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1
Kłosiński, Jacek, Ludwik Majewski e Arkadiusz Trąbka. "Control of Two-Dimensional Vibrating System". Solid State Phenomena 164 (giugno 2010): 333–38. http://dx.doi.org/10.4028/www.scientific.net/ssp.164.333.
Testo completoAbstract (sommario):
A strategy for control of a system of two electrical vibrators mounted onto the vibrating plate of a typical small table vibrator was discussed in the present paper. The aim of the considered control system is rapid positioning of counterbalances for ensuring achievement of the assumed directions of vibrations and loading forces (where , m is unbalanced mass, ω is angular velocity of the vibrator shaft, e is distance between the unbalanced mass and the vibrator rotary axis). The strategy of the control consists in setting of different directions of vibrator rotations together with controlled change of vibration frequency and amplitude. Numerical analysis was performed. The obtained results are presented in a graphical form.
2
Oliinyk, O. Yu. "VIBRATION FREQUENCY DENSITY CONTROL METHOD IN VIBRATION CONDITIONS". METHODS AND DEVICES OF QUALITY CONTROL, n. 2(43) (24 dicembre 2019): 41–47. http://dx.doi.org/10.31471/1993-9981-2019-2(43)-41-47.
Testo completoAbstract (sommario):
The use of existing vibration frequency measuring instruments for monitoring technological parameters inside apparatus and equipment is limited due to the presence of vibrations and industrial noise. The lack of data on the use of part of the technological apparatus as flow resonators through the unexplored basic analytical equations for determining the amplitude-frequency characteristics of such resonators determined the direction of these studies. The article is devoted to studies aimed at establishing the relationship between the vibrational field of the resonator, which is used as part of the technological apparatus with a controlled environment, and its reaction in the form of a change in the frequency or amplitude of the resonator’s own vibrations, which carries information about the properties of the substance in the apparatus. The experimental setup diagram, experimental methodology, and data on determining the oscillation frequency of the resonator under vibration conditions for metallic (corrosion-resistant steel) and non-metallic (organic glass) resonators are presented. The curves obtained from the experimental values were approximated using linear and hyperbolic approximations. It was found that the use of hyperbolic approximation reduces the average approximation error by more than six times. It was found that the error of the hyperbolic approximation error does not exceed 0.022% for a metal resonator and 0.05% for an organic glass resonator. The conducted experimental studies confirm the presence of a determinate coupling of the measured frequency characteristics of the resonator with the density, which was measured inside the equipment. The obtained data was used to develop the scientific and methodological foundations of the vibrational frequency control method in conditions of vibration using a part of the device as a resonator of the vibrational frequency sensor.
3
Fardelin, Gustav, Niklas Ricklund e Ing-Liss Bryngelsson. "Hand nerve function after mountain bike cycling". Journal of Science and Cycling 11, n. 3 (31 dicembre 2022): 23–32. http://dx.doi.org/10.28985/1322.jsc.10.
Testo completoAbstract (sommario):
Hand-arm vibrations can cause permanent injuries and temporary changes affecting the sensory and circulatory systems in the hands. Vibrational effects have been thoroughly studied within the occupational context concerning work with handheld vibrating tools. Less is known about vibrational exposure and risk of effects during cycling. In the present study, 10 cyclists were recruited for exposure measurements of hand-arm vibrations during mountain bike cycling on the trail, and the effects on the nerve function were examined with quantitative sensory testing (QST) before and after the ride.
The intervention group was compared to a control group that consisted of men exposed to hand-arm vibrations from a polishing machine. The results of the QST did not statistically significantly differ between the intervention and study groups. The intervention group showed a lesser decrease in vibration perception in digitorum II, digitorum V, and hand grip strength than the control group. It was concluded that no acute effects on nerve function in the dominant hand were measured after mountain bike cycling on the trail, despite high vibration doses through the handlebars.
4
Vasilyev, Andrey. "ANALYSIS OF THE FACTORS DECREASING THE EFFICIENCY OF OPERATION OF ACTIVE NOISE AND VIBRATION CONTROL SYSTEMS IN DUCTS AND THE WAYS OF IMPROVEMENT OF PROTECTION". Akustika, VOLUME 41 (2021): 205–9. http://dx.doi.org/10.36336/akustika202141205.
Testo completoAbstract (sommario):
The factors influencing on the active noise and vibration control system efficiency of operation and the ways of the system protection improvement are discussed. Analysis of factors decreasing the efficiency of operation of active noise and vibration control systems in ducts is showing that there are such factors as physical characteristics of operating medium (temperature, pressure, moisture, vibrations, dust), masking acoustic and vibrating interferences of other sources of noise and vibration etc., which may significantly reduce the efficiency, reliability and durability of active systems operation. The ways of improvement of protection of the elements of the active noise and vibration control system are discussed. Further improvement of active noise control and vibration system elements protection allows the system to operate with higher efficiency and reliability. Widely, achieving of good results in the solution of this problem helps us to extend the possibilities of active noise and vibration control systems practical application.
5
Ryabov, Victor M., e Boris A. Yartsev. "Composite wing vibration coupling control". Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy 10, n. 2 (2023): 344–56. http://dx.doi.org/10.21638/spbu01.2023.214.
Testo completoAbstract (sommario):
The paper discusses the possibility to control coupled bending-twisting vibrations of composite wing by means of the monoclinic structures in the reinforcement of the plating. Decomposing the potential straining energy and kinetic energy of natural vibration modes into interacting and non-interacting parts, it became possible to introduce the two coefficients that integrally consider the effect of geometry and reinforcement structure upon the dynamic response parameters of the wing. The first of these coefficients describes the elastic coupling of the natural vibration modes, the second coefficient describes the inertial one. The paper describes the numerical studies showing how the orientation of considerably anisotropic CRP layers in the plating affects natural frequencies, loss factors, coefficients of elastic and inertial coupling for several lower tones of natural bending-twisting vibrations of the wing. Besides, for each vibration mode, partial values of the above mentioned dynamic response parameters were determined by means of the relationships for orthotropic structures where instead of “free” shearing modulus in the reinforcement plant, “pure” shearing modulus is used. Joint analysis of the obtained results has shown that each pair of bendingtwisting vibration modes has its orientation angle ranges of the reinforcing layers where the inertial coupling caused by asymmetry of the cross-section profile with respect to the main axes of inertia decreases, down to the complete extinction, due to the generation of the elastic coupling in the plating material. These ranges are characterized by the two main features: 1) the difference in the natural frequencies of the investigated pair of bendingtwisting vibration modes is the minimum and 2) natural frequencies of bending-twisting vibrations belong to a stretch restricted by corresponding partial natural frequencies of the investigated pair of vibration modes. This result is of practical importance because it enables approximate analysis of real composite wings with complex geometry in the existing commercial software packages.
6
Mistry, Yash Ashwin, e Kushagra Goel. "Surface Mounted Active Vibration Cancellation Device Using Raspberry Pi". ECS Transactions 107, n. 1 (24 aprile 2022): 19289–97. http://dx.doi.org/10.1149/10701.19289ecst.
Testo completoAbstract (sommario):
Active vibration cancellation device detects vibrations on a host surface using a piezoelectric vibration sensor, amplifies them using a signal amplifier, and sends them to a Raspberry Pi board implemented with PID control, responsible for signal processing, which further actuates Piezoelectric actuators vibrating at a phase difference of 180° to the vibrating surface (destructive interference) and reduces the vibrations over the surface. The device presented in this paper suggests an application that tries to make it accessible to a large group of people.
