feedback loop and is utilized to absorb or suppress the vibration of a two-degree-of-freedom nonlinear system when the primary resonance and the 1:1 internal resonance occur simultaneously. To explain analytically mechanism of performance of the absorber, an integral equation method is provided to obtain the second order approximation and the amplitude equations. As a result, the feedback gain and time delay which make the amplitude of the main system equal to zero can be derived analytically. Optimal working conditions of the system are extracted from the time delay-response curves, the force-response curves and the frequency-response curves. In the illustrative example, the appropriate choice of feedback gains and time delays can reduce the amplitude of the main system by more than $$98\,\%$$ in comparison with the amplitude with no time delay. All analytical predictions are in excellent agreement with the numerical simulations.

Vibration suppression of structure with electromagnetic shunt damping absorber

The electromagnetic shunt damping absorber (EMSDA) is developed based on electromagnetic shunt damping mechanism. The governing equation of planar vibration system equipped with the EMSDA is derived. An optimization method is presented to determine the main working parameters of EMSDA on the basis of the built theoretical model. The objective function minimizing the response variance of system under white noise excitation is formulated. The particle swarm optimization algorithm is employed in optimization. The simulated and experimental studies on vibration control by use of EMSDA are conducted. The results show that the electromagnetic shunt damping absorber can attenuate significantly the structural vibration.

Application neural network controller and active mass damper in structural vibration suppression

With the trend toward taller and more flexible building structures, a mass-damper shaking table system has been considered as means for vibration suppression to external excitation and disturbances in recent years. However, there are few researches on the control of nonlinear structure using active mass damper (AMD) under earthquake excitation, especially for high-rise building. In this work, a multilayer feedforward neural network with the modified Newton method, similar to BFGS algorithm, is developed for vibration suppression of a building structure. The benchmark tests show that the modified Newton method is superior to many conventional ones: steepest descent, steepest descent with adaptive learning rate, conjugate gradient, and Newton-based methods and is suitable to small network in engineering applications. Experimental results show that an AMD system combined with the modified Newton method remains effective for building structure vibration suppression under free vibration, forced vibration and Ji-Ji Earthquake (Sep. 21, 1999) excitation.

Vibration Suppression of a Large Beam Structure Using Tuned Mass Damper and Eddy Current Damping

For a few decades, various methods to suppress the vibrations of structures have been proposed and exploited. These include passive methods using constrained layer damping (CLD) and active methods using smart materials. However, applying these methods to large structures may not be practical because of weight, material, and actuator constraints. The objective of the present study is to propose and exploit an effective method to suppress the vibration of a large and heavy beam structure with a minimum increase in mass or volume of material. Traditional tuned mass dampers (TMD) are very effective for attenuating structural vibrations; however, they often add substantial mass. Eddy current damping is relatively simple and has excellent performance but is force limited. The proposed method is to apply relatively light-weight TMD to attenuate the vibration of a large beam structure and increase its performance by applying eddy current damping to a TMD. The results show that the present method is simple but effective in suppressing the vibration of a large beam structure without a substantial weight increase.

Dynamics and vibration suppression of space structures with control moment gyroscopes

This paper presents a new and effective approach for vibration suppression of large space structures. Collocated pairs of control moment gyroscope (CMG) and angular rate sensor are adopted as actuators/sensors. The equations of motion of a flexible structure with a set of arbitrarily distributed CMGs are developed. The detailed dynamics of the CMGs and their interactions between the flexibilities of the structure are incorporated in the formulation. Then, the equations of motion are linearized to describe the small-scale motion of the system. The optimal placement problem of the actuators/sensors on the flexible structures is solved from the perspective of system controllability and observability. The controller for the vibration suppression is synthesized using the angular rates of the locations where the CMGs are mounted and the gimbal angles of the CMGs. The stability of the controller is proved by the Lyapunov theorem. Numerical examples of a beam structure and a plate structure validate the efficacy of the proposed method.

