Shunt Damping Research Articles

Multimodal shunt damping of monolithic bladed drums using multiple digital vibration absorbers

Abstract Based on a digital realization of piezoelectric shunt circuits, this works presents a proof-of-concept damping approach tailored to address the complex dynamics of monolithic bladed drums (BluMs) and attenuate their vibrations. This approach comprises the simultaneous use of multiple digital vibration absorbers (DVAs) together with a mean shunt strategy, taking advantage of the fact that multiple absorbers act simultaneously on the structure and that the blade modes of BluMs appear closely-spaced. In order to target multiple groups of modes, this strategy is incorporated in a multi-staged shunt circuit. The damping concept is numerically and experimentally demonstrated on a BluM with multiple piezoelectric patches, proving its ability to achieve excellent damping performance on multiple groups of modes. This performance is shown to be relatively insensitive to the spatial distribution of the shunted patches. Based on a robustness study, it was also found that the shunts are robust to changes in the host structure which could, e.g., be due to mistuning. Owing their digital nature, DVAs are easily adjustable making them highly attractive in practical applications.

Design and test of a contactless damper for HTS maglev systems via electromagnetic shunt dampers

High-temperature superconducting (HTS) maglev system is promising to become the future high-speed transport due to its numerous advantages. However, the low-damping dynamic characteristics of superconductors make the system vulnerable to external disturbances, which present a significant challenge to its implementation. To enhance the vibration attenuation effect of the HTS maglev system, a non-contact damper that employs electromagnetic shunt damping (EMSD) and negative resistance is incorporated into the HTS maglev system. This study elucidates the principles of EMSD and negative resistance, and establishes the governing equations to describe the behavior of the HTS maglev model equipped with EMSD. Subsequently, the EMSD coupling coefficients are analysed via the finite element method (FEM) under varying conditions. Finally, a dedicated vibration test rig is designed and fabricated to validate the effectiveness of the proposed damper. The results demonstrate that the proposed damper, in combination with negative resistance, is capable of effectively suppressing vibration in HTS maglev systems. The maximum acceleration of the test model can be reduced by 86% compared with the original system without the damper. This work may provide valuable guidance for future practical implementations.

Vibration control and energy harvesting of offshore wind turbines installed with TMDI under dynamical loading

This study investigates the performance of multiple tuned mass-damper-inerter with multiple electromagnetic motor (TMDI-EM) for the dual objectives of enhancing energy harvesting and dynamic performance in offshore wind turbines (OWTs). OWTs, inherently susceptible to dynamic sensitivity under lateral loads such as wind and waves, necessitate effective solutions for vibration mitigation while harnessing energy from dynamic excitations. The TMDI-EM configuration integrates an electromagnetic motor (EM) as a shunt damper between a secondary mass and an inerter element in series. The scalable inertance of the inerter element allows for adaptability in practical device implementations. Genetic Algorithm (GA) is employed to find optimum parameters for the TMDI-EM system. The research focuses on the dynamic response of OWTs under real-world conditions, where wind and wave forces act as correlated random excitations. Parametric analyses assess the available energy for harvesting at the EM and the displacement variance of the OWT structure as the inertance of the TMDI-EM varies. The study employs methods to optimize the TMDI-EM parameters using Genetic Algorithm, ensuring the system's optimal performance for both enhanced energy harvesting and dynamic response. The findings indicate that lightweight TMDI-EMs, representing only 1.5 % of the OWT structure's mass, demonstrate improved vibration suppression and energy harvesting performance with increasing inertance. This study contributes into the potential integration of TMDI-EMs to enhance the dynamic performance and energy harvesting capabilities of offshore wind turbines under dynamical loading conditions. The use of Genetic Algorithm ensures the identification of optimal parameters for the TMDI-EM system, enhancing its practical applicability.

