Vibration Suppression Of Structures Research Articles

Nonlinear Control System for Flat Plate Structures Considering Interference Based on Operator Theory and Optimization Method

In recent years, vibration control utilizing smart materials has garnered considerable attention. In this paper, we aim to achieve vibration suppression of a plate structure with a tail-fin shape by employing piezoelectric actuators—one of the smart materials. The plate structure is rigorously modeled based on the Kirchhoff–Love plate theory, while the piezoelectric actuators are formulated in accordance with the Prandtl–Ishlinskii model. This research proposed a control system that addresses the interference effects arising during vibration control by dividing multiple piezoelectric elements into two groups and implementing MIMO control. The efficacy of the proposed control method was validated through simulations and experiments.

Vibration Suppression and Energy Harvesting of Nonlinear Energy Sink-Based Piezoelectric System with Combined Damping and Bistability Properties for Nonlinear Oscillator

Nonlinear energy sink (NES) as a new type of dynamic absorber has received widespread attention due to its broadband vibration suppression capability, but it has a certain requirement of energy triggering threshold. In this work, a bistable NES-based piezoelectric system with combined damping (BCPNES) and low threshold requirement is proposed. Electromechanical-coupled equations for the nonlinear oscillator coupled with BCPNES (NO-BCPNES) are established. The vibration suppression and vibration energy harvesting performance for the coupled system are investigated numerically and analytically. The frequency–energy plots of the conservative system are investigated using the complex-variable averaging method and the electromechanical decoupling method. The influence of circuit parameters on the target energy transfer threshold and harvested energy is discussed through the equivalent stiffness and damping of the circuit. The vibration suppression performance and the target energy transfer characteristics are analyzed in terms of the time–history response, the time–frequency response and the slowly varying dynamic flow, respectively. The results show that the electromechanical coupling coefficient affects the skeleton curve of frequency–energy plots in the form of equivalent stiffness. The NO-BCPNES system exhibits higher energy dissipation performance and better targeted energy transfer form under various excitations. From the phase perspective, NES-based piezoelectric system achieves vibration suppression of the main structure through the phase locking phenomenon. The mechanism of the influence of piezoelectric device parameters on the energy harvesting performance of the systems is clarified.

Research on energy transfer and vibration suppression of nonlinear energy sink with nonlinear damping

The nonlinear energy sink is a nonlinear shock absorber that provides targeted energy transfer and plays a crucial role in structural vibration suppression. In this paper, the energy transfer and dynamic characteristics of nonlinear damping nonlinear energy sink systems are analyzed. Firstly, the theoretical model of the nonlinear damping NES system is described, and secondly, the equations of the system in the free state are derived by using the complex variable average method and the multi-scale method to obtain the energy transfer efficiency equation of the system. Through the study of the slow invariant manifold and energy transfer efficiency of the system, the influence of each system parameter on the energy transfer efficiency is analyzed. Then the equations of the system under harmonic excitation are processed in the same method to obtain the boundary equations of the system, through which the saddle-node bifurcation diagram of the system is plotted to study the influence of each system parameter on the saddle-node bifurcation characteristics of the system. Finally, the slow-varying equation of the system under harmonic excitation is derived, and the influence of each system parameter on the frequency detuning parameter interval of the strongly modulated response is obtained using the phase trajectory and a one-dimensional mapping diagram of the system, and the time-mileage diagram and Poincare section are used to prove the damping effect of the strongly modulated response.

