Vibration Suppression Of Structures Research Articles

Output feedback-based adaptive fuzzy sliding mode control for seismic response reduction of base-isolated buildings

In this research, a model-free control strategy for vibration suppression of base-isolated structures, which are excited by an earthquake, is investigated. For this purpose, the semi-active base isolated system including a magnetorheological (MR) damper is utilized. In this way, the displacement of the base isolator is measured by a linear variable differential transformer (LVDT). Accordingly, an adaptive fuzzy sliding mode observer is implemented to estimate the vector of state tracking error. This estimated vector is then employed by an adaptive fuzzy sliding mode control scheme to calculate the input voltage of the MR damper. The efficiency of the implemented model-free control strategy is studied by some numerical simulations. The advantages of the proposed controller can be summarized as its flexibility and robustness against disturbance rejection and model uncertainty.

A new time-domain robust anti-windup PID control scheme for vibration suppression of building structure

Robustness is one of the main issues in the design of closed-loop control systems, and to provide it, considering the differences between the actual and mathematical models, effects of external disturbances and measurement noise is necessary. In this study, a new time-domain robust anti-windup proportional integral derivative (PID) control scheme for vibration suppression of building structure is introduced. Because of computational complexity in determining and tuning gains of the controller for each structural vibration modes in the conventional PID control methods. Such as modal analysis; the dynamic vibration equations of the structure are implemented in the state space form to consider the effects of all vibration modes of the structural system in the controlling gains simultaneously. Uncertainties in the structural stiffness parameter, sensing noise, input time-delay, and saturation windup of the actuator are considered in a new formulation. To ensure robust stability and performance of the proposed controller, the closed-loop transfer function from exogenous inputs to the controlled outputs is defined as in the standard form of the H∞ mixed sensitivity minimization criterion. The PID control gains are obtained by minimizing the infinity norm of the closed-loop transfer function of the control system in standard form. Based on numerical study of an 11-story benchmark structure equipped with an active tuned mass damper, the robustness and stability of the proposed controller are presented. This controller can reduce further the maximum displacement, velocity, and acceleration of the structure subjected to far field earthquakes with considering uncertainties by 16, 10, and 16%, respectively, compared to the conventional PID controller.

Frequency attenuation band with low vibration transmission in a finite-size plate strip embedded with 2D acoustic black holes

Acoustic Black Hole (ABH) structures allowing for wave manipulation and energy focalization have potential applications in broadband structural vibration suppression. In this work, the vibration transmission characteristics of a plate strip embedded with multiple two-dimensional (2D) ABH without additional damping material were investigated. Both the simulation and experimental results show that the investigated structure exhibits attenuation bands with low vibration transmission, and the vibration attenuation phenomenon appears in frequency ranges well below the cut-on frequency of the ABHs. The width and position of the attenuation bands depend on the number of ABHs. A numerical investigation was carried out on the mechanism of the attenuation band generation. The analysis results show dual physical effects: low modal transmission in asymmetrical structures and modal displacement cancellation on the receiving side in both asymmetrical and symmetrical structures. Strong local structural resonances induced by ABHs play an important role in modal transmission reduction, modal displacement cancellation and weak excitation of some modes. The attenuation phenomenon reveals a new ABH-specific feature which enriches the existing knowledge on ABH structures and broadens the design perspective of vibration attenuation through band creation.

Alternative tuning method for proportional-derived gains for active vibration control in a building structure

The article deals with the development of active vibration control of seismically-excited building structures. The control scheme is based on an alternative proportional-derived (PD) controller designed based only on the bandwidth of the system, which is an attractive technique for structural vibration suppression purposes and practical motion control solutions. The tuning method is analyzed employing Kharitonov’s theorem and Routh-Hurwitz criteria, which give necessary and sufficient conditions for choosing the two PD range of gains. Based on modal analysis, the system is transformed into a set of decoupled ordinary differential equations to simplify the PD design. An important advantage concerning a classical PD controller is the proposed PD design only uses the natural frequencies, which are relatively easy to estimates around an experimental test. Moreover, the proposed approach does not need frequently tune the gains parameters, so the design procedure is greatly simplified and, the proposed scheme does not need the system parameters, which generally are unknown. This method allows generalizing the controller design for multi-story buildings without modifying the controller structure, by choosing a scalar parameter. The effectiveness of the proposed PD schemes is demonstrated through simulation and experimental results of a reduced scale two-story building prototype.