7
Fang, Mingxing, Lijun Wu, Jing Cheng, Youwu Du e Jinhua She. "Active Structural Control Based on Integration ofΗ∞Control and Equivalent-Input-Disturbance Approach". Journal of Advanced Computational Intelligence and Intelligent Informatics 20, n. 2 (18 marzo 2016): 197–204. http://dx.doi.org/10.20965/jaciii.2016.p0197.
Testo completoAbstract (sommario):
This paper describes an approach for suppressing earthquake-induced vibrations of building structures. The design of the control system is based on the equivalent-input-disturbance approach for improving the vibration rejection performance. A control system configuration with a vibration estimator is described, and a method of designing such a control system that employsΗ∞control is presented. The vibration rejection performance is guaranteed by the control structure, in which an equivalent vibration signal on the control input channel is estimated and directly incorporated into the control input. The validity of our method is demonstrated through simulations.
8
Zhang, Ting, e Hongguang Li. "Adaptive modal vibration control for smart flexible beam with two piezoelectric actuators by multivariable self-tuning control". Journal of Vibration and Control 26, n. 7-8 (6 gennaio 2020): 490–504. http://dx.doi.org/10.1177/1077546319889842.
Testo completoAbstract (sommario):
It has been popular for decades that the vibrations of space structures are suppressed with smart actuators. However, the higher mode vibrations are often motivated when a control strategy is applied to attenuate the vibration for the smart structures. Moreover, if the multi-mode vibration of a smart structure is suppressed with multi-actuators, a proper multivariable control law will be adopted to solve the coupling problem caused by the multi-actuators of the smart structure. Therefore, in the paper, a decoupling technique for two modal vibrations of a smart flexible beam with two piezoelectric patches is adopted by adaptive control. The proposed control law is designed with a multivariable minimum variance self-tuning control. Considering the first two orders of modal vibrations, two piezoelectric patches are configured on the flexible beam according to the strain of the first two orders of modal vibrations along the longitudinal direction of the beam. A dynamical model for the flexible beam with two piezoelectric actuators is constructed by the mode superposition method. With the dynamical model, simulations are implemented to suppress the free vibration of the flexible beam. Moreover, experiments are carried out to verify the effectiveness of the multivariable minimum variance self-tuning control for vibration suppression of the flexible structure. The control results clearly show that the free vibration amplitude of the cantilevered beam with two control voltages applied to the two piezoelectric patches is less than that with one control voltage applied to the first piezoelectric actuator. Thus, multivariable minimum variance self-tuning control is a more efficient approach for suppressing multimodal vibration for a smart flexible beam with two piezoelectric actuators compared with the conventional velocity feedback control.
9
Lian, Jijian, Yan Zheng, Chao Liang e Bin Ma. "Analysis for the Vibration Mechanism of the Spillway Guide Wall Considering the Associated-Forced Coupled Vibration". Applied Sciences 9, n. 12 (25 giugno 2019): 2572. http://dx.doi.org/10.3390/app9122572.
Testo completoAbstract (sommario):
During the flood discharge in large-scale hydraulic engineering projects, intense flow-induced vibrations may occur in hydraulic gates, gate piers, spillway guide walls, etc. Furthermore, the vibration mechanism is complicated. For the spillway guide wall, existing studies on the vibration mechanism usually focus on the vibrations caused by flow excitations, without considering the influence of dam vibration. According to prototype tests, the vibrations of the spillway guide wall and the dam show synchronization. Thus, this paper presents a new vibration mechanism of associated-forced coupled vibration (AFCV) for the spillway guide wall to investigate the dynamic responses and reveal coupled vibrational properties and vibrational correlations. Different from conventional flow-induced vibration theory, this paper considers the spillway guide wall as a lightweight accessory structure connected to a large-scale primary structure. A corresponding simplified theoretical model for the AFCV system is established, with theoretical derivations given. Then, several vibrational signals measured in different structures in prototype tests are handled by the cross-wavelet transform (XWS) to reveal the vibrational correlation between the spillway guide wall and the dam. Afterwards, mutual analyses of numeral simulation, theoretical derivation, and prototype data are employed to clarify the vibration mechanism of a spillway guide wall. The proposed mechanism can give more reasonable and accurate results regarding the dynamic response and amplitude coefficient of the guide wall. Moreover, by changing the parameters in the theoretical model through practical measures, the proposed vibration mechanism can provide benefits to vibration control and structural design.
10
Shimose, Shigeru, Kanjuro Makihara e Junjiro Onoda. "Comparison of Analog and Digital Self-Powered Systems in Multimodal Vibration Suppression". Smart Materials Research 2012 (21 febbraio 2012): 1–9. http://dx.doi.org/10.1155/2012/287128.
Testo completoAbstract (sommario):
This paper compares our analog and digital self-powered systems for vibration suppression, and shows experimental results of multimodal vibration suppression for both self-powered systems. The experimental results are evaluated in light of the damping performance and adaptability under various vibrational conditions. We demonstrate various examples of our innovative vibration suppression method, called “digital self-powered.” Proper status switching of an electric circuit made up of an inductor and a selective switch connected to a piezoelectric transducer attenuates the vibrations. The control logic calculation and the switching events are performed with a digital microprocessor that is driven by the electrical energy converted from the mechanical vibration energy. Therefore, this vibration suppression system runs without any external power supply. The self-powering feature makes this suppression method useful in various applications. To realize an ideal vibration suppression system that is both self-powered and effective in suppressing multimode vibration, sophisticated control logic is implemented in the digital microprocessor. We demonstrate that our digital self-powered system can reduce the vibrational displacements of a randomly excited multimodal structure, by as much as 35.5%.
11
Beltran-Carbajal, Francisco, Hugo Yañez-Badillo, Ruben Tapia-Olvera, Antonio Favela-Contreras, Antonio Valderrabano-Gonzalez e Irvin Lopez-Garcia. "On Active Vibration Absorption in Motion Control of a Quadrotor UAV". Mathematics 10, n. 2 (13 gennaio 2022): 235. http://dx.doi.org/10.3390/math10020235.
Testo completoAbstract (sommario):
Conventional dynamic vibration absorbers are physical control devices designed to be coupled to flexible mechanical structures to be protected against undesirable forced vibrations. In this article, an approach to extend the capabilities of forced vibration suppression of the dynamic vibration absorbers into desired motion trajectory tracking control algorithms for a four-rotor unmanned aerial vehicle (UAV) is introduced. Nevertheless, additional physical control devices for mechanical vibration absorption are unnecessary in the proposed motion profile reference tracking control design perspective. A new dynamic control design approach for efficient tracking of desired motion profiles as well as for simultaneous active harmonic vibration absorption for a quadrotor helicopter is then proposed. In contrast to other control design methods, the presented motion tracking control scheme is based on the synthesis of multiple virtual (nonphysical) dynamic vibration absorbers. The mathematical structure of these physical mechanical devices, known as dynamic vibration absorbers, is properly exploited and extended for control synthesis for underactuated multiple-input multiple-output four-rotor nonlinear aerial dynamic systems. In this fashion, additional capabilities of active suppression of vibrating forces and torques can be achieved in specified motion directions on four-rotor helicopters. Moreover, since the dynamic vibration absorbers are designed to be virtual, these can be directly tuned for diverse operating conditions. In the present study, it is thus demonstrated that the mathematical structure of physical mechanical vibration absorbers can be extended for the design of active vibration control schemes for desired motion trajectory tracking tasks on four-rotor aerial vehicles subjected to adverse harmonic disturbances. The effectiveness of the presented novel design perspective of virtual dynamic vibration absorption schemes is proved by analytical and numerical results. Several operating case studies to stress the advantages to extend the undesirable vibration attenuation capabilities of the dynamic vibration absorbers into trajectory tracking control algorithms for nonlinear four-rotor helicopter systems are presented.