Design of LC Filter with Shunt Damping Resistor for Non-linear Load to Reduce the Total Harmonic Distortion in Load Voltage

The electrical power distribution system is the part of a power system, which supplies electrical power to consumers for utilization. Recently the utilization of nonlinear loads has been increasing in distribution system which badly affected the sinusoidal output voltage waveform. Every consumer of electricity demand consistent and sinusoidal voltage waveform to run their loads properly but due to power quality issues such as harmonics, voltage sag, voltage swell, flickering, and interruption of power supply which badly affect the output voltage of the loads may result in equipment damages, and financial loss. This research study discusses the voltage harmonic which is one of the power quality problems. The harmonic is a Non sinusoidal waveform that is generated due to the applications of nonlinear loads which affect the power system reliability, increase the transformer losses, line losses, and frequent faults are generated which results in poor utility revenue, and reduction in production in industries. So, in this research study, the LC filter with a damping resistor is designed to improve the output voltage waveform. The MATLAB simulation model is developed to analyze the performance of the distribution system under linear and nonlinear loads with and without an LC filter circuit and also THD% is analyzed through FFT.

Vibration control by using active electromagnetic shunt damper

It is well-known that the traditional electromagnetic shunt damping (EMSD) techniques are limited by the damping force of electronic components and require a negative resistance (NR) shunt circuit to enhance performance. However, the NR shunt circuit could lead to the EMSD system being unstable. Addressing this, this study proposes an advanced control system that employs active control technology combined with EMSD for vibration control. We first developed a dimensionless mathematical model of the control system, which was then finely tuned using an adaptive simulated annealing particle swarm optimization algorithm. Subsequently, the relationship between control gain and optimal shunt circuit parameters was predicted using a BP neural network. Finally, the proposed Active-EMSD (AEMSD) was experimentally verified. The experimental results demonstrate that the proposed AEMSD not only surpasses traditional thresholds but also excels in isolating low-frequency vibrations. Compared to traditional EMSD, the proposed AEMSD showed improved effectiveness.

Vibration Modal Analysis of Superconducting Levitation With LCR Shunt Damper

Vibration Modal Analysis of Superconducting Levitation With LCR Shunt Damper

Calibration of multiple shunted piezoelectric transducers with correction for residual modes and shunt interactions

Piezoelectric shunt damping can be used for efficient vibration mitigation of a single or multiple vibration modes of a structure. Several analytical tuning expressions have been derived for numerous circuit topologies for a single shunt. However, when multiple shunted piezoelectric transducers are attached to a flexible structure, their individual interactions alongside the spill-over from residual modes affect the calibration accuracy. In this paper, explicit correction terms that represent these effects are presented for multiple shunted piezoelectric transducers targeting a single vibration mode. The correction terms are obtained from the evaluation of effective electromechanical coupling factors, while proper balancing between shunts follows from an assumed proportionality between shunt forces. The proposed correction method is applicable to general shunt architectures, for which tuning is available when targeting a single-degree-of-freedom structure. Its ability to regain nearby optimal damping properties is illustrated numerically for the classic series RL shunt.

Tunable shunting periodic acoustic black holes for low-frequency and broadband vibration suppression

Acoustic Black Holes (ABH) embedded within structures can efficiently damp vibrations above the cut-on frequency but fails below it, particularly when the flexural wavelength exceeds the size of the ABH. Therefore, addressing low-frequency vibration mitigation becomes imperative. Periodic ABH structures and shunt damping have been employed individually and proved effective, yet their combined application has not been explored previously. This paper introduces a novel approach for broadband vibration mitigation. It combines a periodic ABH beam, damping layer, and a resonant element comprising a piezoelectric patch and an inductance–resistance shunting circuit (referred as lossy PZT-ABH metabeam). This design addresses the shortcomings in the attenuation performance within the pass bands of conventional periodic structures and allows for easy adjustment of the attenuated bands without the need for physical structural modification. To characterize this system, a semi-analytical model of the electromechanical problem is developed using the Rayleigh–Ritz method, and the complex dispersion curve is obtained to evaluate the mitigation performance. The obtained results are validated against Finite Element Method (FEM) simulations, demonstrating that the lossy PZT-ABH metabeam achieves broadband vibration mitigation covering the entire frequency spectrum with remarkable flexibility. To facilitate designs, a detailed analysis is conducted on the length and attached position of the piezoelectric patch, thickness of the damping layer and the value of inductance and resistance. Furthermore, a thorough investigation into the mechanism of electromechanical resonance (ER) is carried out to deepen our understanding of the ER attenuated band.

