Change Of Vibration Amplitude Research Articles

Numerical simulation and experimental study of fluid–structure interactions in elastic structures based on the SPH method

The study of fluid–structure interactions in elastic structures is highly important in hydraulic structural engineering. This paper adopts the smooth particle hydrodynamics (SPH) coupling method to simulate dam failure water impact elastic plate flow and solid coupling problems. In addition, a numerical simulation is performed on the study of the free surface flow impact of the elastic plate structure on the main dynamic characteristics, including the impact force distribution and the change process. Additionally, the elastic structure of the vibration amplitude and frequency change rule, as well as the drastic changes in free surface flow, are also carried out. In this paper, the synchronous finite element algorithm is used to analyze the problem to obtain FEM results Additionally, two-dimensional benchmark physical tests are designed for dam-break water flow impacting an elastic plate are conducted, focusing on a comparative analysis of the numerical results of the SPH method with the results of physical tests and verifying the validity, accuracy, and superiority of the SPH coupling method for solving the problem of fluid‒solid coupling in elastic structures. On this basis, to explore the relevant physical quantities that cannot be measured or described during the test process, the flow–solid coupling characteristics of the elastic plate impacted by water flow are further understood by analyzing the nature of the flow field, the change in the flow–solid force of the elastic plate and the change rule of the frequency spectrum. The results show the following: (i) The jumps in velocity between the streams and the strong curvature of the free liquid surface lead to the creation of vortices at the cavities. (ii) The flow solid force under the impact of water flow increases and then decreases, and the smaller the deformation of the elastic structure is, the greater the force is. (iii) The vibration frequency of the fixed end of the elastic structure gradually decreases along the free end frequency, and the larger the deformation of the free end of the elastic plate is, the weaker its vibration response is. In addition, the natural frequency of the elastic plate under water flow impact is slightly lower than that under free vibration of the elastic plate. The related research results provide reference and guidance for the fluid–structure interaction problem.

Nonlinear dynamic modelling and analysis of a rotating composite thin-walled beam considering ice coating

For rotating structures operating in severe weather conditions, ice coating phenomenon is an established issue that impairs the reliability and effectiveness of the structures by changing the dynamic behaviors. To explore the influence mechanisms of ice coating on the dynamic behaviors of rotating structures, this work presents an analytical dynamic model for nonlinear forced vibration of a composite thin-walled beam under both rotating and ice coating conditions. The ice coating is considered as C-shaped configuration which can affect the system parameters of the beam, especially aerodynamic performance. With effect of out-of-plane warping taken into account, the nonlinear dynamic equation of the beam is established using Hamilton's principle. The Galerkin discrete method together with the incremental harmonic balance method (IHB) as well as pseudo arclength continuation technique are adopted to obtain the periodic response of the nonlinear system. Then, a detailed parametric study on natural frequency, frequency-response and bifurcation behaviors is numerically conducted. Special attention is paid to the effects of ice coating, rotating angular velocity, inflow velocity and design parameters on the linear and nonlinear dynamic behaviors of the beam. Results reveal a prominent change in natural frequency, vibration amplitude and cusp bifurcation of multivalued region under the combined effects of ice coating and rotating motion. Such ice-induced changes exhibit the requirement of vibration control and optimization design consideration for rotating structures operating in icing coating conditions.

Dynamics model and vibrational response analysis of helical gear-rotor-bearing transmission system