12
Mori, Kentaro. "Vibrator, vibration unit, and vibrator control method". Journal of the Acoustical Society of America 120, n. 6 (2006): 3445. http://dx.doi.org/10.1121/1.2409421.
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Yasuda, Masashi. "Vibration control unit and vibration control body". Journal of the Acoustical Society of America 123, n. 3 (2008): 1229. http://dx.doi.org/10.1121/1.2901336.
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Ding, Hu, e J. C. Ji. "Vibration control of fluid-conveying pipes: a state-of-the-art review". Applied Mathematics and Mechanics 44, n. 9 (settembre 2023): 1423–56. http://dx.doi.org/10.1007/s10483-023-3023-9.
Testo completoAbstract (sommario):
AbstractFluid-conveying pipes are widely used to transfer bulk fluids from one point to another in many engineering applications. They are subject to various excitations from the conveying fluids, the supporting structures, and the working environment, and thus are prone to vibrations such as flow-induced vibrations and acoustic-induced vibrations. Vibrations can generate variable dynamic stress and large deformation on fluid-conveying pipes, leading to vibration-induced fatigue and damage on the pipes, or even leading to failure of the entire piping system and catastrophic accidents. Therefore, the vibration control of fluid-conveying pipes is essential to ensure the integrity and safety of pipeline systems, and has attracted considerable attention from both researchers and engineers. The present paper aims to provide an extensive review of the state-of-the-art research on the vibration control of fluid-conveying pipes. The vibration analysis of fluid-conveying pipes is briefly discussed to show some key issues involved in the vibration analysis. Then, the research progress on the vibration control of fluid-conveying pipes is reviewed from four aspects in terms of passive control, active vibration control, semi-active vibration control, and structural optimization design for vibration reduction. Furthermore, the main results of existing research on the vibration control of fluid-conveying pipes are summarized, and future promising research directions are recommended to address the current research gaps. This paper contributes to the understanding of vibration control of fluid-conveying pipes, and will help the research work on the vibration control of fluid-conveying pipes attract more attention.
15
Nagai, Nobuyuki, Seiji Hashimoto, Yoshimitsu Fujikura, Jyunpei Takahashi, Shunji Kumagai, Makoto Kasai, Kenji Suto e Hiroaki Okada. "Reproduction of Vehicle Vibration by Acceleration-Based Multi-Axis Control". Applied Mechanics and Materials 251 (dicembre 2012): 129–33. http://dx.doi.org/10.4028/www.scientific.net/amm.251.129.
Testo completoAbstract (sommario):
This paper presents the development of the 3-axis vibrating machine precisely reproducing vehicle's acceleration characterized with multi-mode vibration. For the reproduction in vertical axis, at first, the system identification experiment of the vibrator is carried out. Using the identified model, the feedforward control based on the pole-zero cancellation method is applied to realize the ideal transfer gain of one from the acceleration reference to its output. Next, for reproducing the acceleration in horizontal plane, the continuous-path tracking (CPT) control system is constructed using the precision XY stage. In the CPT control system, the disturbance observer is introduced focusing on the accurate reproduction within limited frequency. Finally, the experimental verification of the proposed 3-axis acceleration vibration reproduction system is shown using the developed DSP-controlled 3-axis vibrating machine.
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Sun, J. Q., M. A. Norris, D. J. Rossetti e J. H. Highfill. "Distributed Piezoelectric Actuators for Shell Interior Noise Control". Journal of Vibration and Acoustics 118, n. 4 (1 ottobre 1996): 676–81. http://dx.doi.org/10.1115/1.2888351.
Testo completoAbstract (sommario):
Structural controls have been recently used to reduce acoustic radiation from vibrating structures. It is well known that in some cases, a control system can reduce the noise and, at the same time, increase the structural vibration. This is one of the concerns with the structural control approach to solve the noise problem. Developing a control system that can reduce the noise and structural vibration at the same time is an important task. This paper proposes one of possible approaches for accomplishing this task. The emphasis of the present approach is not on control strategies, but rather on the design of distributed piezoelectric actuators for the structural control system. In the paper, we study the interior noise radiation and the structural vibrations of uniform cylindrical shells, which are taken as a simplified model of a fuselage section. Two distributed piezoelectric actuators are developed based upon the understanding of the structural-acoustic coupling properties of the system. These actuators can reduce the shell structural vibration and the interior noise at the same time in a wide range of frequencies by using only the acoustic error sensors. Hence, an optimal noise reduction is achieved. Computer simulations and the experiments have shown that the actuators can lead to global noise and vibration reduction. Excellent agreement between the analytical predictions and the experiments strongly supports the theoretical development.
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Rajabpour, Leila, Hazlina Selamat, Alireza Barzegar e Mohamad Fadzli Haniff. "Design of a robust active fuzzy parallel distributed compensation anti-vibration controller for a hand-glove system". PeerJ Computer Science 7 (29 ottobre 2021): e756. http://dx.doi.org/10.7717/peerj-cs.756.
Testo completoAbstract (sommario):
Undesirable vibrations resulting from the use of vibrating hand-held tools decrease the tool performance and user productivity. In addition, prolonged exposure to the vibration can cause ergonomic injuries known as the hand-arm vibration syndrome (HVAS). Therefore, it is very important to design a vibration suppression mechanism that can isolate or suppress the vibration transmission to the users’ hands to protect them from HAVS. While viscoelastic materials in anti-vibration gloves are used as the passive control approach, an active vibration control has shown to be more effective but requires the use of sensors, actuators and controllers. In this paper, the design of a controller for an anti-vibration glove is presented. The aim is to keep the level of vibrations transferred from the tool to the hands within a healthy zone. The paper also describes the formulation of the hand-glove system’s mathematical model and the design of a fuzzy parallel distributed compensation (PDC) controller that can cater for different hand masses. The performances of the proposed controller are evaluated through simulations and the results are benchmarked with two other active vibration control techniques-proportional integral derivative (PID) controller and active force controller (AFC). The simulation results show a superior performance of the proposed controller over the benchmark controllers. The designed PDC controller is able to suppress the vibration transferred to the user’s hand 93% and 85% better than the PID controller and the AFC, respectively.
18
Li, Shan, Liang Xu e Yu Zhang. "The Noise Control and Research of Vibration Slot in Vibrating Conveyor". Advanced Materials Research 479-481 (febbraio 2012): 1371–74. http://dx.doi.org/10.4028/www.scientific.net/amr.479-481.1371.
Testo completoAbstract (sommario):
Vibration slot, which is connected by the framework welded by the angle and the u-shaped slot formed by the stainless steel plate bending with fasteners, is an important part of the vibrating conveyor. The major function of vibration slot is carrying and conveying material. Due to vibration slot owning the thin plate structure and the flat large feature of surface, it is the primary noise source of vibrating conveyor. Therefore, it is very important to research and control the surface radiation noise of the vibration slot for reducing the noise of vibrating conveyor. This paper, through combining the finite element and the boundary element, researches noise radiation of vibration slot and understands the main noise source of vibration slot and radiation condition. The natural frequency of vibration slot, the vibratory response of vibration slot and the noise radiation of vibration slot are researched by inputting different structure parameters. Through analysis and comparison, some regularity conclusions that will provide a basis for the noise reduction of vibration slot are summarized .