Ultra-Low Frequency Vibration Isolation of Cockroach-Inspired Structures With Electromagnetic Shunt Damping Enhanced by Geometric Nonlinearity

Ultra-Low Frequency Vibration Isolation of Cockroach-Inspired Structures With Electromagnetic Shunt Damping Enhanced by Geometric Nonlinearity

Passive vibration control of subsonic thin plate via nonlinear capacitance and negative capacitance coupled piezoelectric shunt damping

As part of the aircraft wing, the thin plate is always affected by external airflow and harmonic excitation to generate undesirable nonlinear vibration behaviors, which will produce fatigue and damage to the aircraft. Therefore, it is necessary to develop some schemes for vibration control of subsonic thin plates. This work proposes a nonlinear piezoelectric shunt damping for nonlinear vibration control of subsonic thin plates. The nonlinear motion equation of the electromechanical coupling system is established by the extended Hamilton principle. The subsonic aerodynamic model is introduced by linear potential flow theory. Three different piezoelectric control circuits made up of inductance, resistance, nonlinear capacitance, and negative capacitance are considered. The nonlinear dynamic equations are solved by the Matcont toolbox. The first four generalized coordinates before and after the piezoelectric vibration control of the system are discussed. It can be observed that piezoelectric control has significant vibration suppression effects. The vibration control effects of three different piezoelectric control circuits are compared under different external excitation amplitude and airflow velocities. This study provides a relatively perfect piezoelectric control scheme for the vibration control of thin plates in subsonic airflow.

Vibration Suppression of Superconducting Magnetic Levitation System by LCR Parallel Electromagnetic Shunt Damper

Vibration Suppression of Superconducting Magnetic Levitation System by LCR Parallel Electromagnetic Shunt Damper

Novel hybrid-controlled graded metamaterial beam for bandgap tuning and wave attenuation

In this paper, a tunable functionally graded metamaterial beam is designed for flexural wave attenuation by integrating piezomagnetic shunt damping system and inertial amplification mechanism. The proposed piezomagnetic shunt damping system is a complex mechanic–magnetic–electrical coupling system, which aims to transform and consume the vibration energy through local resonance to form a bandgap with tunable and strong wave attenuation ability. Based on Timoshenko beam theory, the wave equation and transmission spectrum of the metamaterial beam are derived by using transfer matrix method. The theoretical results are compared with the numerical simulation results. The results show that the resonance characteristics of piezomagnetic shunt circuit lead to negative group velocity and strong wave attenuation(−30 dB) at frequency defined by inductance and capacitance in shunt circuit. In varying frequency regimes, the coupled bandgap width can be maximized to 1925 Hz by tuning the external capacitance and coil turns. The superposition of double attenuation peaks caused by inertial amplification mechanism and local resonance coupling can be generated in the bandgap, allowing wave attenuation up to −94 dB. Subsequently, the attenuation capability of locally resonant bandgap can be significantly enhanced without changing the frequency by introducing the negative resistance into shunt circuit. Furthermore, the initiation and termination frequencies of bandgap can be flexibly designed by important material and structural parameters. This work is expected to provide valuable research ideas for the application of advanced intelligent materials in the field of vibration and noise reduction.

Multi-objective parameter optimization of electromagnetic shunt damper for high-Temperature superconducting maglev vehicle system

High-temperature superconducting pinning maglev technology has great potential for high-speed transportation due to its passive stability and friction-free characteristics. However, at high speeds, the weak damping characteristics of the system make it challenging to attenuate system vibrations caused by external excitation effectively. An electromagnetic shunt damper can be added to the high-temperature superconducting vehicle system to address this challenge. However, due to the complexity of the high-temperature superconducting vehicle system and external excitation, it is challenging to determine the optimal electromagnetic shunt damper parameters through analytical calculation. This study proposes a method for optimizing electromagnetic shunt damper parameters based on the NSGA-II multi-objective optimization algorithm. The high-temperature superconducting vehicle dynamic simulation model with electromagnetic shunt damper is established, and the dynamic simulation is carried out according to the actual operation conditions. Taking the dynamic indexes as the objectives, the optimal electromagnetic shunt damper parameters are then selected within a reasonable range based on dynamic indexes used as objectives in the NSGA-II algorithm. The effectiveness of the optimization method is verified through simulations and experiments on a levitation model vehicle with electromagnetic shunt damper under random vibration conditions. Finally, the optimized electromagnetic shunt damper parameters are applied to an engineering high-speed high-temperature superconducting pinning maglev vehicle through simulation. The calculation results demonstrate that various performance indexes are improved after optimization. This optimization design provides a reference for applying electromagnetic shunt damper in high-temperature superconducting pinning maglev vehicles.