As a core component of wind turbines, wind power gear speed increasers often work in harsh environments, so it is necessary to study the vibration characteristics of gear transmission systems. Taking a wind turbine gearbox high-speed stage helical gear transmission system as the research object, the dynamics model of multi-degree-of-freedom helical gear-rotor-bearing transmission system is established by the lumped parameter method and solved by Runge-Kutta method, taking into account the tooth side clearance of the gear, transmission error, eccentricity and support force of the nonlinear bearing. The effects of input torque, transmission error and tooth side clearance on the vibration characteristic response of the helical gear train were analyzed. The relationship between the trend of amplitude change in each direction of the gear and the trend of change in the major frequency components was analyzed under the conditions of changing internal and external excitation. The results show that torsional vibration dominates in the system. As the input torque increases, the vibration amplitude of the driving and driven gears decreases, and the frequency amplitude decreases significantly at multiple locations. Gear transmission errors and changes in tooth side clearance have significant effects on gear vibration amplitudes, but are sensitive only to the meshing frequency. The trend of gear vibration amplitude caused by the change of external excitation of the gear set is synchronized with the trend of main frequency amplitude in the corresponding direction, while the change of vibration amplitude caused by internal excitation is consistent with the trend of mesh frequency amplitude in the corresponding direction. The results of this paper can pave a certain foundation for the design and fault diagnosis of wind power gearbox transmission system.

Modeling the effects of external oscillations on mucus clearance in obstructed airways.

Various therapeutic methods are employed to facilitate the clearance of secretions accumulated in the respiratory tracts of individuals with lower respiratory tract disorders. High-frequency chest wall oscillation (HFCWO) device, designed to apply variable amplitude and frequency vibrations to the individuals' chests, stands out among these therapies. In this study, the effectiveness of this treatment method was investigated numerically using computational fluid dynamics (CFD) on the generated mucus-obstructed bronchial geometry. The conducted analyses compared the effects of vibrations acting in the axial, radial, and tangential directions on the clearance of mucus, which exhibits non-Newtonian flow behavior with shear-thinning properties. Simultaneously, the effects of changes in vibration amplitude and frequency, pressure differentials, fluid properties, and ciliary movements on the flow were separately examined and interpreted. The findings demonstrate that ciliary movements are insufficient in mucus-accumulated airways, applied vibrations enhance mucus clearance, and potential improvements in flow are quite sensitive to boundary conditions.

Design and Analysis of Electromagnetic Linear Actuation-Energy-Reclaiming Device Applied to a New-Type Energy-Reclaiming Suspension

In order to meet the increasing demand for high-performance and high-efficiency vehicles, this paper proposes a novel electromagnetic linear energy-reclaiming suspension technology based on the McPherson independent suspension, and analyzes its core component—ELA-ERD (Electromagnetic Linear Actuation Energy-Reclaiming Device). ELA-ERD, taking a shock absorber piston rod as the inner yoke, has a compact structure and reasonable layout by integrating the structural features of the suspension. In this paper, the design process of ELA-ERD is elaborated in detail. Aiming at the problem of over-saturation of the inner yoke magnetic density, this paper proposes a method to optimize the magnetic circuit by increasing the size of the inner yoke within the effective working area of the moving coil, thus effectively improving the electromagnetic characteristics of ELA-ERD. Moreover, the effect and potential of energy reclaiming on ELA-ERD were studied by using finite element software. The study on the energy-reclaiming law of ELA-ERD was carried out from the perspective of the changes in vibration frequency and amplitude. In addition, the internal relationship between the energy-reclaiming voltage and the vibration velocity was revealed in this work, and the energy-reclaiming voltage coefficient Ke was defined. Through calculation of a large amount of model data, the Ke value applicable to the designed ELA-ERD in this paper was approximately set to 4.5. This study lays an important theoretical foundation for the follow-up studies.

