Maximum Vibration Acceleration Research Articles

Novel Phononic-Like Crystal Wave Barrier Structure for Vibration Isolation

As an efficient, environmentally friendly, and economical urban public transportation tool, the subway has significant advantages compared to other urban public transportation tools and plays an irreplaceable role in the urban rail transit system. While the subway brings many conveniences to people, its operation has also brought a series of problems to urban development and residents’ lives, especially the vibration and noise problems generated by the subway have become unavoidable and urgent problems to be solved. The traditional wave barriers have a certain effect on attenuating and suppressing the vibration generated by the subway, but it has shortcomings in terms of the width and quantity of elastic wave bandgap (BG), so its application in low-frequency vibration reduction and isolation of subway systems is greatly limited. In order to broaden the elastic BG width and quantity of the wave barrier, this paper designs a novel phononic-like crystal subway wave barrier (PLCSWB) for subway vibration isolation based on locally resonant theory. Firstly, the dispersion curves of the novel PLCSWB are calculated using the improved plane wave expansion method and finite element method (FEM), and compared with the dispersion curves of traditional phononic crystal (PC) wave barriers. Secondly, the frequency response function of the novel PLCSWB is calculated using FEM to evaluate its attenuation effect on vibration, and the energy distribution characteristics at its BG boundary are analyzed. Then, the main factors affecting the BG of the novel PLCSWB are analyzed, and a spring–mass system equivalent model of the novel PLCSWB is established to theoretically estimate its BG range. Finally, the vibration data of the tunnel wall monitored on site are used to analyze and verify the vibration isolation effect of the novel PLCSWB. The results show that the novel PLCSWB opens five low-frequency BGs in the 200[Formula: see text]Hz frequency band, which increased the total width of the opened BGs by 49% compared to traditional PC wave barriers. In the frequency range of the BG, the attenuation value of the novel PLCSWB to vibration is mostly above 30[Formula: see text]dB, and the energy distribution inside the structure is mainly concentrated in the primitive cell that controls the BG, indicating good attenuation and control effects on vibration. The main factors affecting the BG of the novel PLCSWB are the density of the scatterer material, the elastic modulus, and the thickness of the wrapping layer material. Moreover, during subway operation, the novel PLCSWB has a good attenuation effect on the vibration transmitted from the tunnel wall to the soil. Among them, the maximum vibration acceleration amplitude of the novel PLCSWB with nine rows is reduced by 47%, and the vibration isolation performance is remarkable. The relevant research results of this paper provide a novel approach and method for the study of subway vibration reduction and isolation, and can also provide specific references for the design and development of wave barriers.

Analytical method for time-varying meshing stiffness and dynamic responses of modified spur gears considering pitch deviation and geometric eccentricity

Pitch deviation and geometric eccentricity are almost inevitable in gear transmission systems. Tooth profile modification (TPM) is a common method used to improve gear contact properties. However, the coupling interaction between the tooth profile deviation introduced by TPM and manufacturing errors is complex. There is a lack of an analytical model that can clarify the dynamic behaviors of the modified gear pair affected by multiple manufacturing errors, specifically pitch deviation and geometric eccentricity. To fill this gap, a comprehensive analytical gear mesh model is proposed considering TPM, pitch deviation, and geometric eccentricity. The calculation formulas for the time-varying meshing stiffness (TVMS) and load sharing factor (LSF) are derived considering the iterative change of gear pair meshing parameters with phase under the influence of multiple manufacturing errors. Then, the translation-torsion coupling dynamic model of the spur gear pair based on the lumped mass method is established to investigate the dynamic transmission error (DTE) and vibration characteristics. Results show that TPM is an effective method for improving the comprehensive stiffness of a gear pair within the meshing range containing pitch deviation, but it reduces the meshing phase that includes only geometric eccentricity. Compared with the unmodified gear pair, the suppression effect of changing the modification length on the maximum DTE and vibration acceleration is more significant than that of the modification amount. TPM increases the overall fluctuation threshold range of DTE for gear pairs with only geometric eccentricity. It is expected that the proposed method can provide a theoretical basis for exploring vibration suppression in gear pairs with geometric eccentricity and pitch deviation errors.

