Showing papers on "Dynamic Vibration Absorber published in 2023"
TL;DR: In this paper , the inertance effect in an inerter eddy current damper (IECD) was used to construct a dynamic vibration absorber for the seismic protection of civil structures.
4 citations
TL;DR: In this paper , the influence law of vibration absorbers on the rail corrugation was investigated and the optimization methods of absorbers were studied from the perspectives of the connection stiffness, connection damping and different installation methods.
Abstract: Rail corrugation in the sharp curved section with Cologne-egg fasteners is suppressed by vibration absorbers, in which the suppression mechanism is unclear and the optimization method of the vibration absorber needs to be further investigated. Firstly, the complex eigenvalue and dynamic transient methods are adopted to investigate the vibration inducement of rail corrugation and influence law of vibration absorber on the rail corrugation. Then, the optimization methods of absorbers are studied from the perspectives of the connection stiffness, connection damping and different installation methods of absorbers. Results show that vibration inducement of rail corrugation in the sharp curved section with Cologne-egg fasteners includes the friction-induced oscillation of the entire system and feedback oscillation of undulatory wear. The installation of the vibration absorber can effectively weaken the impact of the vibration inducement, thereby inhibiting the rail corrugation. When the vertical and lateral connection stiffness are 120 MN·m−1 and 60 MN·m−1 respectively, the vertical and lateral connection damping are 100 kN·s·m−1 and 50 kN·s·m−1 respectively, the vibration absorber has the best effect of suppressing rail corrugation. Moreover, the continuous installation on both rail webs can be adopted to achieve the better inhibitory effect of the absorber.
4 citations
TL;DR: In this article , the effects of magnetic constraints on a piezoelectric energy harvesting absorber while simultaneously controlling a primary structure and harnessing energy were investigated and developed using the Euler-Lagrange principle.
Abstract: This study investigates the effects of magnetic constraints on a piezoelectric energy harvesting absorber while simultaneously controlling a primary structure and harnessing energy. An accurate forcing representation of the magnetic force is investigated and developed. A reduced-order model is derived using the Euler–Lagrange principle, and the impact of the magnetic force is evaluated on the absorber’s static position and coupled natural frequency of the energy harvesting absorber and the coupled primary absorber system. The results show that attractive magnet configurations cannot improve the system substantially before pull-in occurs. A rigorous eigenvalue problem analysis is performed on the absorber’s substrate thickness and tip mass to effectively design an energy harvesting absorber for multiple initial gap sizes for the repulsive configurations. Then, the effects of the forcing amplitude on the primary structure absorber are studied and characterized by determining an effective design of the system for a simultaneous reduction in the primary structure’s motion and improvement in the harvester’s efficiency.
3 citations
TL;DR: In this article , a self-learning tuning method for the vibration absorbers is proposed based on a large number of experimental vibration data, which contains the actual information of the optimal absorber parameters.
2 citations
TL;DR: In this article , a low-frequency micro-vibration absorber based on a beam with designable nonlinear stiffness is presented, and the effects of structural parameters on the stiffness characteristics of the designed beam are discussed to explore the lowfrequency performance.
2 citations
TL;DR: In this article , a viscoelastic Maxwell-type DVA model with an inerter and multiple stiffness springs is investigated with the combination of the traditional theory and an intelligent algorithm.
Abstract: Dynamic vibration absorbers (DVAs) are widely used in engineering practice because of their good vibration control performance. Structural design or parameter optimization could improve its control efficiency. In this paper, the viscoelastic Maxwell-type DVA model with an inerter and multiple stiffness springs is investigated with the combination of the traditional theory and an intelligent algorithm. Firstly, the expressions and approximate optimal values of the system parameters are obtained using the fixed-point theory to deal with the H∞ optimization problem, which can provide help with the range of parameters in the algorithm. Secondly, we innovatively introduce the particle swarm optimization (PSO) algorithm to prove that the algorithm could adjust the value of the approximate solution to minimize the maximum amplitude by analyzing and optimizing the single variable and four variables. Furthermore, the validity of the parameters is further verified by simulation between the numerical solution and the analytical solution using the fourth-order Runge–Kutta method. Finally, the DVA demonstrated in this paper is compared with typical DVAs under random excitation. The timing sequence and variances, as well as the decreased ratios of the displacements, show that the presented DVA has a more satisfactory control performance. The inerter and negative stiffness spring can indeed bring beneficial effects to the vibration absorber. Remarkably, the intelligent algorithm can make the resonance peaks equal in the parameter optimization of the vibration absorber, which is quite difficult to achieve with theoretical methods at present. The results may provide a theoretical and computational basis for the optimization design of DVA.