Torsional Vibration Suppression of Electric Vehicle Power Transmission System Based on Parameter Optimization and Fuzzy Control

Background: The torsional vibration of the power transmission system has heavy effect on the ride comfort and safety of the vehicle, which has attracted plenty of research. Therefore, aiming at the torsional vibration problem of the electric vehicle power transmission system, enough study on how to suppress the torsional vibration is clearly of great benefit. Objective: The goal of the work is to explore the new method to suppress the torsional vibration. The main contribution is that the parameter of the power transmission system is optimized and the adaptive fuzzy PID controller is proposed to be utilized and optimized to suppress the torsional vibration. Methods: An optimization objective function including the angular acceleration of the motor shaft, the decelerator and differential assembly and the half shaft is established as the output of the genetic algorithm fitness value. The error combination of the square root of the angular acceleration of the motor shaft, the decelerator and differential assembly and the half shaft is adopted as the input of the fuzzy inference controller and the PID controller, which can significantly simplify the fuzzy rule and the structure of the controllers. Results: The proposed method significantly reduces the torque amplitude of the motor shaft, the decelerator and differential assembly, the transmission half shaft, and the overall vibration amplitude. The maximum reduced vibration amplitude change is up to 41.22% and 87.04% respectively after parameter optimization and fuzzy PID control in the example. Conclusion: The comprehensive utilization of parameter optimization and adaptive fuzzy PID control can successfully suppress the torsional vibration phenomenon of the power transmission system, and the torsional amplitude of the angular velocity and angular acceleration decreases significantly. Therefore, the vehicle noise can be reduced and the stability can be improved. The study lays a foundation for solving the torsional vibration problem and the mechanical optimal design of the vehicle transmission system.

Numerical investigation on two-degree-of-freedom vortex-induced vibration of a circular cylinder in power-law fluids

Abstract In this paper, the two-degree-of-freedom (2DOF) vortex-induced vibration (VIV) of a circular cylinder in shear-thinning and shear-thickening non-Newtonian power-law fluids are numerically investigated. A virtual spring-damper-mass system is employed to predict the VIV of the cylinder. A comprehensive analysis is conducted to study the influence of dimensionless parameters, including reduced velocity ( 3 ≤ U r ≤ 12 ) and power-law index ( 0.4 ≤ n ≤ 1.8 ) at a low Reynolds number ( R e = 150 ) and low mass ratio ( m r = 2 ) on the vortex shedding pattern, displacement frequencies, local apparent viscosity, friction coefficient, trajectories of the displacements, drag and lift coefficients, and the cylinder displacements. The results indicate that the apparent viscosity and the natural frequency of the system have a substantial effect on the characteristics of the VIV of the cylinder. By changing the values of the reduced velocity, various vortex shedding patterns such as 2S, 2P, S + P, and complex modes are observed for the non- Newtonian fluids, and several motion trajectories other than the typical figure “8″ are analyzed. By increasing the power-law index, the range of the lock-in region and the corresponding reduced velocity of the maximum transverse vibration amplitude change.

Towards a Hybrid Mass Sensing System by Combining a QCM Mass Sensor With a 3-DOF Mode Localized Coupled Resonator Stiffness Sensor

This paper describes a hybrid mass sensing system comprising a QCM (quartz crystal microbalance) mass sensor operating under atmospheric pressure and a 3-DOF mode localized coupled resonator operating in vacuum. Nanoparticles as consecutive mass perturbations are added onto the QCM, the output signals with respect to the amount of mass change are then being manipulated to generate electrostatic forces. Subsequently, the electrostatic forces act on the 3-DOF mode localized coupled resonator as external stiffness perturbations. The output metrics of the hybrid system were defined as: the resonant frequency shifts, vibration amplitude changes, and the changes in resonance amplitude ratio. Measured data was analyzed for these metrics and compared. This work demonstrated that the proposed hybrid mass sensing system attained a 2.5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> N(m · kg)-1 mass to stiffness transduction factor, and has the potential to be employed as a direct liquid contact biochemical transducer.