Analysis of the Vibration Suppression of Double-Beam System via Nonlinear Switching Piezoelectric Network

In this paper, a method to suppress the vibration of a double-beam system with nonlinear synchronized switch damping on the inductor via a network (SSDI-net) is proposed. Unlike the classical linear piezoelectric shunt damping, SSDI-net is a nonlinear piezoelectric damping. A double-beam system with SSDI-net was simplified to a lumped parameter electromechanical coupling model and analyzed by using the multi-harmonic balance method, at first with alternating frequency–time techniques (MHBM/AFT). Then, a new lower-power autonomous switching control circuit board was designed, based on SSD technique, and vibration control experiments using a double-beam system with an SSDI network are conducted, to verify the validity of the proposed analysis method and its calculation results. The nonlinear switching piezoelectric network proposed in this article can increase the voltage inversion factor. Furthermore, future applications of this switching piezoelectric network technology in the vibration suppression of bladed-disk structures in aero engines can reduce the number of switches by at least half and obtain almost the same damping effect.

High dynamic range and high dispersion stability of a magnetorheological grease damper for semi-active vibration suppression

In this study, the dynamic range and dispersion stability of a shear-type magnetorheological (MR) grease damper were experimentally investigated as important characteristics affecting the performance of semi-active vibration suppression. Furthermore, the damper was applied to the semi-active vibration suppression of a small single-degree-of-freedom model structure subjected to seismic excitation. The performance test results of the damper indicated that it has a dynamic range of 157 times, which is much higher than that of conventional MR dampers. Also, because of the high dispersion stability of MR grease, the results showed that its performance can be kept for 9 days longer in comparison with a similar damper using MR fluid. Moreover, the structural vibration suppression test results demonstrated that the damper can suppress vibration response over a wide frequency range by applying skyhook-based control, which can take full advantage of the damper’s high dynamic range.

Using an inerter to enhance an active-passive-combined vehicle suspension system

Performance of a passive vehicle suspension can be improved with the help of an active actuator, however, with potentially problematic control requirements, such as high energy consumption and large actuator forces. To maximize performance benefits without requiring significant control efforts, the passive and active parts need to be designed and work synergistically. In this paper, a novel combined passive and active vibration suppression approach of which the passive part is enhanced by an inerter is proposed for improving the trade-off between dynamic performance and control requirements. Via this approach, the optimal passive configuration consisting of inerter(s), spring(s) and damper(s) with pre-determined numbers and the optimal active control parameter can be identified. The approach is demonstrated using a case study where the combined suspension is designed considering a quarter-car model and a typical active controller (i.e., the skyhook control). It will be shown that, compared with a conventional passive part of a spring-damper, adding an inerter in parallel can significantly improve the pareto optimality between the ride comfort and power (or force) requirements. The improvement is further enhanced by systematically exploring all passive network possibilities with a pre-determined complexity via the structure-immittance technique. This approach is also applicable to the vibration suppression of other engineering structures.

Effect of viscoelastic properties of polymer and wavy shape of the CNTs on the vibrational behaviors of CNT/glass fiber/polymer plates

Carbon nanotube (CNT)-reinforced polymer nanocomposites possess marvelous stiffness and strength as well as viscoelastic nature due to the time-dependent properties of the polymers. Hence, adequate knowledge about their rheological behavior is required if it is aimed at using such nanomaterials in design of aerospace structures. Present manuscript is arranged to account for the time-dependency of the polymer as well as wavy shape of the CNTs while tracking the vibrational responses of multi-scale hybrid nanocomposites for the first time. To this purpose, a mixture of the modified Halpin–Tsai model and mixture’s rule is used for the homogenization process. According to the dynamic form of the virtual work’s principle, the governing equations of the problem will be attained based on a higher-order shear deformable plate theorem to consider for thick structures. In addition, the Navier’s analytical solution is implemented to extract the system’s natural frequency for simply-supported plates. The findings of this paper indicate on the fact that the vibration suppression in the nanocomposite structures can be delayed if a high value is assigned to the characteristic relaxation time of the polymer. Besides, it is illustrated that hybrid nanocomposites consisted of wavy CNTs (i.e., corresponding with more realistic case) cannot provide ideal frequencies related to the nanocomposites manufactured from straight CNTs.