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FERGUSON, N. S. "Keynote 3 Nonlinear systems for vibration control(The 12th International Conference on Motion and Vibration Control)". Proceedings of the Symposium on the Motion and Vibration Control 2014.12 (2014): _Keynote3——_Keynote3—. http://dx.doi.org/10.1299/jsmemovic.2014.12._keynote3-.
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Zhang, Dayu, e Cong Guan. "Active Vibration Control of Robot Gear System Based on Adaptive Control Algorithm". Journal of Sensors 2022 (4 luglio 2022): 1–8. http://dx.doi.org/10.1155/2022/4481296.
Testo completoAbstract (sommario):
With the aim of solving the errors of gear transmission system in the actual manufacturing process, processing and installation, and solving the the vibration and noise of the gear system caused by the deformation brought about by external excitation such as motor load and actuator, which seriously threaten the safety and stability of unit equipment, a novel active vibration suppression structure of multistage gear system with built-in piezoelectric actuator is designed to generate active control force, and it can be used on the shaft. An active controller is designed and established using FxLMS adaptive algorithm. The results of this method show that by measuring the vibration signal system, the base frequency of the high-speed gear pair is 310 Hz, and the basic frequency of the low-speed gear pair is 192 Hz. I had the adaptation snare go for almost 0.5 seconds, with a difference of 0.52%. Adaptive Trap II reached in 1 second, with a difference of 0.96%. In the active vibration suppression test, the basic frequency of the high-speed gear pair is 804 Hz, and the basic frequency of the low-speed gear connector is 500 Hz. Using the FxLMS adaptive algorithm, it is able to effectively suppress the frequency vibrations of the high-speed dual-gear and low-speed dual-gear coupling systems of multispeed gears. After being controlled by FxLMS algorithm at the second frequency of the high-speed gear, the vibration reduction is about 10 dB at the third frequency of the low-speed gear. The vibration reduction is also approximately 7 dB. This has proved that a new experiment of industrial safety can be used to accelerate the movement of gear vibrations using the FxLMS adaptation algorithm.
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Malliotakis, Georgios, Panagiotis Alevras e Charalampos Baniotopoulos. "Recent Advances in Vibration Control Methods for Wind Turbine Towers". Energies 14, n. 22 (11 novembre 2021): 7536. http://dx.doi.org/10.3390/en14227536.
Testo completoAbstract (sommario):
Wind power is a substantial resource to assist global efforts on the decarbonization of energy. The drive to increase capacity has led to ever-increasing blade tip heights and lightweight, slender towers. These structures are subject to a variety of environmental loads that give rise to vibrations with potentially catastrophic consequences, making the mitigation of the tower’s structural vibrations an important factor for low maintenance requirements and reduced damage risk. Recent advances in the most important vibration control methods for wind turbine towers are presented in this paper, exploring the impact of the installation environment harshness on the performance of state-of-the-art devices. An overview of the typical structural characteristics of a modern wind turbine tower is followed by a discussion of typical damages and their link to known collapse cases. Furthermore, the vibration properties of towers in harsh multi-hazard environments are presented and the typical design options are discussed. A comprehensive review of the most promising passive, active, and semi-active vibration control methods is conducted, focusing on recent advances around novel concepts and analyses of their performance under multiple environmental loads, including wind, waves, currents, and seismic excitations. The review highlights the benefits of installing structural systems in reducing the vibrational load of towers and therefore increasing their structural reliability and resilience to extreme events. It is also found that the stochastic nature of the typical tower loads remains a key issue for the design and the performance of the state-of-the-art vibration control methods.
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Ford, DG, A. Myers, F. Haase, S. Lockwood e A. Longstaff. "Active vibration control for a CNC milling machine". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 228, n. 2 (4 aprile 2013): 230–45. http://dx.doi.org/10.1177/0954406213484224.
Testo completoAbstract (sommario):
There is a requirement for improved three-dimensional surface characterisation and reduced tool wear when modern computer numerical control (CNC) machine tools are operating at high cutting velocities, spindle speeds and feed rates. For large depths of cut and large material removal rates, there is a tendency for machines to chatter caused by self-excited vibration in the machine tools leading to precision errors, poor surface finish quality, tool wear and possible machine damage. This study illustrates a method for improving machine tool performance by understanding and adaptively controlling the machine structural vibration. The first step taken is to measure and interpret machine tool vibration and produce a structural model. As a consequence, appropriate sensors need to be selected and/or designed and then integrated to measure all self-excited vibrations. The vibrations of the machine under investigation need to be clearly understood by analysis of sensor signals and surface finish measurement. The active vibration control system has been implemented on a CNC machine tool and validated under controlled conditions by compensating for machine tool vibrations on time-varying multi-point cutting operations for a vertical milling machine. The design of the adaptive control system using modelling, filtering, active vibration platform and sensor feedback techniques has been demonstrated to be successful.
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Jiao, Z., P. Chen, Q. Hua e S. Wang. "Adaptive vibration active control of fluid pressure pulsations". Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 217, n. 4 (1 giugno 2003): 311–18. http://dx.doi.org/10.1177/095965180321700407.
Testo completoAbstract (sommario):
Conventionally, passive hydraulic absorbers are utilized in order to reduce the vibrations of the fluid power supply systems. It is very difficult to adapt the variable operation conditions, such as inconsistent vibration frequency and varying loads. This paper presents a new vibration active control method to diminish the vibrations of the fluid power supply efficiently. This method is adaptive and robust in controlling the fluctuating frequencies and load disturbances and is capable of keeping the vibrations at a minimum level under variable pump speeds. This paper illustrates the theory and experimentation of vibration active control of a fluid power supply pipeline system in detail. The multilayer piezoelectric technology (PZT) driven orifice valve is designed with characteristics of a proportional opening area to the control voltage, a high-frequency bandwidth and small size. The adaptive-optimum control method is adopted to adjust the control parameters at any instant against emerging disturbances. Based on the test rig, different vibration control methods were applied; the results indicate and confirm the validity of this principle.
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Choi, Young, e Norman M. Wereley. "Vibration Isolation Performance of an Adaptive Magnetorheological Elastomer-Based Dynamic Vibration Absorber". Actuators 11, n. 6 (12 giugno 2022): 157. http://dx.doi.org/10.3390/act11060157.
Testo completoAbstract (sommario):
This study evaluates the vibration isolation performance of an adaptive magnetorheological elastomer (MRE)-based dynamic vibration absorber (MRE-DVA) for mitigating the high frequency vibrations (100–250 Hz) of target devices. A simple and effective MRE-DVA design was presented and its vibration isolation performance was experimentally measured. A cylindrical shaped MRE pad was configured to be operated in shear mode and also worked as a semi-actively tunable spring for achieving adaptive DVA. A complex stiffness analysis for the damper force cycle was conducted and it was experimentally observed that the controllable dynamic stiffness range of the MRE-DVA was greater than two over the tested frequency range. The transmissibility of a target system was measured and used as a performance index to evaluate its vibration isolation performance. It was also experimentally demonstrated that a better vibration isolation performance of the target device exposed to the high frequency vibrations could be achieved by using the adaptive MRE-DVA.
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Sheth, Anant J., Pratikkumar Rajendralal Parmar, Brijesh L. Solanki, Nirav Sailor, Bhavin P. Gohil e Harshitkumar A. Patel. "Vibration Control of Slab Breaker Machine by Passive Dual Mass Tuned Vibration Absorber". Applied Mechanics and Materials 592-594 (luglio 2014): 2112–16. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.2112.