Blade Crack Detection using Blade Tip Timing

The harsh working environment of compressor threats the integrality of bladed disk. Crack is one of the most fatal faults of rotating blades. Detecting the crack of blades at early stage could ensure the safe operation of gas turbine and save economic costs. Blade tip timing (BTT) is a noncontact blade vibration measurement technique, which is widely used in recent years. In this article, a procedure of crack detection using BTT data is proposed. First, some typical parameters are taken into consideration, including resonance frequency, amplitude change of natural frequency, amplitude of blade tip, phase, and interblade spacing. It has been found that the frequency of the blade will decrease with the increment of crack length and reduction of crack height. In addition, the resonance frequency of the bladed disk will split when the blade cracks. The amplitude of different orders of resonance frequency varies with cracks. The amplitude of the first order changes very slightly, whereas the second and third orders are relatively obvious. The blade tip vibration amplitude and phase change with cracks without obvious regularity. The interblade distance will change due to the appearance of cracks. According to the above rules, the frequency and the interblade distance are adopted as crack diagnosis indicators. First, we use the Lomb-Scargle periodogram to quickly determine whether the crack appears and then use the blade frequency and interblade distance to locate the number of the blade having crack. In the experimental test, BTT data measured on a titanium bladed disk is used to verify the effectiveness of our method.

Enhancing the dissipative properties of particle dampers using rigid obstacle-grids

Particle dampers (PDs) are becoming a popular alternative to conventional damping devices due to their simple design and their ability to dissipate energy over a wide frequency range. The energy dissipation in PDs takes place due to relative motion between solid particles within the PD enclosure. The degree of relative motion depends on various parameters, especially it is highly sensitive to vibration amplitude changes. Usually, the particle size is much smaller than that of the PD enclosure which, under low forcing conditions, leads to sub-optimal momentum transfer and thereby leads to lower energy dissipation. In this work a new approach is investigated, in which a complex 3D rigid obstacle-grid is deliberately introduced inside the PD enclosure in order to overcome the shortcomings of a conventional PD. In order to better understand the influence of various dissipation mechanisms, simulations were performed. The Discrete Element Method (DEM) is used to model the interactions between the solid particles and their surroundings. In the simulations, the rigid obstacle-grid is described using a triangular surface mesh and to speed-up the collision detection process, efficient bounding volume hierarchy data structures were used. Moreover, laboratory experiments were set up to test the validity of the simulation models. The experimental setup consists of an electromagnetic shaker used to excite, via elastic elements, a clamped beam on which a PD with a rigid obstacle-grid is mounted. The obstacle-grid used in the experiments is manufactured using a Stereolithography 3D printer. Simulations and experiments were observed to be in good agreement. Moreover, the damping performance of a PD with a rigid obstacle-grid is observed to be at least twice as good as a conventional PD. Visual observations indicate that particles which would have otherwise been hardly contributing to energy dissipation, move violently due to an obstacle-grid, and hence actively participate in the energy dissipation process. Furthermore, a numerical study indicates that the obstacle-grid cell-size has a profound effect on the dissipation, allowing it to be used as an additional parameter to tune the damping performance of PDs.

On-site high-speed balancing of flexible rotor-bearing system using virtual trial unbalances at slow run

An identification algorithm is developed to execute high-speed balancing of the flexible rotor system supported on the conventional bearings, while rotating the system below its critical speed. The system is integrated with Active Magnetic Bearings (AMBs) as a suppression actuator as well as an excitation actuator. The AMB suppresses the vibration of the system and allows to introduce virtual trial unbalances to identify the orientation and magnitude of the residual unbalances present in the system. An Advanced Influence Coefficient Method (AICM) is developed that utilizes the influence coefficients obtained at high speed and unbalances identified at the low speed to effectively estimate the balance masses required for the high-speed flexible rotor balancing. The influence coefficients are required to be obtained just the once, whereas the balance masses can be estimated periodically by identifying the unbalances at low speeds. After balancing, the system can easily cross its critical speeds with less vibration. The AMB also controls abrupt change in vibration amplitude due to any uncertain faults, while operating at high speeds. Additionally, the virtual trial unbalances as a magnetic force generated through AMB reduces the mechanical effort involved in the placing of physical trial unbalances in the rotor system. This method allows on-site condition monitoring of the system periodically to reduce the impairment of high-speed machinery.