A method combining active control with passive regulation to enhance the vibration suppression capability of linear motor-driven aerostatic stage

The Linear Motor-Driven Aerostatic Stage (LMDAS) has been extensively applied in high-precision measuring instruments and precision equipment requiring exceptional velocity and acceleration performance. This is attributable to its low friction, high precision, and high dynamic performance. Nevertheless, the LMDAS is vulnerable to external disturbances due to weak damping of the aerostatic guideway's gas film. This weakness directly affects the positioning accuracy and dynamic characteristics of the system and results in its flutter. This paper proposed a method for improving the overall damping of the system and its ability to suppress vibrations by enhancing the damping of the driving direction via combining active control and passive regulation. The active control algorithm based on the active disturbance rejection controller and the passive regulation technology based on the linear motor were presented, respectively. Both numerical and experimental studies demonstrated that this approach was superior to the traditional PID controller, commonly employed in LMDAS, regarding steady-state performance, dynamic response, and vibration suppression. In particular, this method demonstrated a significant improvement in reducing the maximum vibration acceleration of the LMDAS in all three directions, achieving a 50 % reduction compared to the conventional PID controller.

A survey on countermeasures of railway vehicle stability decrease caused by the evolution of hollow-worn wheels

With the problem that the lateral vibration acceleration of the frame of a certain type of Electric Multiple Units (EMU) gradually approaches the limit value as the running mileage increases, the tracking test was conducted on the whole vehicle’s wheel tread wear and the frame’s vibration response. It was found that as the tread hollow-worn increased, the vehicle stability would deteriorate. In order to improve vehicle stability, an optimisation method of EMU stability is proposed based on controlling the evolution of hollow-worn wheels. The results show that after optimisation by this method, the hollow-worn state of the wheel tread is significantly improved; the equivalent conicity of the worn wheel is reduced by 16.39%, and the maximum lateral vibration acceleration of the frame is reduced by 32.02%, so the vehicle stability is also significantly improved; meanwhile, the ride comfort and safety of the vehicle still meet the requirements of the standard.

Pemetaan Tingkat Bahaya Gempabumi Berbasis Percepatan Getaran Tanah Maksimum Dan Intensitas Gempabumi Di Provinsi Bali

The Research has been carried out on the level of earthquake hazard in the Bali region based on maximum ground vibration acceleration (PGA) and earthquake intensity. The data that used in this research were obtained from the BMKG and USGS catalogs. The value of the earthquake hazard level is calculated using the appropriate PGA empirical equation through a correlation test of several empirical equations, namely the Katayama, Mc. Guire, Faccioli, Singh et al, Ambraseys, and Wang Tao with BMKG observation data.. Based on the correlation test, the Katayama equation (1974) was obtained with the smallest error value of 0.52. The calculation results show that the maximum PGA value ranges from 154-1944 gal and the earthquake intensity ranges from VII to X on the MMI scale with the highest hazard level in the Karangasem, Buleleng, and parts of Jembrana districts.

Study on the Dynamics Characteristics of HTS Maglev Train Considering the Aerodynamic Loads under Crosswinds

High-temperature Superconducting (HTS) maglev trains are vulnerable to the effects of crosswinds when operating at high speeds in open-air conditions, potentially compromising riding comfort and safety. This study established a vehicle dynamic model based on the nonlinear maglev-track relationship and added aerodynamic loads under crosswinds to the train’s simplified load center to address this issue. Using the maximum vibration acceleration limit and the Sperling index, we evaluated the riding comfort of the HTS maglev train under different conditions. Further, the vibration acceleration power spectral density was analyzed to reveal the impact of increasing the train’s operating speed and crosswind speed. The results indicated that the lateral and vertical Sperling index achieved an “excellent” rating, even at crosswind speeds of up to 20.7 m/s when the train was traveling at speeds of up to 600 km/h. However, it was noted that particular attention should be given to the riding comfort in the head car when the speed reaches 600 km/h. Moreover, the influence of the increase in train speed on the vibration frequency domain distribution of the three car bodies and the train’s riding comfort is greater than that of the increase in the crosswind speed. These findings may provide a valuable reference for the future engineering application of the HTS maglev train.