Basic study of structural health monitoring for layered structures subjected to vibration from a semi-active dynamic vibration absorbers

Vibration suppression of structures and structural health monitoring (SHM) are important technologies for realizing a sustainable society, and as stated in SDGs No. 11 "Sustainable cities and communities,"their importance is widely known. Semi-active dynamic vibration absorbers (SADVA) are used in vibration suppression technology, in addition to passive and active dynamic vibration absorbers. Basically, the physical properties of SADVA, which are passive elements such as the spring constant and viscous damping coefficient, can be changed externally. These dynamic vibration absorbers generally operate only when an earthquake occurs. Here, to achieve SDG No. 12 "Responsible consumption, production," we verify whether it is possible to use some of the SADVA mentioned above for SHM. The vibration data of structures is sometimes used in SHM technology. Specifically, an abnormality is diagnosed by measuring the frequency response with a sensor installed in a structure and focusing on the change in the frequency response between normal and abnormal conditions. In this study, we propose a method to identify the location and level of abnormalities in layered structures using a part of SADVA as a shaker.

Active disturbance rejection control for piezoelectric cantilever beam with time delay

This Letter presents an active control method for the vibration of piezoelectric structures. First, a controller based on nonlinear extended state observer is designed to improve the disturbance rejection capability of the vibration structure. Additionally, an improved nonlinear active disturbance rejection control (IMNADRC) method is combined with Smith predictor for time delay compensation, resulting in Smith predictor-based IMNADRC. Finally, numerical simulations and experiments are carried out for active vibration suppression of piezoelectric beam under fixed harmonic excitation and variable harmonic excitation, respectively. The results show that the proposed method has good control effect on structural vibration suppression and is highly adaptable to various external excitations.

Vibration suppression of a cylindrical shell structure by transmission path control

Vibration suppression of a cylindrical shell structure by transmission path control

Embedded periodically ABHs and distributed DVAs for passive low-frequency broadband vibration attenuation in thin-walled structures

The acoustic black hole (ABH) structure exhibits remarkable energy focalization above a given cut-on frequency, offering potential for broadband vibration suppression in structures. However, its energy focusing properties diminish significantly below this cut-on frequency. Therefore, it is crucial to enhance the vibration attenuation capabilities of ABH structures within the low frequency range. This study presents a numerical investigation into the impact of thin-walled structures with embedded ABHs and distributed dynamic vibration absorbers (DVAs) on low frequency broadband vibration reduction. Initially, the focusing characteristics of the ABH thin-walled structure is analyzed, aiding in the attached position of DVAs. Furthermore, the influence of the design parameters and attached position of DVA on the broadband damping effect of the structure is explored. The findings indicate that DVAs designed for low frequencies can achieve significant vibration attenuation across the entire frequency spectrum, including low frequencies, when installed at specific focusing positions. When compared to the position with the maximum vibration response, while the attenuation of the low frequency common amplitude value is slightly reduced, greater vibration attenuation across the entire frequency band is achieved. This research offers valuable insights into optimizing the integration of DVAs with ABHs in thin-walled structures for enhanced broadband vibration attenuation.

Optimal design of fractional-order proportional integral derivative controllers for structural vibration suppression

In designing control systems, it is known that fractional-order proportional integral derivative (FOPID) controllers often provide greater flexibility than conventional proportional integral derivative (PID) controllers. This higher level of flexibility has proven to be extremely valuable for various applications such as vibration suppression in structural engineering. In this paper, we study the optimization of FOPID controllers using twelve well-established algorithms to minimize structural responses under seismic excitations. The algorithms include crystal structure algorithm (CryStAl), stochastic paint optimizer, particle swarm optimization, krill herd, harmony search, ant colony optimization, genetic algorithm, grey wolf optimizer, Harris hawks optimization, sparrow search algorithm, hippopotamus optimization algorithm, and duck swarm algorithm. In addition to highlighting the benefits of fractional calculus in structural control, this study provides a detailed analysis of FOPID controllers as well as a brief description of the algorithms used to optimize them. To evaluate the efficiency of the proposed techniques, two building models with different numbers of stories are examined. FOPID controllers are designed based on oustaloup’s approximation and the El Centro earthquake data. Using five well-known metrics, the performances of the developed methods are evaluated against five earthquake scenarios, including the recent earthquake in Turkey. A non-parametric (Friedman) test is also employed to compare the algorithms based on their corresponding vibration reduction. The findings of this analysis show that CryStAl consistently performs better than the other algorithms for both building models, thus resulting in superior vibration suppression.