Testo completoAbstract (sommario):
Tuned Vibration Absorber (TVA) is the best solution available to control/suppress vibrations of any dynamic systems. Dual mass Tuned Vibration Absorber are designed and implemented for the vibration control. Though the slab barker machine is operating at various natural frequencies, the Dual mass TVA can be designed to mitigate the vibrations depending on the position of mass. The experiments were carried out for various locations of mass. And it is found that the vibration /shock waves of slab breaker machine are absorbed by using a passive TVA system. By keeping the operating condition same it is practically found that at the location of 4cm the optimal vibration reduction obtained and the amplitude is found to be reduced by 37 %.
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Khomenko, Andrei P., Sergey K. Kargapoltsev e Andrey V. Eliseev. "Development of Approaches to Creation of Active Vibration Control System in Problems of the Dynamics for Granular Media". MATEC Web of Conferences 148 (2018): 11004. http://dx.doi.org/10.1051/matecconf/201814811004.
Testo completoAbstract (sommario):
The article deals with the development of mathematical models and evaluation criteria of the vibration field in the dynamic interactions of the elements of the vibrational technological machines for the processes of vibrational strengthening of long-length parts with help of a steel balls working medium. The study forms a theoretical understanding of the modes of motions of material particles in interaction with a vibrating surface of the working body of the vibration machine. The generalized approach to the assessment of the dynamic quality of the work of vibrating machines in multiple modes of tossing, when the period of free flight of particles is a multiple of the period of the surface oscillations of the working body, is developed in the article. For the correction of vibration field of the working body, the characteristics of dynamic interactions of granular elements of the medium are taken into account using original sensors. The sensors that can detect different particularities of interaction of the granular medium elements at different points of the working body are proposed to evaluate the deviation from a homogeneous and one-dimensional mode of vibration field. Specially developed sensors are able to register interactions between a single granule, a system of granules in filamentous structures, and multipoint interactions of the elements in a close-spaced cylindrical structure. The system of regularization of the structure of vibration fields based on the introduction of motion translation devices is proposed using the multi-point sensor locations on the working body. The article refers to analytical approaches of the theory of vibration displacements. For the experimental data assessment, the methods of statistical analysis are applied. It is shown that the peculiar features of the motion of granular medium registered by the sensors can be used to build active control systems of field vibration.
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Ikeda, Keigo, Kota Kamimori, Ikkei Kobayashi, Jumpei Kuroda, Daigo Uchino, Kazuki Ogawa, Ayato Endo et al. "Basic Study on Mechanical Vibration Suppression System Using 2-Degree-of-Freedom Vibration Analysis". Vibration 6, n. 2 (1 maggio 2023): 407–20. http://dx.doi.org/10.3390/vibration6020025.
Testo completoAbstract (sommario):
Mechanical vibrations adversely affect mechanical components, and in the worst case, lead to serious accidents by breaking themselves. To suppress vibrations, various studies have been conducted on vibration isolation, suppression, and resistance. In addition, technologies to actively suppress vibration have been rapidly developed in recent years, and it has been reported that vibrations can be suppressed with higher performance. However, these studies have been conducted mostly for low-order systems, and few studies have employed control models that consider the complex vibration characteristics of multi-degree-of-freedom (DOF) systems. This study is a basic study that establishes a control model for complex control systems, and the vibration characteristics of a 2-DOF system are calculated using the vibration analysis of a multi-DOF system. Furthermore, the vibration suppression performance of the 2-DOF system is investigated by performing vibration experiments.
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Chichkov, B. A. "TECHNIQUE OF PROCESSING OF VIBRATION MONITORING DATA, RECEIVED BY THE USE OF MICROELECTROMECHANICAL SYSTEMS". Civil Aviation High TECHNOLOGIES 22, n. 2 (24 aprile 2019): 38–48. http://dx.doi.org/10.26467/2079-0619-2019-22-2-38-48.
Testo completoAbstract (sommario):
During the operation of such machines as aviation engines and land based gas turbines, the obligatory vibration monitoring is carried out which is focused on the prevention of their possible damages and destructions during the work on resonant modes or because of material fatigue. Nowadays, as a rule, the standard or additional equipment is used for such control which includes as a component various types of one-axial vibration gauges. In most cases, the control is carried out continuously, and the frequency of registration can differ from several values for a flight to several values in a second. The data received during routine vibration monitoring is peak values of vibrations. They are diagnosed, using the pre-start control and some ways of fit and the tendency of changes of vibration during the operation. Microelectromechanical systems gaining now the increasing distribution (MEMS), as a rule, allow to obtain the data about vibro-acceleration without giving data about the frequency vibration characteristics. But also the regular equipment of vibrational control used during the operation of considered machines does not give data about the frequency vibration characteristics. However, microelectromechanical devices allow to obtain the data with the essential higher frequency of sample rate (in tens and hundreds times) in comparison with mass equipment used now for control, and to carry out the simultaneous control of vibration on three axes using one gauge. Apart from the vibration peak value the position relative to a reference point is fixed. Does the information received according to mentioned above features have better diagnostic potential? Will the array dimension received during data verification be an obstacle to the operational processing? Materials of the present article are an attempt to give answers to these questions and to make representation about possibility and features of an estimation of a technical state of machines by the results of processing of time series vibro-accelerations received with the use of such processing microelectromechanical systems. It is represented that the way of data processing of vibrating monitoring considered in the article at sufficient simplicity of realization allows to solve the problem of an estimation of a technical state of monitoring item.
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da Cunha, Bruno Sousa Carneiro, e Fábio Roberto Chavarette. "Vibration Control Applied in a Semi-Active Suspension Using Magneto Rheological Damper and Optimal Linear Control Design". Applied Mechanics and Materials 464 (novembre 2013): 229–34. http://dx.doi.org/10.4028/www.scientific.net/amm.464.229.
Testo completoAbstract (sommario):
In this paper we study the behavior of a semi-active suspension witch external vibrations. The mathematical model is proposed coupled to a magneto rheological (MR) damper. The goal of this work is stabilize of the external vibration that affect the comfort and durability an vehicle, to control these vibrations we propose the combination of two control strategies, the optimal linear control and the magneto rheological (MR) damper. The optimal linear control is a linear feedback control problem for nonlinear systems, under the optimal control theory viewpoint We also developed the optimal linear control design with the scope in to reducing the external vibrating of the nonlinear systems in a stable point. Here, we discuss the conditions that allow us to the linear optimal control for this kind of non-linear system.
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KIDA, Naohiro, Shinya HONDA e Yoshihiro NARITA. "3B11 Adaptive vibration control using self-organizing map(The 12th International Conference on Motion and Vibration Control)". Proceedings of the Symposium on the Motion and Vibration Control 2014.12 (2014): _3B11–1_—_3B11–8_. http://dx.doi.org/10.1299/jsmemovic.2014.12._3b11-1_.
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Landolsi, Fakhreddine, Slim Choura e Ali H. Nayfeh. "Control of 2D Flexible Structures by Confinement of Vibrations and Regulation of Their Energy Flow". Shock and Vibration 16, n. 2 (2009): 213–28. http://dx.doi.org/10.1155/2009/727236.