Structural response for vented hydrogen‐air deflagrations: Effects of volumetric blockage ratio

AbstractThe explosion venting experiments of hydrogen‐air premixed gas were carried out in a 1‐m3 cuboid container. The effects of the obstacles parallel to the vent on the structural response of the container during the explosion venting were investigated. The internal overpressure and acceleration of the vessel wall were captured by acceleration and pressure sensors, respectively. The time–frequency distributions of pressure and acceleration were obtained by a Short‐Time Fast Fourier Transform. The effects of obstacles on the dynamic structure response were studied by analyzing the internal overpressure, vibration acceleration, and high‐speed videos. With the increase of obstacles, the maximum overpressure and vessel vibration increased, and the maximum overpressure and maximum vibration acceleration appeared earlier. The vibration signals had two dominant frequencies, 300‐600 Hz and 900‐1200 Hz. The low‐frequency vibration (300–600 Hz) was induced by acoustic oscillation of the internal pressure. The high‐frequency vibration (900–1200 Hz) was a container resonance triggered by the coupling of the flame and the acoustic wave. As VBR increased, the duration of high‐frequency oscillations decreased gradually; the increase of obstacles would weaken the high‐frequency structural response of the container. The results can guide the design of hydrogen explosion protection and mitigation measures.

Vibration isolation characteristics of magnetorheological damper for the large wind turbine gearbox

ABSTRACT The gearbox vibration isolation theory in the large wind turbine transmission system is analyzed. The host frame is flexible, and the vibration isolation system is approximately equivalent to a two-degree-of-freedom system. According to large wind turbine gearbox isolation requirement, and a vibration isolation device of magnetorheological damper of the large wind turbine gearbox is designed, the magnetic field characteristics inside the magnetorheological damper are simulated and calculated by using COMSOL, when 0.5, 1, 1.5and 2 A currents are passed through the magnetorheological damper coil, the magnetic induction intensity of the damping gap and the output force of the magnetorheological damper are calculated, it can reach 1300N-5400N, which meets the gearbox vibration isolation requirements. It designed the on-off current control method of the magnetorheological damper. The prototype is tested on a certain type of offshore wind turbine, and the acceleration spectrum signals of the gearbox in the Z direction are collected under the working conditions of 990, 1200 and 2000 r/min. According to the collected data values, the vibration isolation characteristics of the designed magnetorheological damper are analyzed; the data show that the vibration level drop is about 20 dB, and the vibration isolation effect is good. By using the coherence coefficient method to process the measured data, the modified transfer function is obtained, which is consistent with the theoretical transfer function of the vibration model of two-degree-of-freedom system, so it is proved to be reasonable. The vibration isolation characteristics of rubber and the magnetorheological damper are compared at the rated speed, and it shows that the maximum vibration acceleration of the gearbox under the magnetorheological damper reduces from 0.375 m/s2 to 0.175 m/s2, which verify the damping effect of the magnetorheological damper.

基于模态试验的揉碎机振动特性分析

Aiming at the problems of large vibrations and noise of a working stalk rubbing machine, this paper took the 9R-60 rubbing machine as the research object and used the B&K modal test system and the vibration test system to analyse the modal and no-load conditions of the whole machine. Through analysing modal test data, it was concluded that the first five natural frequencies of the machine were 95.262 Hz, 144.386 Hz, 288.198 Hz, 313.719 Hz and 326.140 Hz. The results showed that spindle rotation had a more significant effect on the vibration than the feed chain rotation; the maximum vibration acceleration occurred at the small motor frame at a spindle speed of 1700 r·min-1 and a feed chain speed of 0.65 m·s-1, which was 135.539 m·s-2. The distribution of the amplitude statistical characteristics of the vibration signals follows the normal distribution and belongs to the stationary random process. The vibration was a self-excited vibration of the rotating machinery caused by the rotation of the main shaft and a forced vibration excited by the rotation of the same shaft. The research provides a direction for further research on the vibration characteristics of the rubbing machine under load conditions, and provides a theoretical basis for the subsequent vibration reduction design.

Analysis and optimization of seismic performance of high-rise residential building

In order to improve the seismic performance of high-rise buildings, a friction damper installation scheme was proposed in the paper. Through numerical simulation and experimental testing, the vibration reduction effect was compared and verified. Herringbone structure was applied to install friction damper in the bearing wall. Based on this vibration reduction scheme, the finite element model of high-rise building was established, and the influence of damper on the modal characteristics of building frame was analyzed. It can be known that the damper has little influence on the natural frequency, but has a great influence on the amplitude range of the excitation response. In the finite element model, two kinds of seismic waves were applied, the strength and dynamic response was simulated and calculated, and the maximum deformation and stress results were obtained. Compared with the initial model, it can be known that the more intense the vibration is, the more obvious the damping effect of the damper is. A seismic excitation simulation system based on acceleration sensor detection is designed and applied to the wall vibration test. The results show that the maximum vibration acceleration of the measured point is reduced by 26.3 % by the damper, and the stable seismic effect can still be maintained during the impact of extension. Compared with the traditional hardness and volume reinforcement scheme, the friction damper can reduce the production cost and improve the adaptability to seismic wave excitation, which provides an important basis for seismic research in other fields.