Disturbance rejection control for vibration suppression of piezoelectric laminated thin-walled structures

Abstract Thin-walled piezoelectric integrated smart structures are easily excited to vibrate by unknown disturbances. In order to design and simulate a control strategy, firstly, an electro-mechanically coupled dynamic finite element (FE) model of smart structures is developed based on first-order shear deformation (FOSD) hypothesis. Linear piezoelectric constitutive equations and the assumption of constant electric field through the thickness are considered. Based on the dynamic FE model, a disturbance rejection (DR) control with proportional-integral (PI) observer using step functions as the fictitious model of disturbances is developed for vibration suppression of smart structures. In order to achieve a better dynamic behavior of the fictitious model of disturbances, the PI observer is extended to generalized proportional-integral (GPI) observer, in which sine or polynomial functions can be used to represent disturbances resulting in better dynamics. Therefore the disturbances can be estimated either by PI or GPI observer, and then the estimated signals are fed back to the controller. The DR control is validated by various kinds of unknown disturbances, and compared with linear-quadratic regulator (LQR) control. The results illustrate that the vibrations are better suppressed by the proposed DR control.

Using an inerter‐based device for structural vibration suppression

SUMMARYThis paper proposes the use of a novel type of passive vibration control system to reduce vibrations in civil engineering structures subject to base excitation. The new system is based on the inerter, a device that was initially developed for high‐performance suspensions in Formula 1 racing cars. The principal advantage of the inerter is that a high level of vibration isolation can be achieved with low amounts of added mass. This feature makes it an attractive potential alternative to traditional tuned mass dampers (TMDs). In this paper, the inerter system is modelled inside a multi‐storey building and is located on braces between adjacent storeys. Numerical results show that an excellent level of vibration reduction is achieved, potentially offering improvement over TMDs. The inerter‐based system is compared to a TMD system by using a range of base excitation inputs, including an earthquake signal, to demonstrate how the performance could potentially be improved by using an inerter instead of a TMD. Copyright © 2013 John Wiley & Sons, Ltd.

Analysis and active control for wind induced vibration of beam with ACLD patch

The structural vibration suppression with active constrained layer damping (ACLD) was widely studied recently. However, the literature seldom concerned with the vibration control on flow-induced vibration using active constrained layer. In this paper the wind induced vibration of cantilevered beam is analyzed and suppressed by using random theory together with a velocity feedback control strategy. The piezoelectric material and frequency dependent viscoelastic layer are used to achieve effective active damping in the vibration control. The transverse displacement and velocity in time and frequency domains, as well as the power spectral density and the mean-square value of the transverse displacement and velocity, are formulated under wind pressure at variable control gain. It is observed from the numerical results that the wind induced vibration can be significantly suppressed by using a small outside active voltage on the constrained layer.

HPSO Algorithm of Actuator Placement for Vibration Suppression of Large Flexible Space Structure

Optimal actuator placement is the key technology to be solved for active vibration suppression of large flexible space structure. According to the features of close mode and light damping, the optimal criterion derived from the controllability and observability of Grammian matrix is designed; Hybrid Particle Swarm Optimization (HPSO) algorithm is introduced to solve the problem in optimizing actuator placement, and the detail solving step is given. Compared with genetic algorithm (GA) in previous research, HPSO is better than GA in convergence rates and computing time. Based on the above optimal results, LQG/LTR control method is utilized when the large flexible structure under pulse and Gauss white noise excitation respectively. The numerical simulation results show that LQG/LTR, which has a better performance in suppressing structure vibration than LQG, can suppress the vibration of large flexible space structure and improve system robustness.

AMB Vibration Control for Structural Resonance of Double-Gimbal Control Moment Gyro With High-Speed Magnetically Suspended Rotor

This paper explores a robust μ-synthesis control scheme for structural resonance vibration suppression of high-speed rotor systems supported by active magnetic bearings (AMBs) in the magnetically suspended double-gimbal control moment gyro (MSDGCMG). The derivation of a nominal linearized model about an operating point was presented. Sine sweep test was conducted on each component of AMB control system to obtain parameter variations and high-frequency unmodeled dynamics, including the structural resonance modes. A fictitious uncertainty block was introduced to represent the performance requirements for the augmented system. Finally, D-K iteration procedure was employed to solve the robust μ-controller. Rotor run-up experiments on the originally developed MSDGCMG prototype show that the designed μ-controller has a good performance for vibration rejection of structural resonance mode with the excitation of coupling torques. Further investigations indicate that the proposed method can also ensure the robust stability and performance of high-speed rotor system subject to the reaction of a large gyro torque.