Testo completoAbstract (sommario):
In this paper, we investigate the control of 2D flexible structures by vibration confinement and the regulation of their energy flow along prespecified spatial paths. A discretized-model-based feedback strategy, aiming at confining and suppressing simultaneously the vibration, is proposed. It is assumed that the structure consists of parts that are sensitive to vibrations. The control design introduces a new pseudo-modal matrix derived from the computed eigenvectors of the discretized model. Simulations are presented to show the efficacy of the proposed control law. A parametric study is carried out to examine the effects of the different control parameters on the simultaneous confinement and suppression of vibrations. In addition, we conducted a set of simulations to investigate the flow control of vibrational energy during the confinement-suppression process. We found that the energy flow can be regulated via a set of control parameters for different confinement configurations.
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Chen, Li-Qun. "Analysis and Control of Transverse Vibrations of Axially Moving Strings". Applied Mechanics Reviews 58, n. 2 (1 marzo 2005): 91–116. http://dx.doi.org/10.1115/1.1849169.
Testo completoAbstract (sommario):
In this paper, research on transverse vibrations of axially moving strings and their control is thoroughly reviewed. In the last few decades, there have been extensive studies on analysis and control of transverse vibrations of axially moving strings because of the wide applications of many engineering devices that axially moving strings represent. In the investigations adopting linear models of moving strings, the paper summarizes recent studies on modal analysis, complicatedly constrained strings, coupled vibrations, and parametric vibration, as well as some early results. In the investigations adopting nonlinear models of moving strings, the paper presents the governing equations with large amplitude, and reviews progress on discretized or direct approximate analytical analyses and numerical approaches based on the Galerkin method or the finite difference method. Furthermore, investigations are reported on modeling of damping mechanisms as viscoelastic materials, coupled vibration of power transmission systems, and bifurcation and chaos. The state of the art of active control of moving strings is surveyed on controllability and observability, the Laplace transform domain analysis and the energy analysis, nonlinear vibration control and adaptive vibration control. Finally, future research directions are suggested such as nonlinear vibration of moving strings under complex constraints and couplings, energetics of nonlinear and time-varying strings, bifurcation and chaos in transverse motion of moving strings, control of hybrid systems containing moving strings, robust and adaptive controls of nonlinear moving strings, and experimental investigations. In this review article there are 242 references cited.
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Zhu, Xuezhi, Zhaobo Chen e Yinghou Jiao. "Optimizations of distributed dynamic vibration absorbers for suppressing vibrations in plates". Journal of Low Frequency Noise, Vibration and Active Control 37, n. 4 (15 agosto 2018): 1188–200. http://dx.doi.org/10.1177/1461348418794563.
Testo completoAbstract (sommario):
Dynamic vibration absorber is an ideal device for vibration control at specific frequencies. In order to get a robust vibration control performance, multiple or distributed dynamic vibration absorbers are usually used for suppressing vibrations in plate structures. Optimization methods for the single dynamic vibration absorber in various vibration systems had been proposed many years ago. However, the analytical optimization solutions with respect to the distributed dynamic vibration absorbers for the plate structures have not been found. In this paper, the optimization problems of the distributed dynamic vibration absorbers for suppressing vibrations in plates are studied. Vibration equations of the plate carrying distributed dynamic vibration absorbers are established using modal superposition method. The similarities of vibration shapes of the dynamic vibration absorbers and mode shapes of the plate are revealed. According to the characteristics of the vibration shapes of dynamic vibration absorbers, the vibration equations of the plate carrying distributed dynamic vibration absorbers are transformed into a form of equations of a two degree of freedom system. The analytical optimization formulas of the distributed dynamic vibration absorbers for suppressing vibrations in plates are derived by applying the fixed-points theory. The effectiveness of the optimization formulas is verified through numerical simulations. The simulation results also show that a brilliant multi-mode vibration control can be realized by using the optimized distributed dynamic vibration absorbers.
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Lee, Sangdeok, e Seul Jung. "Detection and control of a gyroscopically induced vibration to improve the balance of a single-wheel robot". Journal of Low Frequency Noise, Vibration and Active Control 37, n. 3 (3 luglio 2017): 443–55. http://dx.doi.org/10.1177/0263092317716075.
Testo completoAbstract (sommario):
In this article, an experimental investigation of the detection of a gyroscopically induced vibration and the balancing control performance of a single-wheel robot is presented. The balance of the single-wheel robot was intended to be maintained by virtue of the gyroscopic effect induced from a highly rotating flywheel. Since the flywheel rotates at a high speed, an asymmetrical structure of a flywheel causes an irregular rotation and becomes one of the major vibration sources. A vibration was detected and suppressed a priori before applying control algorithms to the robot. Gyroscopically induced vibrations can empirically be detected with different rotational velocities. The detection of the balancing angle of the single-wheel robot was accomplished by using an attitude and heading reference system. After identifying the vibrating frequencies, a notch filter was designed to suppress the vibration at the typical frequencies identified through experiments. A digital filter was designed and implemented in a digital signal processor(DSP) along with the control scheme for the balance control performance. The performance of the proposed method was verified by the experimental studies on the balancing control of the single-wheel robot. Experimental results confirmed that the notch filter designed following the detection of the flywheel’s vibration actually improved the balancing control performance. A half of the vibration magnitude was reduced by the proposal.
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Kim, Sang-Un, e Joo-Yong Kim. "Comparative Performance Analysis of Inverse Phase Active Vibration Cancellation Using Macro Fiber Composite (MFC) and Vibration Absorption of Silicone Gel for Vibration Reduction". Polymers 15, n. 24 (11 dicembre 2023): 4672. http://dx.doi.org/10.3390/polym15244672.
Testo completoAbstract (sommario):
This study focuses on addressing the issue of unwanted vibrations commonly encountered in various fields by designing an Active Vibration Cancellation (AVC) structure using a flexible piezoelectric composite material macro fiber composite (MFC). A comparative performance analysis was conducted between the AVC and a traditional passive gel that continuously absorbs vibrations. The results showed that AVC was more effective in mitigating vibrations, making it a promising solution for vibration control. The results of this study from extensive vibration–sensing experiments and comparisons revealed that AVC effectively cancels the vibrations and vibration absorption performance of the passive gel. These findings underline the potential of AVC as an efficient method for eliminating and managing undesired vibrations in practical applications. Specifically, AVC demonstrated a high vibration cancellation ratio of approximately 0.96 at frequencies above 10 Hz. In contrast, passive gel exhibited a relatively consistent vibration absorption ratio, approximately 0.70 to 0.75 at all tested frequencies. These quantitative findings emphasize the superior performance of AVC in reducing vibrations to levels below a certain threshold, demonstrating its efficacy for vibration control in real-world scenarios.
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YOSHITAKE, Yutaka, Ryosuke SHIMIZU, Fumitaka SHIBAHARA, Fumiya MIYAGAWA, Shuhei KAJIHARA e Akira HARADA. "308 Vibration Control Using Hula-Hoop : Vibration Control Effect and Vibration Control of Plane Motion". Proceedings of the Dynamics & Design Conference 2011 (2011): _308–1_—_308–9_. http://dx.doi.org/10.1299/jsmedmc.2011._308-1_.
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Papaspiridis, Fotis G., e I. A. Antoniadis. "Dielectric Elastomer Actuators as Elements of Active Vibration Control Systems". Advances in Science and Technology 61 (settembre 2008): 103–11. http://dx.doi.org/10.4028/www.scientific.net/ast.61.103.