Analisis Percepatan Getaran Tanah Maksimum Untuk Memetakan Kerawanan Bencana Gempa Bumi dengan Metode Fukushima-Tanaka, Esteva dan Euclidean Distance di Pulau Lombok

Lombok island is a small area located on the border between the large Asian plate and the Autralian plate so that the islan of Lombok is verry vulnerable to the earthquake disasters. The level of damage caused by an earthquake depends on the strength and quality of the building, geological, and geotechtonic conditions and the maximum ground vibration acceleration of the area. This study aims to analyze the acceleration of ground vibrations to map earthquake vulnerability using the Fukushima Tanaka, Esteva, and Euclidean Distance methods on the island of Lombok. The data used is secondary data for earthquakes on the island of Lombok in Juli-September 2018. The calculation result show that the maximum ground vibration acceleration value is the highest of 100.810 gal located in the districts of EastbLombok and North Lombok. While the smallestmaximum ground vibrations acceleration value occurs in the Mataram and surrounding areas with a value of 0,3603 gal. From the three formulations, it can be seen that the value of ground vibration acceleration calculated in the area of the island of Lombok using the Fukushima Tanaka method is the most appropriate formula for calculating the value of ground accelaration on the Lombok island. That is because the value of the ground vibration acceleration from Fukushima Tanaka is almost the same as the ground vibration acceleration value from the accelerograph

Experimental analysis of steering wheel vibrations of an agriculture tractor for reduction of hand-arm vibrations

Steering wheel vibration is one of the most important factors in determining the operator comfort in agricultural tractors. It is important to investigate steering wheel vibrations in an agricultural tractor in order to improve the operator’s comfort and decrease the negative health impacts on the operator’s hand. The Mahindra 575 DI tractor was selected for further investigation and development as the maximum vibration acceleration was found in the Mahindra 575 DI tractor while measuring the amplitude of vibration on various tractors. The experimental test setup was designed with a solution to reduce steering wheel vibrations. The experimental analysis of steering wheel vibration of an agriculture tractor for the reduction of Hand-Arm Vibration Syndrome (HAVS) is presented in this research article. The vibration level was decreased effectively after establishing a tuned mass damper between the steering gearbox and the vibration exciter.

A vertical coupling dynamic analysis method and engineering application of vehicle–track–substructure based on forced vibration

PurposeThis study aims to propose a vertical coupling dynamic analysis method of vehicle–track–substructure based on forced vibration and use this method to analyze the influence on the dynamic response of track and vehicle caused by local fastener failure.Design/methodology/approachThe track and substructure are decomposed into the rail subsystem and substructure subsystem, in which the rail subsystem is composed of two layers of nodes corresponding to the upper rail and the lower fastener. The rail is treated as a continuous beam with elastic discrete point supports, and spring-damping elements are used to simulate the constraints between rail and fastener. Forced displacement and forced velocity are used to deal with the effect of the substructure on the rail system, while the external load is used to deal with the reverse effect. The fastener failure is simulated with the methods that cancel the forced vibration transmission, namely take no account of the substructure–rail interaction at that position.FindingsThe dynamic characteristics of the infrastructure with local diseases can be accurately calculated by using the proposed method. Local fastener failure will slightly affect the vibration of substructure and carbody, but it will significantly intensify the vibration response between wheel and rail. The maximum vertical displacement and the maximum vertical vibration acceleration of rail is 2.94 times and 2.97 times the normal value, respectively, under the train speed of 350 km·h−1. At the same time, the maximum wheel–rail force and wheel load reduction rate increase by 22.0 and 50.2%, respectively, from the normal value.Originality/valueThis method can better reveal the local vibration conditions of the rail and easily simulate the influence of various defects on the dynamic response of the coupling system.