Using a Tuned-Inerto-Viscous-Hysteretic-Damper (TIVhD) for vibration suppression in multi-storey building structures

This paper explores the use of a novel tuned-inerto-viscous-hysteretic-damper (TIVhD) for reducing the seismic response of multi-storey building structures. The TIVhD is an inerter-based damper device consisting of a linear hysteretic damper connected in series with an inerto-viscous damper. The layout of TIVhD is similar to that of tuned-inerter-hysteretic-damper (TIhD) with an additional viscous damping element in parallel with an inerter. The design is motivated by the fact that most inerter designs cannot completely remove the parasitic damping due to friction, fluid compression, etc. Moreover, the use of linear hysteretic damping is considered to be a more realistic approach when material damping is present. In this paper, the TIVhD is installed between the ground and the first-storey and is tuned by firstly assumed the viscous damping coefficient to be zero. Then the other three parameters are optimised following the tuning procedure of the TIhD that is based on the fixed-point theory with additional fine-tuning procedure by targeting the first vibration mode of the multi-storey structure. The optimum TIVhD parameters are finally obtained using two scenarios: (1) amplifying its viscous damping coefficient and stiffness while keeping the inertance constant; (2) amplifying its inertance and stiffness while keeping the viscous damping constant. Both scenarios are aiming at the same reduction level of that given by the TIhD. Finally, the effectiveness of the TIVhD on reducing the structural response is demonstrated for both harmonic and seismic base excitation cases in the time domain. This has been made possible by a newly developed time domain response of linear hysteretic damping via the Hilbert transform and a time reversal technique.

Vibration suppression of an elastic beam with boundary inerter-enhanced nonlinear energy sinks

Nonlinear vibration absorbers have been widely used for vibration suppression of elastic structures, but they were usually placed within the structures. However, designing such a vibration damping device within an engineering structure is possibly difficult. In this paper, an inertial nonlinear energy sinks (NES) is mounted on the boundaries of the elastic beam to suppress its vibration. Although this vibration suppression approach is more in line with engineering requirements, it introduces nonlinear oscillators at boundaries. This brings certain difficulties to the structural vibration analysis and the optimal absorber design. An approximate analytical approach for the steady-state response is developed in this work and verified by numerical solutions. The comparison with the uncontrolled system demonstrates the high-efficiency vibration suppression of the inertial NES installed on the boundary. Besides, the optimization of the NES parameters is performed. Resonance amplitude of the elastic structure can be reduced by 98% with the optimized NES. In summary, this paper proposes a novel approach to suppress the bending vibration of elastic structures through boundary NESs. The vibration reduction effect is very significant, and it is more feasible to implement. Therefore, this work is helpful to study the vibration of elastic structures with nonlinear boundaries and to promote the application of nonlinear vibration absorbers. A boundary damping strategy is proposed to solve the problem of the difficulty of installing the vibration absorber in engineering. Introduce an inertial nonlinear energy sinks (NES) to reduce the weight of the shock absorber. The nonlinear boundary is separated and merged into the elastic beam vibration control equation to realize the decoupling of the continuum model. Resonance peak of the elastic structure can be reduced by 98% with the optimized NES. This work is helpful to study the vibration of elastic structures with nonlinear boundaries and to promote the application of nonlinear vibration absorbers.

Vibration suppression of a rotating functionally graded beam with enhanced active constrained layer damping treatment in temperature field

This paper investigates the vibration control of a rotating functionally gradient material (FGM) beam under thermal environment by using an enhanced active constrained layer damping (EACLD) treatment. The present model is extended from a newly developed dynamic model for composite EACLD beams. The difference is that the base beam is composed of temperature-dependent FGM that was widely used in the aerospace industry as advanced heat-resisting composite and the temperature dependence of viscoelastic material in the constrained layer is also considered. The active piezoelectric layer has edge elements at both ends, which are modeled as equivalent springs and mass points. The Lagrange’s equation is used to derive the dynamic equations of the system and the deformation of the beam is described by the assumed-mode method. Based on the rigid-flexible coupling dynamic theory, the dynamic responses of the rotating FGM beam with various temperature differences are investigated. Simulation results show that the vibration suppression performance of the EACLD beam is better than the ACLD beam. The equivalent springs have more significant influences on the structural vibration suppression effect than the mass points. The larger the temperature difference is, the larger the thermal induced flutter of the structure is. The influences of VEM damping layer thickness, rotating speed, and control gain on the vibration of the structure with EACLD treatment are also discussed.

Vibration suppression of structures using tuned mass damper technology: A state-of-the-art review

To date, considerable attention has been paid to the development of structural vibration suppression techniques. Among all vibration suppression devices and techniques, the tuned mass damper is one of the most promising technologies due to its mechanical simplicity, cost-effectiveness, and reliable operation. In this article, a critical review of the structural vibration suppression using tuned mass damper technology will be presented mainly focused on the following four categories: (1) tuned mass damper technology and its modifications, (2) tuned mass damper technology in discrete and continuous structures (mathematical modeling), (3) optimization procedure to obtain the optimally designed tuned mass damper system, and (4) active tuned mass damper and semi-active tuned mass damper with the practical realization of the tuned mass damper technologies.