Analyzing Vertical Earthquake Vibrations and Moving Vehicle Loads for Structural Health Monitoring and Vibration Suppression in Bridges

The design of bridges often overlooks the vertical component of earthquakes or considers it of secondary importance, despite compelling evidence indicating specific structural damage caused by primary earthquake waves. Conversely, during the operational phase, the combined influence of ground motion and moving loads from vehicles can significantly impact the structural health monitoring (SHM) of bridges. This study aims to evaluate the simultaneous effect of vertical earthquake vibrations and moving vehicle loads on simply supported bridges. The research employs a practical methodology based on the eigenfunction expansion method to analyze change of deflection due to the effect of these concurrent forces under seven different earthquake records. It is shown that within a realistic range of vehicle mass and velocity, the average of changing the maximum deflection at the mid-span of the main beam (denoted as M_n) reaches up to 163% under various scenarios. Subsequently, the seismic parameters influencing this phenomenon are identified through a statistical analysis of set of 100 different earthquake records with unique features. A linear regression equation is presented to predict the M_n based on the earthquake specific properties. Additionally, to control the vertical vibration of bridge systems, a novel vibration suppression system utilizing steel pipe dampers is introduced, and its reliability is examined across a broad spectrum of bridge flexural rigidity. The results indicate that the system's efficiency depends on M_n and the soil type of the bridge construction, enabling a reduction in structural sections (up to 27%) while achieving the same maximum target deflection in the initial state. This efficiency leads to a more economical design solution, emphasizing the potential benefits of the proposed system for practical application.

Vibration responses of vertical coupling plates considering elastic boundary and flexible joint connection using traveling wave approach

Complex structures are usually assembled by basic structure components, such as beams, plates, with different boundaries. It is necessary to study the vibration responses of coupling structures considering the connection effects between plates, which is the basis for structural vibration suppression and high-precision control of complex structures. In this work, the vibration responses of vertical coupling finite-length plates considering elastic boundary and flexible joint connection are investigated using numerical methodology. First, the theoretical model of the vertical coupling plates is established using the traveling wave method, in which the plate boundary is considered as elastic support, and the connection between vertical coupling plates is considered as flexible connection joint. The mathematical model of flexible connection between vertical coupling plates as well as the elastic boundary is introduced by using equivalent spring-damper model. Then, the influence of boundary conditions, connection conditions and excitation on the vibration responses are investigated by different case studies. The numerical simulation results indicate that boundary conditions, connection conditions and excitation have significant effects on the vibration responses of the vertical coupling plates. This investigation provides a theoretical basis for vibration response predication and vibration suppression and high-precision control of complex structures, which plays important theoretical significance and engineering application prospect.

Controllable Trade-Off Between Performance and Constrained Input for Vibration Suppression in Flexible Space Structures

Controllable Trade-Off Between Performance and Constrained Input for Vibration Suppression in Flexible Space Structures

Vibration energy transfer in forced laminated composite box structure

This study investigates the dynamics of laminated composite box structures from the viewpoint of energy flow transmission. Using a substructure-based technique, the power flow and dynamic responses are defined and obtained. The relationship between natural frequencies and the fiber orientations is explored. The influence of excitation frequencies, fiber angles, and boundary conditions on power flow and energy transmission paths (ETPs) is examined. The fiber orientations of box structure and boundary conditions are shown to have a substantial impact on ETPs and the positions of sinks. By modifying fiber angles, vibration suppression of box structure can be achieved.