A multi-objective optimisation method of rail combination profile in high-speed turnout switch panel

This paper presents a multi-objective optimisation method considering the switch and stock rail profiles in the switch panel. Based on the non-uniform rational B-spline (NURBS) theory, a parameterised model of the measured turnout profile is constructed to determine the variables. This study selects the vehicle dynamic performance and wheel-rail contact damage as the objective function to establish a multi-objective optimisation mathematical model that is solved using NSGA-II. Overall performances of the measured profile and the optimised profile are compared and evaluated for two aspects, dynamic performance and wheel-rail contact damage. The following are the conclusions: The maximum lateral vibration acceleration of the axle box is reduced from 2.64–2.09 m/s2, which has a 20.83% decrease. Concerning wheel-rail contact damage, the maximum wear index is reduced from 13.46–11.47 N, the reduction is 14.78%. At the same time, the cumulative surface rolling contact fatigue (RCF) is reduced from 8.29×10−5–7.38×10−5. This article can provide a profile repair method for worn turnouts, which can maximise the comprehensive performance of the turnout within a limited amount of grinding, and can reduce the wheel-rail contact damage of the turnout while taking into account driving stability.

Study of the external section shape of the static characteristic of the antivibration suspension with a quasi-zero stiffness section

The paper considers the vibration isolation problem of the construction and road vehicles operator’s seat with prescribed sinusoidal displacements of the seat base. This problem is highly relevant, since the road construction vehicles operation with soil, loads, road surfaces, etc. is accompanied by the strong vibrations. The investigation was carried out in terms of the influence of the suspension static power characteristic shape on the maximum vibration acceleration of the seat. Many antivibration mechanisms have a similar static characteristic. Currently, one of the promising directions in the development of the antivibration systems is the implementation of the systems with a quasi-zero stiffness section of the static power characteristic. Such systems are preferred to dampen the low-frequency vibrations. In this paper, we study the systems having a three-segment static characteristic, which middle segment is a horizontal straight line corresponding to a section of quasi-zero stiffness. However, two extreme segments providing the braking and stopping of the mechanism when going beyond the boundaries of the quasi-zero stiffness section were described by Hermite splines with a maximum second-order derivative. The analytical expression of such a two-point spline makes it possible to set not only the function values at two boundary points, but also the values of the first two derivatives of this function at the same points, i.e. to vary the shape of such spline within a wide range. This has made it possible to consider several dozen combinations of such splines having different values of the first derivative at both boundary points, i.e. to study the differently shaped static power characteristics of the antivibration mechanism of the seat under the same sinusoidal influences. The sum of accelerations calculated for a sample of the specified seat base vibrations from the amplitude and time values combinations was used as the assessment and evaluation criterion of various static power characteristics. Furthermore, the amplitude and time values combinations, at which the maximum value of the antivibration mechanism displacements exceeded the limits of at least one of the static characteristics, were excluded from consideration and were not taken into account when calculating the criterion values. The criterion minimum value was found out to be reached at zero value of the first force derivative at the internal boundary points of the external characteristic segments, at the maximum value of the first force derivative at the external boundary points of the external characteristic segments. In this case, the first force derivative has no discontinuities on the entire static force characteristic curve. The given static characteristic is optimal according to the accepted criterion. The value of the acceleration sum criterion can be decreased fourfold in the studied range of the first derivatives from zero to twenty thousand Newton/meter.

Aerodynamic loads and bridge responses under train passage: case study of an overpass steel box-girder cable-stayed bridge

Increased train speeds have led to significant train-induced wind problems. This paper describes a numerical study of the aerodynamic loads produced when a train passes under a bridge and the bridge dynamic response based on a steel box-girder cable-stayed bridge. The results indicate that the wind pressure on the bottom plate and the maximum lift on the beam sections increase as the train speed increases or as the clearance under the bridge decreases. Changes in the intersection angle are found to have a greater impact on the 1/4-span and 3/4-span regions. The effects of the various influencing factors are basically the same in the construction and operation stages. As the train speed increases or the clearance under the bridge decreases, the bridge responses exhibit an upward trend. As the intersection angle decreases, the vibration displacement tends to increase, but the effects on the vibration acceleration and maximum counter-force of the temporary pier are not consistent. Compared with the construction stage, the dynamic responses of the main girder are smaller in the operation stage due to the larger overall rigidity and the support constraints. In the parameter ranges investigated in this study, the absolute values of maximum vertical bridge vibration displacement and acceleration decrease from 4 to 16 mm and from 85 to 400 mm/s2, respectively, in the construction stage to 1–5 mm and 42–174 mm/s2 in the operation stage. Moreover, the counter-force falling on the temporary pier after the main girder turns does not exceed the 2000-kN positive force or 300-kN negative force limits. In the operation stage, the bridge vibration responses will not affect the comfort of pedestrians.