Probing optical mode hybridization in an integrated graphene nano-optomechanical system

We propose a scheme for sensitive local monitoring of mode hybridization in vertically asymmetric waveguides with a nano-optomechanical probe based on graphene. Extracting local information about mode hybridization is challenging using intensity measurements at the output or scanning optical probes over the waveguide. Transferring the information about the guided field profiles into the mechanical mode of graphene (with ultra-low-force sensitivity) using the optical gradient force allows for sensitive probing of the mode hybridization. In our proposed scheme, we estimate that a 100% change in the TE fraction of the fundamental quasi-TM waveguide mode would cause a change in the vibration amplitude of graphene on the order of 1000 pm. The limit of detection of the TE fraction is approximately 0.001. The change in the TE fraction due to index perturbations in the core and cladding can also be used for index sensing with responsivity on the order of 1000 pm change in vibration amplitude per refractive index unit and a limit of detection of 2 × 10 − 4 refractive index units. This work provides novel methods for applications in optomechanical modulation and sensing.

Research on the Dynamic Behaviors of the Jet System of Adaptive Fire-Fighting Monitors

Based on the principles of nonlinear dynamics, a dynamic model of the jet system for adaptive fire-fighting monitors was established. The influence of nonlinear fluid spring force on the dynamic model was described by the Duffing equation. Results of numerical calculation indicate that the nonlinear action of the fluid spring force leads to the nonlinear dynamic behavior of the jet system and fluid gas content, fluid pressure, excitation frequency, and excitation amplitude are the key factors affecting the dynamics of the jet system. When the excitation frequency is close to the natural frequency of the corresponding linear dynamic system, a sudden change in vibration amplitude occurs. The designed adaptive fire-fighting monitor had no multi-cycle, bifurcation, or chaos in the range of design parameters, which was consistent with the stroboscopic sampling results in the dynamic experiment of jet system. This research can provide a basis for the dynamic design and optimization of the adaptive fire-fighting monitor, and similar equipment.

Investigating the Effect of Complex Particle Shapes in Partially Liquid‐Filled Particle Dampers using Coupled DEM‐SPH Methods

AbstractThe process of energy dissipation in particle dampers (PDs) occurs mainly due to relative motion between solid particles within the damper container. The degree of relative motion between solid particles is especially sensitive to vibration amplitude changes. As the vibration amplitude decreases, less relative motion between solid particles is observed, leading to a drastic decrease in the damping performance of PDs. In this work a new approach is investigated, in which the damper contains a combination of both solid and liquid fillings, to overcome the shortcomings of a conventional PD. In order to better understand the underlying energy dissipation mechanisms a simulation model of a partially liquid‐filled particle damper with complex non‐convex shapes is set up. The liquid motion is modeled using the Smoothed Particle Hydrodynamics (SPH) method and the Discrete Element Method (DEM) is used to model the motion of solid particles. A numerical experiment is set up, where a particle damper is attached to a one degree of freedom spring‐mass‐damper system. By analysing the free response behavior of this system, the energy dissipated in various PD configurations is compared. Simulation results show more relative motion, hence more energy dissipation, in the liquid‐filled PD case than in the purely solid filled and purely liquid PD case, especially under low vibration amplitudes. Moreover, numerical studies were performed using a coupled SPH‐DEM approach to study the effect of the particle shape on the energy dissipation in liquid‐filled particle dampers.

