scholarly journals Research on Vibration Reduction Characteristics of Continuum and Noncontinuum System on Coupling for High-Power Gear Transmission Based on Particle Damping Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wangqiang Xiao ◽  
Zhanhao Xu ◽  
Sheng Wang ◽  
Shaowei Yu ◽  
Kai Qin ◽  
...  
Keyword(s):  
High Power ◽  
Vibration Reduction ◽  
Transmission Error ◽  
Gear Transmission ◽  
Analysis Model ◽  
Filling Rate ◽  
Element Analysis ◽  
Displacement Mapping ◽  
Reduction Effect ◽  
Damping Materials

High-power gears are widely used in various engineering fields. The gear transmission system is an extremely complex elastic system, which produces complex vibration under internal and external excitation. For the vibration and noise problems caused by transmission error, a discrete element and finite coupling method based on the particle filling rate is proposed. Firstly, the gear dynamic model was established, and the particle damper was installed in the gear to reduce the vibration of the gear. Secondly, through the coupling process, the contact force and contact position between the noncontinuous medium and the continuous medium were correctly transferred to the corresponding nodes of the finite element analysis model. Then, the equivalent displacement mapping of the contact loads’ node of the gear was realized, and the transformation of the local coordinate to the global coordinate was carried out. Finally, by combining theoretical analysis with experimental verification, the influence of the filling rate of damping particles on the vibration reduction effect of the gearbox under different working conditions was studied. The 2 mm tungsten particles were selected, and the particle damper had the best damping effect when the filling rate was 88%.

scholarly journals Simulation Study on the Blocking Effect and Vibration Reduction Characteristics of Acoustic Black Hole in Thin Plate

2020 ◽  
Vol 6 (4) ◽  
pp. 223-231
Author(s):  
Z. Liu ◽  
Y. Zhou ◽  
A. Golyanin
Keyword(s):  
Finite Element ◽  
Black Hole ◽  
Noise Reduction ◽  
Thin Plate ◽  
Vibration Reduction ◽  
Structural Vibration ◽  
Energy Concentration ◽  
Element Analysis ◽  
Finite Element Software ◽  
Reduction Effect

Recently, more and more scholars have devoted themselves to researching new methods of vibration reduction and noise reduction by manipulating the elastic waves in the structure to achieve the purpose of vibration reduction and noise reduction. To this end, a new type of ‘acoustic black hole’ structure is proposed, which reduces structural vibration while avoiding problems such as mass increase. In this paper, the vibration damping performance of the structure is mainly calculated by finite element software, and the energy concentration effect of the thin plate containing the acoustic black hole is verified by finite element analysis. A thin plate structure with four acoustic black holes is proposed. The calculation shows that the structure has obvious vibration reduction effect, and the vibration reduction effect can reach more than 20dB at high frequency.

A cyclic symmetric model for the investigation of vibration reduction of hard-coating blisk

2020 ◽  
Vol 37 (9) ◽  
pp. 3387-3406
Author(s):  
Wei Sun ◽  
Shuai Yang ◽  
Junnan Gao ◽  
Xianfei Yan
Keyword(s):  
Coating Thickness ◽  
Vibration Reduction ◽  
Hard Coating ◽  
Symmetric Model ◽  
Cyclic Symmetry ◽  
Frequency Range ◽  
Analysis Model ◽  
Content Type ◽  
Cyclic Symmetric ◽  
Reduction Effect

Purpose It is very important to create a useful cyclic symmetric model for the investigation of the vibration reduction effect of hard-coating blisk. This study aims to develop a cyclic symmetry algorithm which can determine the mode of blisk in the sector coordinate system directly. Design/methodology/approach Using the exponential and real quasi-equivalent Fourier matrices, the formulas for solving the sector mode were derived, and the relationship between the two kinds of sector modes was also discussed. Based on the proposed cyclic symmetry algorithm, the vibration characteristics of an academic blisk were solved, and the formulas for solving the natural characteristics and vibration responses of the coated blisk were given. Findings A blisk with NiCrAlCoY+YSZ hard coating on both sides of each blade was chosen as a case to demonstrate the presented method. Based on the verification analysis model, the influences of coating thickness on the vibration reduction effect of the blisk were discussed. The results show that the hard coating has good vibration reduction effect on the blisk even the coating thickness is very thin and the vibration reduction effect of hard coating in the high frequency range is obviously better than that in the low frequency range. Originality/value As a large number of reduced order modeling methods of blisk are implemented based on the sector modes, the proposed method which can obtain the sector modes directly will significantly improve the efficiency of dynamic modeling and analysis of the coated blisk structure.