Development of a rule selection mechanism by using neuro-fuzzy methodology for structural vibration suppression

The development of neuro-fuzzy systems by integrating neural networks and fuzzy systems is desired because such systems can adjust fuzzy membership functions and produce fuzzy inference rules by case-learning without the need for experts or experiments. It has been applied to various fields, but there has been no detailed study of the various neuro-fuzzy models applicable to rule generation. In this paper, an experimentally verified five-layer and three-phase network is presented, which shows the effectiveness with which the neuro-fuzzy system automatically determines membership functions and selects activation fuzzy rules using both system identification and vibration control examples in engineering applications.

Passive damping of slender and light structures

This paper describes the design optimization and fabrication of a hybrid composite material for the passive suppression of flexural vibrations in slender and light structures. The material is made from glass fiber/epoxy resin laminated, reinforced with two thin, fiber-laser patterned sheets of NiTiCu shape memory alloy (SMA). The thickness of the SMA layers and their pattern geometry have been optimized by the numerical calculation of the first natural frequency and of the structural damping of the hybrid composite. In addition to describing the thermo-mechanical characterization of the SMA alloy, selected as a reinforcement, the paper also describes the final dynamic characterization of four, beam-shaped prototypes using the material in question.

Vibration suppression of a cantilever beam using magnetically tuned-mass-damper

Eddy currents are induced by the movement of a conductor through a stationary magnetic field or a time varying magnetic field through a stationary conductor. These currents circulate in the conductive material and are dissipated, causing a repulsive force between the magnet and the conductor. These electromagnetic forces can be used to suppress the vibrations of a flexible structure. A tuned mass damper is a device mounted in structures to reduce the amplitude of mechanical vibrations and is one of the effective vibration suppression methods. In the present study, an improved concept of this tuned mass damper for the vibration suppression of structures is introduced. This concept consists of the classical tuned mass damper and an eddy current damping. The important advantages of this magnetically tuned mass damper are that it is relatively simple to apply, it does not require any electronic devices and external power, and it is effective on the vibration suppression. The proposed concept is designed for a cantilever beam and the analytical studies on the eddy current damping and its effects on the vibration suppression. To show the effectiveness of the proposed concept and verify the eddy current damping model, experiments on a cantilever beam are performed. It is found that the proposed concept could significantly increase the damping effect of the tuned mass damper even if not adequately tuned.

Active vibration suppression in smart structures subjected to model uncertainties and environmental disturbances: an adaptive approach

This paper presents a novel adaptive-based vibration control algorithm for smart structures, despite the model parameter variations, unstructured uncertainties, and environmental disturbances. The rate of vibration suppression can be managed in the proposed method, by taking a desired exponential decaying trajectory. Since the proposed method is established by taking various perturbations into account, it can be applied to a wide class of structures without any conservative hypotheses. The stability analysis is presented based on the Lyapunov’s direct method. In order to verify the effectiveness of the method, numerical analyses are presented and discussed by applying the developed vibration control methodology to a smart beam.

Simulating Displacement and Velocity Signals by Piezoelectric Sensor in Vibration Control Applications

Intelligent structures with built-in piezoelectric sensor and actuator that can actively change their physical geometry and/or properties have been known preferable in vibration control. However, it is often arguable to determine if measurement of piezoelectric sensor is strain rate, displacement, or velocity signal. This paper presents a neural sensor design to simulate the sensor dynamics. An artificial neural network with error backpropagation algorithm is developed such that the embedded and attached piezoelectric sensor can faithfully measure the displacement and velocity without any signal conditioning circuitry. Experimental verification shows that the neural sensor is effective to vibration suppression of a smart structure by embedded sensor/actuator and a building structure by surface-attached piezoelectric sensor and active mass damper.

Suppression of random vibration in flexible structures using a hybrid vibration absorber

A design method is proposed to suppress stationary random vibration in flexible structures using a hybrid vibration absorber (HVA). While the traditional vibration absorber can damp down the vibration mainly at the pre-tuned mode of the primary structure, active damping is generated by the proposed HVA to damp down all resonant modes of interest of the vibrating structure and the spatial average mean square motion of the vibrating structure can be minimized. Only one absorber and one feedback signal are required to achieve global vibration suppression of a flexible structure under stationary random excitation. A special pole-placement controller is designed such that all vibration modes of the flexible structures become critically damped. It is proved analytically that the proposed HVA damps the vibration of the entire structure instead of just the attachment point of the absorber. The proposed optimized HVA is tested on a beam structure and it shows a superior performance on global suppression of broadband vibration in comparison to other published designs of passive and hybrid vibration absorbers.