2 citations
TL;DR: In this paper , a three-element DVA model was proposed to improve vibration reduction of an undamped primary system under excitation by combining the control effect of the inerter device and grounded positive stiffness.
Abstract: Improving the control performance of dynamic vibration absorbers has recently been effective by introducing a grounded negative stiffness device. However, the negative stiffness structure is unstable and difficult to achieve in engineering practice , and its major drawback is that it amplif ies the vibration response of the primary system at low frequency region. Meanwhile, some mechanical devices can be combined to make the DVA work even better with a grounded positive stiffness. For this purpose, this paper combines for the first time the control effect of the inerter device and grounded positive stiffness into a three-element DVA model in order to better improve vibration reduction of an undamped primary system under excitation. First, the dynamic equation of motion of the system is written according to Newton ’s second law. Then, the steady-state displacement response of the primary system under harmonic excitation is calculated. In order to minimize the resonant response of the primary system around its natural frequency, the extended fixed point theory is applied. Thus, the optimized parameters such as the tuning frequency ratio, the stiffness ratio , and the approximate damping ratio are determined as a function of mass ratio and inerter – mass ratio. From the results analysis, it was found that the inerter – mass ratio has a better working range to guarantee the stability of the coupled system. Then , study on the effect of inerter – mass ratio on the primary system response is carried out. It can be seen that increasing the inerter – mass ratio in the optimal working range can reduce the response of the primary system beyond its uncontrolled static response. However, it is necessary to avoid the situation where the inerter – mass ratio is very large because it can lead to unrealistic optimal parameters. Finally, comparison with other DVA models is show n under harmonic and random excitation of the primary system. It is found that the proposed DVA model in this paper has high control performance and can be used in many engineering practice s .
1 citations
TL;DR: In this article , a data-driven method is developed based on EDRB to design the distributed DVAs for the broadband vibration suppression of thin-walled structures, which has strong robustness to noise and broadens the vibration suppression effective of each DVA by use of ESM.
Abstract: It is generally impractical to design Dynamic Vibration Absorbers (DVAs) according to each vibration mode for the vibration suppression of complex flexible structures due to the dense vibration modes. DVAs design according to the Excitation-Dependent Representative Basis (EDRB) derived in Li et al. (2021) allows one DVA to suppress the vibration response dominated by multiple closely-space modes, which broadens the application of the DVAs in vibration control. A data-driven method is developed based on EDRB to design the distributed DVAs for the broadband vibration suppression of thin-walled structures. Via the singular value decomposition on structural response data, both structural vibration modes and the EDRB can be obtained for well separated modes and closely-space modes, respectively. These derived structural vibration modes and EDRB will be regarded as the targeted “modes” and suppressed by the further designed distributed DVAs with one DVA per targeted “mode”. The vibration suppression of a simply-supported plate subjected to a concentrated dynamic force is firstly investigated to verify the effectiveness of the proposed method. Then, the distributed DVAs design for the vibration suppression of a complex fairing structure subjected to distributed dynamic force is conducted to show the applicability of the proposed method on complex engineering structures. Results show that the proposed data-driven method has a similar vibration suppression effect to the method in Li et al. (2021), and a better performance than the traditional method proposed by Zhu et al. (2018). • A data-driven design method of distributed vibration absorber suitable for broadband vibration suppression is proposed. • Only strain response data is needed for the proposed distributed dynamic vibration absorber design method. • The method has strong robustness to noise and broaden the vibration suppression effective of each DVA by use of ESM.
1 citations
TL;DR: In this article , the authors proposed a novel dynamic vibration absorber (DVA) with lever, inerter, and grounded stiffness, based on H∞ optimization criterion, two possible optimal parameter designs of the proposed model are obtained.