Design of distributed dynamic absorbers for vibration suppression of panel structures

Design of distributed dynamic absorbers for vibration suppression of panel structures

Column-based programmable damper for impact protection and vibration suppression of jacket structures

Steel jacket structures subjected to environmental impacts exhibit severe dynamic responses, potentially causing local fatigue failure, plastic damage, and even catastrophic collapse. Therefore, a structure with adjustable stiffness and large damping is ideal for coping with complex environmental loads and dissipating kinetic energy. A novel programmable damper was designed by connecting N-layer coupling elements composed of a linear spring, wire ropes, and an asymmetric column. Analytical models for the elastic buckling behavior of the damper were derived and mutually verified with finite element analysis (FEA). Based on the analytical models, the dependence of the mechanical responses of the damper on the number of elements and the spring stiffness was investigated for design guidance. The results indicate that the N-layer damper has 2N different stiffnesses, and the total dissipation capacity increases by approximately 2.6N times compared with a single asymmetric column. For potential applications, the dynamic decay responses of representative jacket structures assembled with the damper were simulated using the FE software ABAQUS combined with user-defined-material (UMAT) code, which demonstrated that the programmable damper is an advanced device that simultaneously achieves adjustable stiffness and significant damping.

Advances in suppression of structural vibration and sound radiation by flexural wave manipulation

The newly generated artificial structures, including phononic crystals, elastic metamaterials, acoustic black holes (ABHs) and elastic metasurfaces, can abnormally control wave propagations. In this paper, focusing on plate structures and from the perspective of the suppression of vibration and especially sound radiation by manipulating flexural waves, we give a thorough review of the advances of above-mentioned artificial structures, involving their extraordinary characteristics, corresponding mechanisms of vibration and sound radiation suppression, design methods of phase-gradient elastic metasurfaces, and some representative works on suppressing vibration and sound radiation of plates by flexural wave manipulations. Additionally, we compare the advantages and disadvantages of these artificial structures in vibration and sound radiation suppression. Finally, we look forward to the prospects on vibration and sound radiation suppression of plates based on wave manipulations. This paper will provide a timely and practical assistance to academic and technical researchers in the field of vibration and noise reduction.

A meta-plate with radial rainbow reflection effect for broadband suppression of vibration and sound radiation

The suppression of vibration and sound radiation of thin plates has always been a concern in engineering fields such as aerospace, transportation, etc. The rainbow effect refers to that the waves with different frequencies can be stopped in different positions, where the wave energy is also enhanced, as the result of the spatial slowing-down of wave velocities. This effect exhibits great potential in suppressing structural vibration and sound radiation, but corresponding studies have not been reported yet. In this paper, a meta-plate composed of ring-type unit-cells with gradient heights is proposed to generate the radial rainbow reflection effect. Upon analyzing the dispersion relationship of unit-cells and revealing the rainbow reflection mechanism, the broadband vibration and sound radiation performances of a square meta-plate with free boundaries are studied. Numerical and experimental results demonstrate that the proposed meta-plate can suppress the vibration and sound radiation in broadband only with the extreme-low structural inherent loss. The wavenumber spectra of vibration velocity and supersonic intensity at typical frequencies including local and global resonant ones are analyzed to reveal the suppression mechanism of sound radiation, which is the vibration redistribution and systematic vibration reduction resulting from the rainbow reflection effect. Our design enhances the stiffness of plate structures and requires no additional damping, providing a novel approach for structural vibration and sound radiation suppression.

Vibration control of piezoelectric beams with active constrained layer damping treatment using LADRC algorithm