Nonlinear vibration suppression of composite laminated beam embedded with NiTiNOL-steel wire ropes

NiTiNOL-steel wire rope (NiTi-ST) is a new vibration absorber with nonlinear stiffness and hysteretic damping. Although there are many studies on NiTi-ST nonlinear identification, there are few studies on vibration suppression for laminated structures with NiTi-ST. In the present work, the NiTi-ST is integrated with a composite laminated beam for structural vibration suppression for the first time. A coupling model of the composite laminated beam embedded with NiTi-ST is proposed. The nonlinear restoring force and hysteretic damping force of NiTi-ST are processed into polynomial form. The responses of the beam embedded with different NiTi-ST are investigated by the Galerkin discretization together with the harmonic balance method (HBM). The terms of the polynomial model are discussed. Two numerical methods are utilized for steady-state responses and numerical validations. Simulation results demonstrate the effectiveness of NiTi-ST. This vibration suppression method can be popularized for other laminated structures and contribute to vibration control in engineering fields.

A new design of unsymmetrical shunt circuit with negative capacitance for enhanced vibration control

Piezoelectric elements are widely used in structural vibration suppression. The applicable bipolar voltage of a piezoelectric element is unsymmetrical, but in most control systems, the voltage on the piezoelectric actuator is applied symmetrically, which greatly wastes the driving capability. In synchronized switching damping (SSD) approaches for structural vibration control, the damping effect depends on the effective voltage range on the piezoelectric actuator. A novel method of realizing unsymmetrical bipolar voltage with SSD method based on negative capacitance shunt circuit for vibration control is proposed for improvement of the control performance in this study. A resistance and a diode that added into constructed negative capacitance circuit are used to realize unsymmetrical bipolar voltage. The general expression of the switched voltage on the piezoelectric actuator is derived. The stability of negative capacitance shunt circuit is addressed. The added offset resistance in the negative capacitance circuit plays an important role in system stability. The simulation analysis results agree very well with the theoretical results, both of which reveal that the unsymmetrical voltage ratio depends on the resistance in the negative capacitance circuit. Finally, experiments are carried out to verify the designed circuit and the excellent damping performance.

Vibration suppression of the horizontal flexible plate using proportional– integral–derivative controller tuned by particle swarm optimization

This paper presents the development of an active vibration control for vibration suppression of the horizontal flexible plate structure using proportional–integral–derivative controller tuned by a conventional method via Ziegler–Nichols and an intelligent method known as particle swarm optimization algorithm. Initially, the experimental rig was designed and fabricated with all edges clamped at the horizontal position of the flexible plate. Data acquisition and instrumentation systems were designed and integrated into the experimental rig to collect input–output vibration data of the flexible plate. The vibration data obtained through experimental study was used to model the system using system identification technique based on auto-regressive with exogenous input structure. The plate system was modeled using particle swarm optimization algorithm and validated using mean squared error, one-step ahead prediction, and correlation tests. The stability of the model was assessed using pole zero diagram stability. The fitness function of particle swarm optimization algorithm is defined as the mean squared error between the measured and estimated output of the horizontal flexible plate system. Next, the developed model was used in the development of an active vibration control for vibration suppression on the horizontal flexible plate system using a proportional–integral–derivative controller. The proportional–integral–derivative gains are optimally determined using two different ways, the conventional method tuned by Ziegler–Nichols tuning rules and the intelligent method tuned by particle swarm optimization algorithm. The performances of developed controllers were assessed and validated. Proportional–integral–derivative-particle swarm optimization controller achieved the highest attenuation value for first mode of vibration by achieving 47.28 dB attenuation as compared to proportional–integral–derivative-Ziegler–Nichols controller which only achieved 34.21 dB attenuation.

Thermally induced vibration suppression in a thermoelastic beam structure

In this paper, the problem of thermally induced vibration suppression in a thermoelastic beam is studied. Physical equivalent of the present problem is that a thermoelastic beam is suddenly entering into daylight zone and vibrations are induced due to heating on the upper surface of the beam or thermoelastic beam in a spacecraft enters to intensive sunlight area just after leaving a shadow of a planet. Thermally induced vibrations are suppressed by means of minimum using of control forces to be applied to dynamic space actuators. Objective functional of the problem is chosen as a modified quadratical functional of the kinetic energy of the thermoelastic beam. Necessary optimality condition to be satisfied by an optimal control force is derived in the form of maximum principle, which converts the optimal vibration suppression problem to solving a system of distributed parameters system linked by initial-boundary-terminal conditions. Solution of the system is achieved via MATLAB? and simulated results reveal that thermally induced vibration suppression by means of dynamic space actuators are very effective and robust.