Abstract: In this paper, we propose a novel Maxwell dynamic vibration absorber (DVA) with lever, inerter, and grounded stiffness. Firstly, the governing equation of the coupled system is established. The analytical formula of the amplitude amplification factor of the primary system and the natural frequencies of the coupled system are derived. There are three fixed points in the amplitude–frequency response curve of the primary system, which are independent of damping. Then, based on H∞ optimization criterion, two possible optimal parameter designs of the proposed model are obtained. Considering the practical engineering application and ensuring the stability of the system, the optimal grounded stiffness ratio is selected, and six working ranges of inerter–mass ratio are calculated. Furthermore, the performance of the vibration reduction is compared for six cases. It is found that when the values of the mass ratio, lever amplification ratio, and inerter–mass ratio change in different intervals, and the optimal grounded stiffness ratio has different cases of negative, zero, and positive results. Especially when the stiffness coefficient of the viscoelastic Maxwell model and another grounded stiffness are positive at the same time, the vibration absorption effect is better theoretically. Finally, comparing with the traditional DVAs, the performance of the novel DVA is better under harmonic excitation and random excitation. The results could provide theoretical guidance for the design of inerter-based Maxwell-type DVA with a lever component.
1 citations
TL;DR: In this paper , a combined vibration isolation (CVI) system consisting of a quasi-zero stiffness (QZS) system and a linear dynamic vibration absorber (DVA) is investigated.
01 Jan 2023
TL;DR: In this article , the authors developed a method for obtaining analytical suboptimal designs, specifically approximate optimal designs, for a dynamic absorber for parametric excitation through two kinds of free vibration systems constructed by approximating the original system.
TL;DR: In this paper , the authors examined the issue of the chassis system of a high-speed electric train with body inclination and a vibration recovery system, and the advantages of using an electromechanical shock absorber over hydraulic, pneumatic and similar systems.
Abstract: The article examines the issue of the chassis system of a high-speed electric train with body inclination and a vibration recovery system. The advantages of using an electromechanical shock absorber over hydraulic, pneumatic and similar systems are described. The authors considered the main characteristics of the DC electromechanical shock absorber. The main overall parameters of the shock absorber were presented. Attention is paid to the relevance of using an electromechanical shock absorber of a linear type, in comparison with analogues, including the ability to recover energy. Attention is drawn to the structure of the DC electromechanical shock absorber. The functional control scheme of the electromechanical shock absorber is considered and the control algorithm is described. The calculation areas of the parameters of the electromechanical shock absorber are determined. A 3D model of an electromechanical shock absorber in the Ansys Electronics software environment is presented. A finite-element mesh was built for further calculations of the magnetic field and inductance. In the article, attention is paid to the calculation of the magnetic field in the most intense mode. A picture of the shock absorber's magnetic field at the maximum working clearance was obtained and interim results were discussed. The results of calculating the inductance depending on the operating gap of the shock absorber are presented. Conclusions were made based on the results of calculations of magnetic and electrical parameters of an electromechanical shock absorber based on a linear direct current motor.
TL;DR: In this paper , the authors proposed a novel damping device, NiTiNOL-steel wire rope, which is a vibration absorber with linear hysteresis damping, nonlinear damping and nonlinear stiffness.
Abstract: This paper proposes a novel damping device, NiTiNOL–steel wire rope, which is a vibration absorber with linear hysteresis damping, nonlinear damping, and nonlinear stiffness. This study is the first to couple the NiTi–ST damping device with the functionally graded material beam model. The Runge–Kutta method and harmonic balance method are adopted to study the resonant response of the system from the numerical and analytical aspects, respectively. It proves that NiTi–ST provides effective vibration reduction for FGM beam structures. In addition, special attention is paid to the appearance of the closed detached response, which significantly affects the resonant peak value of the system. And the CDR phenomenon is eliminated by adjusting the parameters, and a good damping effect is achieved under large external excitation. Results confirm that NiTi–ST is a promising nonlinear damper that serves as a new method for the vibration suppression of continuum structures.