Testo completoAbstract (sommario):
Dielectric elastomer actuators (DEA) are a new class of actuators, exhibiting electric field-induced strains. Upon electrical stimulation they can provide large strains and consequently electrical forces. These abilities along with their high compliance make them candidates for active vibration control. This parer presents a general framework for the usage of DEA as elements of active vibration control systems. The electrical and mechanical model of the DEA and a basic control law, for varying the voltage, is reviewed. The basic idea is to reduce the acceleration of the vibrating equipment when the system approaches its equilibrium. The application of the actuator in a single-dof-mass-spring system is modeled. The results with and without control are presented and show the large capabilities of the actuator to suppress the vibrations induced by an external force. DEA has viscoelastic properties, which can further increase the damping capabilities of the vibration absorber but on the other hand produce a time delay, which must be taken into account. Furthermore, the technological issues arisen -structure of the actuator, power and equipment needs, effect of prestrain and frequency, distributed actuation- are discussed.
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Hujare, Pravin P., e Anil D. Sahasrabudhe. "Effect of Thickness of Damping Material on Vibration Control of Structural Vibration in Constrained Layer Damping Treatment". Applied Mechanics and Materials 592-594 (luglio 2014): 2031–35. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.2031.
Testo completoAbstract (sommario):
The reduction of noise and vibration is a major requirement for performance of any vibratory system. Passive damping technology using viscoelastic materials is classically used to control vibrations. Viscoelastic material among the damping materials is widely used to dissipate the structural vibration energy. Three-layer sandwich beams, made of two elastic outer layers and a viscoelastic layer sandwiched between them, are considered as damping structural elements. This paper presents the effect of thickness of constrained damping material on modal loss factor of vibrating structures. Measurements are performed on sandwich beam structure. In order to understand the effectiveness of the sandwich structures, the dynamics of beam with constrained viscoelastic layers are investigated. Comparisons of the experimental and the Numerical results confirm that the damping levels and the natural frequencies of damped structures are well corroborated.
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Ma, Meng, Bolong Jiang, Weifeng Liu e Kuokuo Liu. "Control of Metro Train-Induced Vibrations in a Laboratory Using Periodic Piles". Sustainability 12, n. 14 (21 luglio 2020): 5871. http://dx.doi.org/10.3390/su12145871.
Testo completoAbstract (sommario):
Laboratories with sensitive instruments need a low-vibration environment. It is a challenge to control the train-induced vibration impact on these instruments when a newly planned metro line is adjacent to a laboratory building. An alternative method of mitigating train-induced ground vibrations involves installing measures along the transmission path. Recent research has highlighted the potential of periodic pile barriers with specifically designed band gaps for controlling environmental vibrations. This study performed in-situ measurements of ambient vibrations inside and outside a laboratory containing various types of sensitive instruments and located adjacent to a newly designed metro line. The vibration transfer function of the laboratory was then obtained. To help design and optimize the band gaps of periodic piles, a novel band gap performance evaluation function was proposed. Finally, numerical analysis was conducted to validate the mitigation effect of the designed periodic piles. The results showed that the band gap performance evaluation function can be used to optimize the mitigation effect of periodic piles. The proposed periodic piles clearly attenuated vibrations between 52.4 and 74.3 Hz, especially those at 63 Hz. A comparison of general vibration criteria (VC) curves revealed that vibration attenuation of one level can be obtained by the designed periodic piles.
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Ito, Atsushi, Ryosuke Tasaki, Makio Suzuki e Kazuhiko Terashima. "Analysis and Control of Pouring Ladle with Weir for Sloshing and Volume-Moving Vibration in Pouring Cut-Off Process". International Journal of Automation Technology 11, n. 4 (29 giugno 2017): 645–56. http://dx.doi.org/10.20965/ijat.2017.p0645.
Testo completoAbstract (sommario):
This paper presents analysis results of molten metal vibration for the pouring ladle of an automatic pouring system and proposes vibration suppression control during backward tilting of the ladle in the pouring cut-off process. The pouring ladle has a weir to avoid contamination of the molten metal. The weir separates the interior of the ladle into a body side and a nozzle side. First, weir effects on flow behavior are analyzed by comparing ladles with and without weirs using computational fluid dynamics simulations. In this analysis, a trapezoidal shaped input is designed as a backward tilting velocity. As a result, molten metal in the ladle with weir shows not only sloshing but also moving-volume vibration at the weir opening area. Secondly, the center points of the tilting motion are each verified by residual vibrations using FFT analysis. The frequencies of vibrating elements are nearly identical; however, analysis results show that the sloshing magnitude varies with changing center point of the tilting motion. In addition, effects of weir position and opening area on peak frequencies are analyzed. Each condition affects a frequency of moving-volume vibration. In addition, weir position changes sloshing frequencies at both body side and nozzle side of the pouring ladle. Finally, the suppression control input for each vibration is designed using the Input Shaping control approach. Design parameters for the control input were identified from residual vibrations, and assumed to be a second-order lag system. The effectiveness of the proposed suppression control input is verified by comparison with the non-controlled case.
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Zhou, Chenyang, e Yanxia Shen. "A PID Control Method Based on Internal Model Control to Suppress Vibration of the Transmission Chain of Wind Power Generation System". Energies 15, n. 16 (15 agosto 2022): 5919. http://dx.doi.org/10.3390/en15165919.
Testo completoAbstract (sommario):
Vibrations occur in the wind turbine drivetrain due to the drivetrain’s elasticity and gear clearance. Typically, the PID control method is used to suppress elastic vibration, while the method with the disturbance suppression function is used to suppress nonlinear gear clearance vibration. The purpose of this paper is to propose an equivalent PID control method based on the internal model control (IMC) for suppressing vibration caused by the wind turbine drivetrain’s elasticity and gear clearance. The equivalent PID controller can suppresses elastic vibration; the IMC controller can suppresses gear clearance vibration. First, the vibration principle of the two-mass wind turbine drivetrain with clearance is discussed. After analyzing the nonlinear characteristics of the gear clearance, the nonlinear clearance system is decomposed into a linear unit and a nonlinear bounded disturbance unit. To suppress nonlinear bounded disturbances, a disturbance suppression method based on IMC is proposed; simultaneously, an equivalent PID controller based on IMC is designed to resolve the vibration issue caused by the wind turbine drivetrain’s elasticity. The simulation experimental results show that the clearance vibration is suppressed by the original IMC method. The PID controller obtained by the IMC equivalent transformation can suppress the elastic vibration.
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Brahem, Maryam, Mnaouar Chouchane e Amira Amamou. "Active vibration control of a rotor bearing system using flexible piezoelectric patch actuators". Journal of Intelligent Material Systems and Structures 31, n. 10 (14 maggio 2020): 1284–97. http://dx.doi.org/10.1177/1045389x20916804.
Testo completoAbstract (sommario):
Rotor vibration control is crucial for the reliability of rotating machines. This article applies active vibration control to reduce the vibration of a rotor bearing system using flexible piezoelectric patches as actuators mounted on the shaft external surface. The patches reduce the vibration due to unbalance forces by generating bending moments to counteract rotor deformation. An active vibration control system is designed based on a full-state linear quadratic regulator controller. Since proximity probes are used to measure the lateral vibrations of the rotor at few shaft positions, an observer is designed to estimate the unmeasured vibrations. The weighting matrices required by the linear quadratic regulator controller are selected by trial and error so that the displacement amplitudes are reduced to a minimum and the actuation voltages remain within the limitations defined by the manufacturer of the used patches. Simulated responses demonstrate the effectiveness of the designed controller in attenuating the lateral vibration of the rotor bearing system when using two actuating voltages. The vibration response is reduced for the steady-state condition and during run-up particularly at the first critical speed.