Hybrid analytical H-norm optimization approach for dynamic vibration absorbers

Conventionally, single-targeted H∞ or H2 optimization methods are adopted to determine the optimal parameters of different Dynamic Vibration Absorbers (DVAs) individually. A generic analytical framework for various DVAs considering a dual-target of H∞ and H2 norms is lacking. Addressing these issues, a hybrid analytical H∞-H2 optimization approach is proposed, leading to closed-form optimal solutions characterized by equal-height fixed points and conditional minimum H2-norms, combining the advantages of H∞ and H2 solutions. The proposed method is completely based on arbitrary filter coefficients of the targeted transfer function. Therefore, it can be generically applied for various DVAs. With the proposed method, the analytical optimal parameters of Negative-Stiffness Inerter-based Tuned Mass Systems (NS-ITMSs) are obtained based on an extended generic representation model considering multiple parameters. In extension, the method is illustratively applied on three complicated DVAs, including a Lever-type Inerter-based Vibration Absorber with Negative Stiffness (NS-LIVA) considering a leverage effect, a Piezoelectric Shunt Damping System (PSDS) considering an electro-mechanical coupling effect, and a Negative-Stiffness Tuned Viscous Mass Damper (NS-TVMD) for vibration isolator considering a transmissibility target. The closed-form solutions for these advanced DVAs are obtained for engineering reference. Furthermore, this method can be extended for more complicated energy dissipation or harvesting techniques.

Study on the vibration suppression of beam structures with nonlinear piezoelectric shunt damping

The vibration suppression of the nonlinear beam structure under harmonic excitations by employing the nonlinear piezoelectric shunt damping circuit (PSDC) is researched. The energy approach is utilized to deduce the dynamic equations of the nonlinear beams with nonlinear PSDC. The complexification-averaging approach and pseudo arc-length continuation approach are applied to calculate the frequency domain response of the beam structure. Numerous numerical examples are conducted to verify the present formulations, thereby demonstrating the remarkable efficiency and accuracy. The impacts of several parameters of the proposed PSDC are discussed and the optimal study of the nonlinear PSDC is further performed to obtain the optimal negative and nonlinear capacitances. The comparisons concerning the vibration of the beam structures with and without PSDC are implemented to examine the vibration mitigation performance of the designed PSDC. In the end, the design criterion of the nonlinear PSDC is given.

Semi-analytical dynamic modeling and vibration reduction analysis of the blisk structure with piezoelectric shunt damping patches

To suppress the harmful vibration of blisks, a method of uniformly distributing piezoelectric shunt damping patches (PSDPs) on blades is described. Taking the simplified blisk as the object, the semi-analytical model of blisk with PSDPs is established and the vibration reduction effect of the piezoelectric shunt damping is analyzed based on the created dynamic model and the experimental system. In the process of modeling, the piezoelectric effect is reasonably simulated, and the electromechanical coupling expressions of the blisk structure with uniformly distributed piezoelectric patches are derived according to the Lagrange energy equations. Further, the resistance (R) and resistance-inductance (RL) series shunt are equivalent to frequency-dependent viscoelastic damping and are introduced into the semi-analytical model of the blisk in the form of complex stiffness. A case study is carried out on the blisk with four equally attached PSDPs. Based on the experimental results, the rationality of the dynamic model is proved. At the same time, theoretical analysis and experiments show that piezoelectric shunt damping has a certain damping effect on the blisk. Finally, based on the established model, the influence of different piezoelectric shunt parameters (resistance values, inductance values), the attachment positions of piezoelectric patches, and different piezoelectric patch types on the vibration reduction effect of the blisk are emphatically analyzed. The results show that there is an optimal resistance value for the R shunt circuit, and an optimal resistance and inductance value for the RL series shunt circuit to make the vibration reduction effect optimal; the piezoelectric patch attached on the root of the blade and selecting piezoelectric patch with large electromechanical coupling coefficient are beneficial to vibration reduction.