Extraction of Features due to Breathing Crack from Vibration Response of Rotated Blades considering Tenon Connection and Shroud Contact

Cracks are common failures of aeroengine rotated blades. Online monitoring of rotated blades through their vibration to identify cracks early in various working conditions is significant for operational safety. Breathing crack is a practical form of early cracks and results in nonlinear vibration response. Tenon connection and shroud contact are common structures in aeroengine rotated blades, which can also lead blades to vibrate nonlinearly and seriously interfere online identification of early cracks. Thus, it is important to extract vibration features due to breathing crack considering these two structures. Firstly, a blade with tenon and shroud is simplified and a lumped parameter model of the bladed disk is built. Then, dry friction and coupling force on a blade are analyzed and dynamics equations of the lumped parameter model are established. Next, the stiffness of the blade trunk with a breathing crack is analyzed. Finally, the vibration response of blade trunks with the occurrence of breathing crack is analyzed in time and frequency domains by numerical simulation. Effective features due to breathing crack for online identification are extracted. 2x components of spectrums can be the criterion to judge whether breathing crack occurs. Besides, by comparing the changes in vibration amplitudes with 1x component peaks of spectrums, the cracked blade trunk can be distinguished. These findings can provide important theoretical guidance for online identification of early cracks in aeroengine rotated blades.

Study the Effect of Using Different Bearing Types on the Performance of Evaporative Cooler

An investigation of performance response of two types of bearings such as Cylindrical Roller Bearing and bush bearing on evaporative cooler driven by DC motor of 1500 r.p.m, through studying many parameters like vibration response, temperature raise, humidity, sound level and total performance. high quality 3D positions X, Y and Z, vibration sensors type (ADXL335 accelerometers) with Arduino mega 2560 that interfaced with Lab-View program were used to measure changes in vibration amplitude and frequency. Two temperature sensors of type (LM35) were used to investigate the temperature raise in the bearings also with Arduino mega 2560 that interfaced with Lab-View program. For humidity a sensor of type DHT22 was used, also, a portable device was used to measure electricity consumption, rotary speed and sound level in the bearings of evaporative cooler. By replacing bearings all the parameters above wear measured then a comparison between them were made to find the best performance and operation of these bearings. The obtained results from the experimental work have clarified and explained by tables and figures. It has been found that the vibration of evaporative cooler in X, Y and Z-directions increased by using two cylindrical roller bearings than using two of bush bearings. The temperature of cylindrical roller bearings increased When running the evaporative cooler more than bush bearings. the noise of Evaporative Cooler by using both types of Bearings was almost same but with a little Reduce by using cylindrical roller Bearings. Which means the Evaporative Cooler has better Performance by using bush bearings than using cylindrical roller bearings.

Investigating the dissipative effects of liquid-filled particle dampers using coupled DEM–SPH methods

One of the main disadvantages of solid-particle-filled dampers, generally called particle dampers (PDs), is that their performance is sensitive to vibration amplitude changes. The efficiency of PDs seems to reduce drastically with low intensity driving acceleration, especially when the acceleration level falls below that of gravity. In this paper, a new approach is investigated, in which the damper is filled with a combination of both solid and liquid fillings, in order to reduce such undesirable PD short comings. In order to quantify and understand the influence of various dissipation mechanisms, simulations were performed. The liquid motion is modeled using the smoothed particle hydrodynamics (SPH) method and the discrete element method (DEM) is used to model the motion of solid particles. In order to validate the simulation models, also a laboratory experiment was set up. This experiment consists of a damper, in this case a cylindrical acrylic container filled with spherical particles in combination with distilled water, mounted on a vertical leaf spring. By analyzing the free oscillation behavior of the leaf spring, the corresponding damper performance is characterized. The insights gained during experiments were then utilized to identify and validate the DEM and SPH models, respectively. Initially, damping behavior of dampers with solid filling and liquid filling are analyzed independent of each other. Then, these two configurations are compared with dampers with a combination of both solid and liquid fillings. In order to model solid–liquid dampers a coupled SPH–DEM approach is used. Experimental and simulation results show that dampers with a mixture of solid and liquid filling perform better than purely solid-filled or purely liquid-filled dampers, especially under low intensity driving accelerations. The main reasons behind this effect are believed to be that the solid particles with the additional hydraulic forces due to an added liquid are more agile leading to more relative motion and thereby leading to more energy dissipation. Moreover, the violent sloshing motion of the liquid through the tiny gaps, created by solid particles, also leads to more energy dissipation.