Active constrained layer damping (ACLD) treatment has become an important smart structure for vibration suppression due to its ability to achieve enhanced damping effects through real-time control. The control algorithm is a critical factor that determines the damping performance of the ACLD treatment. In this work, we utilize the linear active disturbance rejection control (LADRC) algorithm for the first time in the vibration suppression of beams with the ACLD treatment by compensating for the disturbance. To optimize vibration suppression, we also propose an efficient parameter tuning approach by analyzing the effects of controller bandwidth, control gain, and observer bandwidth on vibration suppression performance. Firstly, the dynamic model of elastic beams with the ACLD treatment is established and the LADRC algorithm is designed. Subsequently, the accuracy of the model is verified by comparing it with open literature and experiments. Then, the influences of the control parameters and different positions of the ACLD treatment on the vibration suppression performance are studied. Finally, the vibration suppression effects of LADRC and traditional PID algorithms are compared. The results indicate that the vibration suppression performance of the ACLD treatment is better than that of the passive constrained layer damping (PCLD) treatment. Setting the controller bandwidth to a small value and then adjusting other control parameters can effectively reduce the difficulty of parameter tuning while achieving superior vibration suppression performance. Appropriately increasing the observer bandwidth or reducing the control gain is beneficial for enhancing the suppression efficiency. The parameter tuning approach in this study provides vital guidance for the application of the LADRC algorithm in structural vibration suppression.

Vibration Suppression of Piecewise-Linear Stiffness Nes System Under Random Excitation

Nonlinear energy sinks (NESs) are critically important for structural vibration suppression. They can absorb vibrational energy across a broad frequency spectrum, possess strong robustness, and have a relatively small mass. This study addresses the vibration suppression in a piecewise linear stiffness NES system under random excitation. Initially, a theoretical model of the piecewise linear stiffness NES system is developed. The piecewise linear stiffness function is approximated using Legendre polynomial approximation. Following this, the steady-state Fokker–Planck–Kolmogorov (FPK) equation of the system is formulated via the Generalized Harmonic Function Method. The FPK equation is solved using the fourth-order central difference method, and the effectiveness of this approach is validated by comparing the FDM results with numerical simulations. Lastly, the influence of varying system parameters on the stability of the piecewise linear stiffness NES system is analyzed.

Vibration Control of Reinjection Pump Room Pipeline System Based on Dynamic Characteristic Analysis

The reinjection pump room plays a crucial role in industries such as petroleum and chemical engineering. Its main responsibility is to safely and effectively inject treated wastewater, exhaust gas, or other fluid substances into the formation, aiming to achieve resource recycling and environmental protection. However, the pipeline system of the reinjection pump room usually has complex spatial distribution, long span, and multi-point elastic support characteristics, which may cause structural vibration during operation, and have adverse effects on the stable operation, safety, and surrounding environment of the equipment. Therefore, in the pipeline design stage, it is crucial to conduct in-depth vibration analysis of complex pipeline systems to ensure that harmful resonance phenomena do not occur in the pipeline under working conditions. Given the potential impact of pipeline system vibration on equipment performance and surrounding environment, effective suppression of pipeline system structural vibration is of great practical significance. This article focuses on the vibration control strategy of the reinjection pump room pipeline system based on dynamic characteristic analysis. By conducting in-depth research on the dynamic characteristics of pipeline systems, including vibration frequency, modal analysis, and vibration transmission paths, the aim is to propose a set of targeted vibration control measures.

Quasi-periodic sonic black hole with low-frequency acoustic and elastic bandgaps

Metamaterials with the capability to control wave propagation in fluid or solid mediums have attracted plenty of fundamental scientific and engineering research in recent decades. This paper proposes a novel metamaterial, named Quasi-periodic sonic black hole (Q-SBH), to achieve both acoustic bandgap and elastic bandgap. The Q-SHB consists of two functional units: outer soft shells and inner stiff rings. The stiff rings with decaying inner radii are connected by soft shells, and the distances between rings take linear variation. The Q-SBH reserves the slow-sound effect of sonic black hole and the non-uniformly distributed rings serve as mistuning vibration absorbers. On the basis of these characteristics, broadband low-frequency acoustic and elastic bandgaps are generated simultaneously. We demonstrate the attenuation performance of the Q-SBH by theoretical, numerical and experimental methods. Parametric analysis and multi-objective optimization of the structure are carried out. The results demonstrate the great potential of the proposed Q-SBH in a broad range of physical fields requiring both air-borne noise reduction and structural vibration suppression.