Dual-Functional Energy Harvesting and Low-Frequency Vibration Attenuation: Electromagnetic Resonant Shunt Series Quasi-Zero-Stiffness Isolators

In recent times, there has been a significant focus on electromagnetic resonant shunt damping (ERSD) and quasi-zero-stiffness vibration isolators (QZS VI) as prominent solutions for vibration mitigation or energy harvesting. In this paper, an innovative retrofittable model is proposed for dual-functional energy harvesting and low-frequency vibration attenuation by combining the ERSD and two-stage quasi-zero-stiffness vibration isolator (TQZS VI). The viscous dissipative element between the TQZS VI upper and lower layers is implemented using an electromagnetic shunt transducer that is connected in parallel with a resonant RLC (resistor–inductor–capacitor) circuit. Firstly, the mathematical model of the electromagnetic resonant shunt series quasi-zero-stiffness isolator (ERS-TQZS VI) is developed. Then, the magnitude-frequency response equations of the ERS-TQZS VI system are approximately solved using the harmonic balance method (HBM) in combination with the pseudo-arc-length method (PLM). The analytical approach is validated using numerical simulations. Moreover, the force transmissibility and output power of the ERS-TQZS VI are defined, and detailed parametric analysis for energy harvesting and low-frequency vibration attenuation is performed to assess the critical design parameters that result in optimal performance of the ERS-TQZS VI. The results demonstrate that the ERS-TQZS VI exhibits a significant reduction in resonance peaks of low-frequency vibration while simultaneously enabling effective vibration energy harvesting.

Vibration Suppression on the Composite Laminated Plates Subjected to Aerodynamic and Harmonic Excitations Based on the Nonlinear Piezoelectric Shunt Damping

This paper proposes a nonlinear piezoelectric shunt damping circuit to mitigate the vibration of the plate structures subjected to the aerodynamic and harmonic excitations. The nonlinear piezoelectric shunt damping circuit consisting of the piezoelectric patch, inductor, resistor, negative capacitor and nonlinear capacitor is considered. Firstly, the governing equations of the electro-mechanical coupling nonlinear system are formulated based on the energy method and modified Ritz method. Furthermore, the complexification-averaging method combined with pseudo arc-length continuation method is adopted to analyze the steady-state response of the coupled system with aerodynamic and harmonic forces. A considerable number of numerical cases are performed to validate the proposed model and the time domain and frequency domain dynamic responses of the plate structures with and without control are further compared to validate the effectiveness of the proposed control strategy. Meanwhile, the energy transfer analysis between the plate structure and external piezoelectric shunt damping circuit is investigated. Finally, the effects of key parameters of the nonlinear piezoelectric shunt damping circuit including the negative capacitance and nonlinear capacitance on the vibration suppression performance of the piezoelectric shunt damping are discussed.

Sensitive analysis on added damping of shunted piezoceramic damping: cantilever and simply supported beam

The current research investigates the prediction of piezoelectric damping of resistively shunted beams caused by resistors via joule heating. In order to maximize the extra damping of the piezoelectric shunted beam system, a sensitivity analysis was done. The geometrical impacts on the maximum additional damping simulation are investigated for different length and thickness ratios with the position of the PZT-5H from the base of the cantilever and simply supported beams. Prior to doing sensitivity analysis, a mathematical model for estimating extra damping from voltage produced. Validation experiments are also carried out.

Direct Adaptive SSDV Circuit for Piezoelectric Shunt Damping

Piezoelectric shunt damping is widely studied to suppress vibration of thin structures via shunting an attached piezoelectric transducer with an electrical impedance. The SSDV (synchronized switch damping on voltage) technique can be used to enhance the damping effect. However, SSDV is not stable in the weak excitation. Although some adaptive SSDV circuits have been developed to tackle the stability problems, additional monitoring devices are required to feed back the vibration strength signal for adjusting the series voltage sources. We here present a new direct adaptive SSDV (DA-SSDV) method without additional excitation level monitoring module, based on the ratio of the maximum piezovoltage and the value of the series voltage sources. A compact DA-SSDV circuit is designed with low-cost off-the-shelf discrete components. The close-loop control of the series voltage sources is realized simply through a passive envelope detector and a resistive voltage divider. Experimental results show the DA-SSDV circuit avoids the stability problems and possesses a good displacement transmissibility around 6.2, a fast voltage adjustment response speed above 5 V/s and a high operation sensitivity with the open-circuit piezovoltage of 540 mV. The DA-SSDV shows great application value in the compact and low-power vibration control systems.