TL;DR: In this paper , the nonlinear motion states of the structure under different excitation conditions were analyzed to explore the inherent relation between the chaotic and large amplitude motion and the vibration absorber's operating performance.
Abstract: A conventional dynamic vibration absorber based on resonance effect can hardly satisfy the requirement for low-frequency and broadband vibration control in actual engineering. Combined with passive and nonlinear vibration absorption strategy, this study employed nonlinear characteristics of the magnetic force, bistable structure to establish the dynamic model of the main system with a bistable vibration absorber. The nonlinear motion states of the structure under different excitation conditions were analyzed to explore the inherent relation between the chaotic and large amplitude motion and the vibration absorber’s operating performance. The effect laws of the structural parameters on the dynamic characteristics of the nonlinear vibration absorber and the main system were developed to obtain the optimal parameter settings in the case of resonance and off-resonance of the main system. These results provide an insightful theoretical foundation for the optimal design of the nonlinear vibration absorber.
TL;DR: In this article , a lever-type Inerter-based Vibration Absorber (LIVA) is proposed, which is based on a lever supported on a flexible auxiliary structure connecting between the primary structure and a paralleled inerterdashpot system.
TL;DR: In this paper , the authors investigated the control performance of grounded dynamic vibration absorber (DVA) with pendulum connected via the lever mechanism and found that the amplified mass ratio has greatly vibration reduction effect, which push the peak resonant vibration of the primary system smaller than its static response without control.
Abstract: This paper investigates the control performance of grounded dynamic vibration absorber (DVA) with pendulum connected via the lever mechanism. These optimal parameters are found based on the extended fixed point theory. However, in the optimal equivalent stiffness derivation process, it was found that the amplified mass ratio could only take limited values to guarantee the stability condition of the coupled system and make positive equivalent stiffness. As a result, the best working range of the amplified mass ratio was established. The results analysis of the influence of system parameters on the primary system response shown that the amplified mass ratio has greatly vibration reduction effect, which push the peak resonant vibration of the primary system smaller than its static response without control. To better understand the control performance of the proposed DVA, three other dynamic vibration absorbers with or without negative stiffness are considered. The control performance comparison show that under harmonic excitation or even random excitation of the primary system, the proposed DVA model has a significant vibration reduction effect compared to the considered its DVA counterparts. The interest of these relevant results can be used in the field of vibration control engineering.
TL;DR: In this paper , the authors presented an innovative hybrid shock absorber with variable damping and stiffness using the magnetorheological fluid and MR elastomer, respectively, and compared the performance of the proposed isolator over the passive system and reveal that the vehicle stability was improved by 87.5% to 92% and ride comfort is improved by 84.85% to 85.99%.
TL;DR: In this paper, the authors proposed a new class of metamaterial beams of tunable and multi-band vibration absorption, composed of uniform and periodic beam cells with locally resonant substructure called dual-action vibration absorber, DA.
Abstract: This paper presents a new class of metamaterial beams of tunable and multi-band vibration absorption. The metamaterial beam is composed of uniform and periodic beam cells with locally resonant substructure called dual-action vibration absorber, DA. A DA vibration absorber comprising of three locally resonant subsystems, 3-DOF spring-mass-damper subsystems, is utilized to generate frequency stopbands to stop elastic wave propagation. The governing equations of motion for a periodic beam cell are derived. Several distinct mass and stiffness configurations for the metamaterial beam with DA vibration absorber are proposed. The dispersion relations and presence of three frequency stopbands are studied. A finite element method based on Timoshenko beam theory is used to model and analyze the introduced metamaterial beam with DA vibration absorber. The frequency response simulations agree well with the projected stopbands of the developed dispersion relations of the mass and stiffness configurations. The concept of the presented metamaterial beam with tunable and multi-stopbands is promising for wave propagation attenuation and control applications.
TL;DR: In this article , a nonlinear dynamic absorber was used as a cantilever beam with a concentrated mass at its end to reduce the amplitude of the intensified oscillator vibration.