Research on the configuration of cable-driven parallel robots for vibration suppression of spatial flexible structures

Specific satellites with ultra-long wings easily suffer from violent vibrations caused by the external disturbance and self-rotation, which do harm to flexible wings and affect the normal operation of satellites. In severe cases, the satellites would be damaged. Therefore, achieving rapid vibration suppression is particularly critical. Besides, to protect flexible wings from damage and reduce energy consumption, the control force should be small. Considering the above two issues comprehensively, a scheme using cable-driven parallel robots (CDPRs) to suppress vibrations is proposed. Furthermore, the influence of different configurations of CDPRs on the control effect is studied in the paper. First, the dynamic model of the CDPR which is comprised of four cables and a flexible structure is established using the finite element method. Then, the dynamic behavior of the model under the controllable cable force is analyzed by the Newmark-β method. An optimization index including the settling time, the maximum cable force and energy consumption is presented. Based on the index, six kinds of CDPRs with different configurations are tested under the control of the proposed Fuzzy-PID method and an active control method, respectively. As a comparison, a passive control scheme is also tested. Finally, numerical simulations are implemented to evaluate the effect of the vibration suppression, and the results are satisfactory.

Study on vibration characteristics of sandwich beam with BCC lattice core

In this study, the vibration characteristics of a sandwich lattice beam have been studied using an analytical approach and finite element(FE) analyses. In the analytical approach, a sixth-order partial differential equation for expressing the motion in terms of the transverse displacement has been solved, which is assumed that the sandwich core is deformed mainly by the shear load. Here, a new theoretical approach for predicting the equivalent shear modulus GC∗ of the lattice core is proposed. The analytical prediction of the natural frequency, accounting for transverse shear, agrees well with the FE results. Also, the vibration response of the first-order natural frequency f1 exhibits a upwardly convex curve as the strut diameter increases, suggesting that there is a maximum value of the frequency f1 for a given facesheet thickness tf. Moreover, it is observed that the maximum frequency of the sandwich lattice beam is always greater than that for a continuum beam, which ensures the effectiveness of the lattice core in enhancing the vibration response. Therefore, vibration suppression in aircraft structures can be achieved by introducing lattice sandwich panels.

Aeolian Vibration Control of Power Transmission Line Using Stockbridge Type Dampers — A Review

Due to its inherent low damping, a power transmission line is prone to wind induced vibration. Vibration control is needed to suppress the aeolian vibration of the transmission-line to reduce the fatigue and to extend its service life. Though patented in 1928, more than 90 years ago, the Stockbridge damper or its variants are still commonly used for vibration suppression of conductors in modern day power transmission systems because of their advantages of simple structure, low cost, reliable operation and effective vibration suppression. This paper offers a comprehensive review of the development, modeling, analysis, and design of the Stockbridge-type dampers and their applications in Aeolian vibration control of power transmission lines. A Stock bridge-type damper is a dumbbell-shaped device that consists of a short messenger cable with two masses at the ends and a clamp at the middle to attach to a conductor. The friction among the strands in the messenger cable dissipations energy. A Stock bridge-type damper is essentially a tuned mass damper. For the modeling of a Stockbridge damper alone, the classis linear mechanics analysis, the nonlinear analysis, and finite element method (FEM) are reviewed. For the modeling of the combined damper and conductor system, this paper mainly reviews the Energy Balance Principle (EBP) that is relatively easy to use and can obtain the energy dissipated by the damper. Two important design issues, the damper parameter sensitivity analysis and damper location optimization, are discussed in this paper. This paper also briefly reviews the experimentation and fatigue related to a Stockbridge damper. In addition, this paper provides an outlook of future development, analysis, and application of Stockbridge-type dampers for conductor vibration control.

Vibration response and band gap characteristics of functionally graded frame structure

Vibration response and band gap characteristics of the functionally graded frame structures are investigated based on the first-order shear deformation theory. The material properties of functionally graded material rods vary continuously in thickness direction according to a power law. Spectral stiffness matrix of the periodic functionally graded material frame structure in the global coordinate system is derived in detail. Consequently, the vibration band gap properties of the functionally graded material frame structure can be calculated and analyzed by using the spectral element method. The calculation accuracy for dynamic responses of the functionally graded material frame structure is validated by the finite element method. The results demonstrate that the wider band gaps in the low and medium frequency ranges can be achieved for the functionally graded frame structures comparing with the homogeneous ones. Moreover, the frequency windows and ranges for the band gaps of the functionally graded material frame structure can be effectively adjusted through designing the gradient indexes for the functionally graded material rods, which provide a novel idea for vibration suppression of frame structures.