Analysis of the Influence of Transmission Housing Elasticity on the Vibration Characteristics of Gear Shafting under Coupling Effect

The influences of transmission housing elastic deformations on the vibration gear shafting characteristics are studied. The vibration model of the vehicle transmission system in consideration of the dynamics coupling of the housing and the gear shafting is constructed. Aiming at a vehicle transmission, the mathematical model of the bending and torsional gear shafting vibrations is established based on the lumped mass method. Following the elastic treatment of the box, a comprehensive stiffness model at the bearing considering the housing deformation is proposed to achieve the dynamic coupling between the box and the gear shafting system. Furthermore, the gear shafting vibration characteristics considering housing deformations are obtained by integrating multisource dynamic excitation, which is solved using an iterative method. The results are verified through a bench test. And, it shows that the elastic deformation of the housing aggravates the gear shafting vibration (bending and torsional coupled vibration). The peak frequency mostly remains the same. The maximum speed changes amplitude and associated root mean square value (calculated at the gear position) increase by 55.5% and 59.6%, respectively. Next, the maximum bearing support force and its root mean square value are increased by 63.7% and 97.6%, respectively. Finally, the largest increase in maximum vibration acceleration at the measuring point and the simulated root mean square value are 90% and 63.1%, respectively. It is concluded that the research results provide a theoretical basis for the study of transmission dynamic reliability.

Horizontal vibration response analysis of ultra-high-speed elevators by considering the effect of wind load on buildings

Abstract. At present, the wind-induced vibration effects of super-high-rise buildings caused by wind loads can no longer be ignored. The wind-induced vibration effect of super-high-rise buildings will inevitably cause the vibration of ultra-high-speed elevators. However, for the study of the vibration characteristics of ultra-high-speed elevators, the wind-induced vibration effect of the ultra-high-speed elevator is often ignored. Based on Bernoulli–Euler theory, the forced vibration differential equation of elevator guide rail was established, and the vibration equation of elevator guide shoe and car was established by using the Darren Bell principle. The coupled vibration model of the guide rail, guide shoes, and car can be obtained through the relationship of force and relative displacement among these components. Based on the model, the effects of wind pressure and building height on the horizontal vibration of the ultra-high-speed guideway and passenger comfort were analyzed. The results showed that the influence of the wind load on the vibration of ultra-high-speed elevator can no longer be disregarded, and the maximum horizontal vibration acceleration of the guide rail is positively correlated with the height of building. The vibration acceleration of the same height rail increases with the increase in wind pressure. The vibration dose values (VDVs) increase with the increase in wind pressure and building height, respectively.

Research on high-temperature vibration measurement method using laser Doppler interferometry

High-temperature vibration measurement plays a critical role in the design and performance testing of equipment such as aero-engine and heavy-duty gas turbines. Due to its non-contact, high accuracy, and resolution, the laser Doppler method has become one of the most commonly used vibration measurement techniques. However, one of the main problems in high-temperature vibration measurement is that the surface of the measured objects is oxidized, thus resulting in a decrease of interference signal intensity and signal-to-noise ratio. Furthermore, the aforementioned may even cause measurement failure. In this paper, an all-fiber laser Doppler velocity measurement device using a fiber optic circulator is established. Its vibration measurement performance is experimentally validated at high temperatures. The results demonstrate that this device can achieve vibration measurement within the temperature range of 300°C-1200°C with a maximum vibration speed of 1 m/s and maximum vibration acceleration of 378.4 m/s2. Relative deviation with Polytec vibrometer’s velocity results is within 1.95%. This model provides a viable solution for achieving accurate measurements of high-temperature vibration.

Analysis and design of electromagnetic vibration and noise reduction method of permanent magnet motor

Vibration and noise parameters have a significant influence on the performance of permanent magnet motor (PMM). A new method of reducing vibration and noise of PMM was proposed in this study by optimizing the stator teeth profile. The optimal offset distance was determined by finite element method, and the results indicate that the vibration and noise amplitude become larger when the frequency is an even multiple of the fundamental frequency. The maximum and average vibration acceleration of the optimized PMM is reduced by 22.27% and 11.11%, respectively, and the total sound pressure level (SPL) is decreased by 3.67%. Finally, the correctness of the theoretical parameters was verified by the vibration and noise measuring experiment. The experimental data suggest that the average acceleration error is 7.07%, and the average SPL error is 2.28%. The research methods and conclusions of this study may be extended to the vibration and noise optimization of other PMM.