Abstract: One of the important methods to prevent the intensification of the main vibration system is using a dynamic vibration absorber (DVA). A DVA is a mechanical subsystem used to reduce Vibration amplitude and prevent the main vibration system from resonance. This paper aims to use a nonlinear dynamic absorber as a cantilever beam with a concentrated mass at its end to reduce the amplitude of the intensified oscillator vibration. The primary vibration system consists of mass, nonlinear spring, and viscous damping, and a harmonic excitation force is applied to it, resonance the system. In this case, using a nonlinear dynamic absorber reduces the vibration amplitude. For this purpose, first, the kinetic energy and the potential energy of the vibration system are calculated, and then, using Lagrange equations, the governing equations are extracted. Due to the nonlinearity of the equations of motion, the multiple scales method is used to solve the governing equations. In the results, the effect of nonlinear DVA on reducing the amplitude of intensified oscillator vibration is well visible. The effect of the main parameters of nonlinear dynamic absorbers on the vibration amplitude of the initial system is also investigated. Finally, the vibration amplitude of the system is optimized as a target function by the genetic algorithm method, and the optimal parameters of the nonlinear dynamic absorber and the optimal vibration amplitude are studied. Considering the main resonant vibration system as a structure under earthquake, the results of this research in reducing the vibration amplitude can be widely used in earthquake engineering.
TL;DR: In this paper , the optimal design of the damped dynamic vibration absorber (DVA) for damped primary systems was studied. But the design of DVA was not discussed.
Abstract: Abstract: Eccentricity vibration: - Eccentricity is defined as the offset between the axis of rotation and the axis of symmetric. Dynamic vibration absorber: It is a tuned spring mass system, which reduces or eliminates the vibration of a harmonically excited system. The concept behind these passive components is simply to add a spring and mass that have a natural frequency tuned to that of the resonant excitation frequency of the system. Doing so transfers all of the resonance energy of the system to the Dynamic Vibration Absorber, leaving the original system undisturbed. This study focuses on the optimum design of the damped dynamic vibration absorber (DVA) for damped primary systems. This design in the future to further characterize or improve the system performance
TL;DR: In this article , a wave absorption control method for reducing vibrations in multi-degree-of-freedom systems semi-actively using a magnetorheological elastomer-based dynamic absorber is proposed.
Abstract: Severe vibration may occur in structures such as high-rise buildings and bridges according to wind and seismic excitations, and in large space structures due to their lightweight and flexible constitution. Generally, when several vibration modes are simultaneously excited, application of the model-based control strategies become difficult. In this study, we propose a wave absorption control method for reducing vibrations in multi-degree-of-freedom systems semi-actively using a magnetorheological elastomer-based dynamic absorber. The stiffness of the absorber is changeable according to the applied magnetic field strength. The value is tuned adaptively so that the mechanical impedance at the boundary meets an absorptive boundary requirement. Analytical investigation clarified relationship between the excitation frequency and absorber stiffness that could eliminate the wave reflection from the boundary and maintain no resonant state in the system. Based on this stiffness condition, numerical simulation and experiment for the wave absorption control were performed. The proposed absorber to be used with the wave control scheme was found to significantly reduce structural vibrations within the stiffness variable range.
TL;DR: In this paper , a model-free virtual vibration absorber control law was proposed to reduce the forced vibration amplitude caused by spindle unbalance by up to 85% in a high-precision vertical grinding machine.
TL;DR: In this article , a nonlinear active dynamic vibration absorber based on passivity-based energy shaping control is proposed to control the vibrations that are excited by force and velocity disturbances simultaneously.
Abstract: In this article, a nonlinear active dynamic vibration absorber based on passivity‐based energy shaping control is proposed. Using the proposed method, the vibrations that are excited by force and velocity disturbances simultaneously can be controlled. The control law only uses the relative displacement and velocity of the vibration system, which can be easily measured by sensors. The numerical solutions to the partial differential equations are not required in our proposed method. The main idea of the controller's parameters design is to convert a plant system with a nonlinear dynamic vibration absorber into a desired system with multiple virtual skyhook dampers. We also derive the parameters' selection guidelines for the proposed controller. The global asymptotical stability is guaranteed through passivity‐based control theory, although the parameter design is based on linearization. We verify the effectiveness of the proposed controller by some simulations on a cart‐pendulum system.