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HIRAMOTO, Kazuhiko, e Sho SAITO. "1C13 Active/semi-active hybrid control framework for vibration control of mechanical systems(The 12th International Conference on Motion and Vibration Control)". Proceedings of the Symposium on the Motion and Vibration Control 2014.12 (2014): _1C13–1_—_1C13–10_. http://dx.doi.org/10.1299/jsmemovic.2014.12._1c13-1_.
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Cai, Xiaopei, Dacheng Li, Yanrong Zhang, Qian Miao e Rixin Cui. "Experimental Study on the Vibration Control Effect of Long Elastic Sleeper Track in Subways". Shock and Vibration 2018 (2018): 1–13. http://dx.doi.org/10.1155/2018/6209518.
Testo completoAbstract (sommario):
The vibration effect of urban rail transit has gained attention from both academia and the industry sector. Long Elastic Sleeper Track (LEST) is a new structure for vibration reduction which has recently been designed and applied to Chinese subways. However, little research has been devoted to its vibration reduction effect. In this study, field tests were conducted during peak transit hours on Beijing Subway Line 15 to examine the vibration reduction effects of the common ballastless track and LEST on both straight and curved sections. The results demonstrate that although LEST increases the wheel-rail vertical forces, rail vertical displacements, and rail accelerations to some extent, these effects do not threaten subway operational safety, and vibrations of track bed and tunnel wall are positively mitigated. LEST has an obvious vibration reduction effect at frequencies above 40 Hz. In straight track, the vibration of bottom of the tunnel wall measured in one-third octave bands is reduced by 10.52 dB, while the vibration at point on the tunnel wall at 1.5 m height is reduced by 9.60 dB. For the curved track, the vibrations at those two points are reduced by 9.35 dB and 8.44 dB, respectively. This indicates that LEST reduces vibrations slightly more for the straight track than for the curved track.
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Bae, Sang Geun, Jewoo Choi, Deok Shin Kang, Taehoon Hong, Dong-Eun Lee e Hyo Seon Park. "SHM-BASED PRACTICAL SAFETY EVALUATION AND VIBRATION CONTROL MODEL FOR STEEL PIPES". JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 29, n. 8 (14 novembre 2023): 729–40. http://dx.doi.org/10.3846/jcem.2023.20146.
Testo completoAbstract (sommario):
Unexpected damages or failures of steel pipes in refineries cause significant disruption to economic activity. While research has been conducted on the prevention of damage to steel pipes, no systematic methods or practical techniques for monitoring of vibrations to estimate the state of pipeline system have been reported. In this study, vibration safety evaluation model consisting of design – evaluation – control steps was developed to measure and control the vibration level during operation of the piping system of an oil refinery. The measurement location was designed by examining the structure of the pipe, and the vibration level measured at each location was compared with the allowable vibration level. Subsequently, two types of vibration reduction measures, namely, dynamic absorbers and viscous dampers, were introduced to reduce the vibration level. The effect of the application of the monitoring system was evaluated by comparing the vibration levels of the steel pipes before and after the application of the dynamic absorbers and viscous dampers. The vibrations of steel pipes in the oil refinery during operation decreased by over 50%. Upon applying the dynamic absorbers and viscous dampers, the responses of the frequency component also exhibited local and global reductions of approximately 50–80%.
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Reiterer, Michael, e Joachim Muik. "Application of Parametric Forced Tuned Solid Ball Dampers for Vibration Control of Engineering Structures". Applied Sciences 13, n. 12 (19 giugno 2023): 7283. http://dx.doi.org/10.3390/app13127283.
Testo completoAbstract (sommario):
In this paper, parametric forced tuned solid ball dampers (TSBD) are considered for vibration control of engineering structures in an untypical way. The special feature of the presented investigation is to evaluate the potential application of parametric forcing of the rolling cylindrical or spherical body in the runway for reducing the vertical vibrations of a vibration-prone main system. Typically, tuned solid ball dampers are applied to structures that are prone to horizontal vibrations only. The coupled nonlinear differential equations of motion are derived and the phenomenon of parametric resonance of the rolling body in the runway is analyzed. A criterion for avoiding parametric resonance is given to achieve the optimal damping effect of the TSBD. In the second part of the article, a method for the targeted use of parametric resonance to reduce the vertical vibrations of engineering structures is presented and verified, considering a biaxially harmonic excited pedestrian bridge. It is shown that, with a suitable choice of damper parameters, a stable vibration of the rolling body in the runway is formed over the course of the vibration despite the occurrence of parametric resonance and that the maximum vertical vibration amplitudes of the main system can be reduced up to 93%. Hence, the here presented untypical application of parametric forced TSBD for reducing the vertical forced vibrations of vibration-prone main systems could be successfully demonstrated.
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Jolly, M. R., e D. L. Margolis. "Regenerative Systems for Vibration Control". Journal of Vibration and Acoustics 119, n. 2 (1 aprile 1997): 208–15. http://dx.doi.org/10.1115/1.2889705.
Testo completoAbstract (sommario):
The potential for energy regeneration in vibration control systems is investigated. Such control systems hold the possibility of self-sustainability by alternately extracting and releasing energy originating from the vibrating system in a controlled non-passive manner. To be self-sustaining, more energy must on average flow into the control system than flows out. Generally speaking, the performance of such a system will approach that of an active system while theoretically requiring no externally supplied power. As research progresses in this area, an increasing number of viable applications for regenerative vibration control systems are being uncovered. This paper examines two broad applications: base-excited suspensions and periodically excited compound mounts. Some experimental results of the former are presented to support our claims.
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Hathout, J. P., e A. El-Shafei. "PI Control of HSFDs for Active Control of Rotor-Bearing Systems". Journal of Engineering for Gas Turbines and Power 119, n. 3 (1 luglio 1997): 658–67. http://dx.doi.org/10.1115/1.2817035.
Testo completoAbstract (sommario):
This paper describes the proportional integral (PI) control of hybrid squeeze film dampers (HSFDS) for active control of rotor vibrations. Recently it was shown that the automatically controlled HSFD based on feedback of rotor speed can be a very efficient device for active control of rotor vibration when passing through critical speeds. Although considerable effort has been put into the study of steady-state vibration control, there are few methods in the literature applicable to transient vibration control of rotor-bearing systems. Rotating machinery may experience dangerously high dynamic loading due to the sudden mass unbalance that could be associated with blade loss. Transient run-up and coast down through critical speeds when starting up or shutting down rotating machinery induces excessive bearing loads at criticals. In this paper, PI control is proposed as a regulator for the HSFD system to attenuate transient vibration for both sudden unbalance and transient runup through critical speeds. A complete mathematical model of this closed-loop system is simulated on a digital computer. Results show an overall enhanced behavior for the closed-loop rotor system. Gain scheduling of both the integral gain and the reference input is incorporated into the closed-loop system with the PI regulator and results in an enhanced behavior of the controlled system.
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Pla, Frederic G., e Harindra Rajiyah. "Active vibration control of structures undergoing bending vibrations". Journal of the Acoustical Society of America 99, n. 4 (1996): 1819. http://dx.doi.org/10.1121/1.415344.
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SU, Dongxu, Kimihiko NAKANO, Rencheng ZHENG e Matthew P. CARTMELL. "2A23 Stiffness tunable nonlinear vibrational energy harvester with damping control(The 12th International Conference on Motion and Vibration Control)". Proceedings of the Symposium on the Motion and Vibration Control 2014.12 (2014): _2A23–1_—_2A23–9_. http://dx.doi.org/10.1299/jsmemovic.2014.12._2a23-1_.
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