A mass sensor based on 3-DOF mode localized coupled resonator under atmospheric pressure

In this paper, for the first time, the mass sensitivity of a 3-DoF mode localized electrostatically coupled resonator is investigated and characterized under atmospheric pressure. A reversible method is used in which nanoparticles are added on and removed from one resonator of the 3-DOF coupled resonator system. Furthermore, a comparison of three mass sensitivity characterization methods was carried out: resonance frequency shift, resonance vibration amplitude change and resonance vibration amplitude ratio. MATLAB/SIMULINK and COMSOL Multiphysics models for the 3-DoF coupled resonator system are presented. The simulation results and theoretical calculations are in good agreement with the experimental data. The results show that a 3-DOF mode localized coupled resonator has potential to be employed for biosensing applications.

Monitoring blood removal failure during haemodialysis

We examined the effectiveness of using a triaxial accelerometer to detect blood removal failure during haemodialysis. Monitoring actual extracorporeal blood flow during dialysis is crucial as duration and blood flow directly affect the efficiency of dialysis. However, a sudden decline in blood flow in the extracorporeal line can occur fairly easily, resulting in blood removal failure. The general method of assessing blood removal failure involves visual monitoring of the detector pillow, but dialysis circuits without a pillow are currently being used to prevent problems such as coagulation. Therefore, we measured changes in blood flow in the feeding circuit using a triaxial accelerometer connected to the arterial side drip chamber. We observed an increase in vibration amplitude of the circuit when the actual flow was lower than the ‘settings’ value for blood flow. Therefore, a triaxial accelerometer can be used to effectively and promptly detect a divergence between ‘settings’ flow and actual flow because it can measure changes in vibration amplitude due to an obstruction or a reduction in blood flow. Thus, establishing threshold values for this amplitude can result in the triaxial accelerometer replacing the currently used pillow device for monitoring blood flow for detecting blood removal failure.

Управляемая вибрация звеньев подвижности производственного механизма

Introduction. The work subject is investigating friction characteristics of the moving surfaces of the production mechanism (PM) links including executive mechanisms (EM), and work tools (WT) of technological machines (TM) in the low-speed zone of an asynchronous motor (AM) powered from an autonomous voltage inverter (AVI) in the “AVI - AM” system. The work objective is to find a technical solution to the reduction of the friction effect in the PM links on the frequency-controlled drive (FCD) mechanical characteristics in the low- and creep-speed zone, and also, to the validation of the rated vibration feasibility of the mobile links in the PM guides under the starting-braking AM modes. Materials and Methods. To solve the research problems, the concept of bimodal AVI control that provides the formation of quasi-sinusoidal voltage for AM power supply in the “AVI - AM” system with the harmonic coefficients K u u > 8% is used. The program control of the amplitudes of the fundamental 5th and 7th harmonics of the stator current is applied. These harmonics form the fluctuating torques on the AM shaft and cause the normalized vibration of the PM links. Research Results. The justification and experimental proof of the AVI control feasibility providing a project change in the AM shaft vibration amplitude and a decrease in the effective friction coefficient of the PM moving links aiming at the elimination of the seizure of the links under the PM operation conditions are obtained. Such an effect is possible under the AM rotor spinning in the low current frequency (0.5-20 Hz) zone which is typical for the slow-speed motion of PM under the starting-braking FCD modes. Discussion and Conclusions. The application domain of the developed technical solution covers many PMs with FCD for which the short-time operation modes (with CY of 40% and more) are considered basic. Thus, the use of the effect of vibration linearization of the friction coefficient in the PM links allows the following: to reduce the AM breakaway voltage and significantly extend the FCD speed control range, to increase the ride quality and improve the PM out put link kinematics on which the WT is fixed.