Design of a particle damper and experimental study on vibration damping of the pipeline

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110449
Author(s):  
Gen Jin ◽  
Zihao Zhao ◽  
Binbin Liu ◽  
Wenyuan Cun ◽  
Zhengda Zhao ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Vibration Reduction ◽  
Particle Energy ◽  
Test Results ◽  
Filling Rate ◽  
Promising Application ◽  
Maximum Particle ◽  
Reduction Effect ◽  
Pipeline Vibration ◽  
The Impact

In this work, we designed a particle damper which can be conveniently clamped on to a pipeline without affecting the existing structure, showing a promising application in vibration reduction of real aircraft. Based on the designed particle damper, the impact of particle filling rate on the vibration reduction effect, the effect of EDEM simulation on the energy consumption of particles in the vibration process of the damper, and the result of actual vibration reduction test of particle damper installed on hydraulic pipeline were investigated. It is found that the vibration of the pipeline decreases first and then increases with the increase of particle filling rate. The particle filling rate corresponding to the maximum particle energy consumption rate is consistent with that of the minimum pipeline vibration acceleration during the test, that is, from 94.9% to 97.9%. The simulation results are in good agreement with the test results. Moreover, the vibration of the hydraulic pipeline and actual aircraft pipeline are both obviously suppressed after the installation of the particle damper. These results fully demonstrate the effectiveness and practicability of the aircraft pipeline particle damper.

Research on Vibration Reduction Mechanism for Robot Joints by Imitating the Owl Surface Characteristics

2014 ◽  
Vol 539 ◽  
pp. 13-17
Author(s):  
Shao Ming Sun ◽  
Dong Sen Ye ◽  
Xuan Wu
Keyword(s):  
Vibration Reduction ◽  
Surface Characteristics ◽  
Structure And Function ◽  
Reduction Mechanism ◽  
Element Analysis ◽  
Vibration Problems ◽  
Reduction Effect ◽  
Solid Works ◽  
Joint Vibration ◽  
And Function

On the base of bionics and mechanics of vibration, the mechanism of the structure and function of robot joint vibration reduction was researched for more and more prominent vibration problems in the design of the robot. Drawing the model by Solid works and making finite element analysis (FEA) by Abaqus, vibration frequency was analyzed on different condition, exploring the influence of vibration of robot joint with and without package coatings as well as with and without holes in the package coatings. The experiment and simulation result showed that vibration reduction effect was obvious in robot joint covering package coatings with high punching rate.

Performance analysis of magnetic gear with Halbach array for high power and high speed

2020 ◽  
Vol 64 (1-4) ◽  
pp. 959-967
Author(s):  
Se-Yeong Kim ◽  
Tae-Woo Lee ◽  
Yon-Do Chun ◽  
Do-Kwan Hong
Keyword(s):  
Permanent Magnet ◽  
Eddy Current ◽  
High Power ◽  
High Speed ◽  
Torque Ripple ◽  
Eddy Current Loss ◽  
Element Analysis ◽  
Current Loss ◽  
Halbach Array ◽  
Magnetic Gear

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.

Modeling and experimental verification on directivity of an electret cell array loudspeaker

2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Digital Control System ◽  
Analysis Model ◽  
Cell Array ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
The Finite Element Analysis ◽  
Directivity Characteristics

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.

scholarly journals Wellbore trajectory control tool seal system leakage analysis based on steady gap flow

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402093046 ◽  
Author(s):  
Lei Shi ◽  
Keqiang Wang ◽  
Ding Feng ◽  
Hong Zhang ◽  
Peng Wang
Keyword(s):  
Prediction Method ◽  
Electronic System ◽  
Contact Length ◽  
Trajectory Control ◽  
Analysis Model ◽  
Rotating Shaft ◽  
Element Analysis ◽  
Gap Flow ◽  
Total Leakage ◽  
Gap Height

Lubricant leakage will inevitably occur during the working process of wellbore trajectory control tools. Even including the lubricant compensation system, serious leakage will still cause lacks lubrication of the internal mechanical structure as well as electronic system damaged by external infiltration fluid, especially when it comes to battery sub and other electronic equipment. Seal system leakage prediction method was presented based on the assumption of steady gap flow. It is assumed that there is a constant gap between the lip seal and the rotating shaft, the gap height is determined by oil film thickness, and the length of the gap was determined by the contact analysis using the Mooney–Rivlin constitutive model. The analysis results show that the contact length between the primary seal lip and the rotary shaft is about 0.1 mm under the condition of ensuring the contact between the deputy seal lip and the rotary shaft. The overall lubricant leakage finite element analysis model was established, and the relationship between the internal lubricant pressure of the tool and the total leakage was obtained. The results of analysis indicate that under the internal pressure of 0.03 MPa, the lubricant leakage is approximately 6 mL/h, which was verified by experiments.

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