Articles de revues : « Mechanism vibration »

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Lian, Jijian, Yan Zheng, Chao Liang et Bin Ma. « Analysis for the Vibration Mechanism of the Spillway Guide Wall Considering the Associated-Forced Coupled Vibration ». Applied Sciences 9, n^o 12 (25 juin 2019) : 2572. http://dx.doi.org/10.3390/app9122572.

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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.

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Chen, Ming, Wen Bo Lu et Da Qiang Shu. « Research on Blasting Vibration Safety Assessment Parameters ». Advanced Materials Research 446-449 (janvier 2012) : 582–87. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.582.

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Based on the fluctuation or vibration failure mechanism of structures under blast vibration, the relationship between the amplitude, frequency of blasting vibration and the stress, strain (deformation) of structures is studied. The assessment method of blasting vibration effects is determined. The results indicate that under the fluctuation failure mechanism, the peak stress and strain of structures are proportional to the peak particle vibration velocity. The peak particle velocity (PPV) can be used to evaluate blasting vibration effects, while under vibration failure mechanisms, PPV, the main frequency and the natural frequency of structures must be considered for blasting vibraton effect safety assessment. The peak particle vibration acceleration should not be a separate evaluation parameter for blasting vibraton effects.

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Peng, Liping, Huihui Feng, Zhenqian Wang, Haoyu Wang, Huan Yang et Huan Huang. « Screening Mechanism and Properties of a Cantilevered Vibrating Sieve for Particles Processing ». Applied Sciences 9, n^o 22 (15 novembre 2019) : 4911. http://dx.doi.org/10.3390/app9224911.

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Screening of fine wet particles or near-aperture particles by traditional screen devices is often not quite effective for sieve plugging. Different from traditional rigid regular mesh sieves, a cantilevered vibrating sieve (CVS) with open screen holes, composed of cantilevered sieve rods, was proposed in this paper. The CVS proved to have a higher screen-penetrating probability relative to traditional sieves. By establishing a bending vibration model for the CVS, it can be found that additional vibrations may emerge during the screen body motion, and a smaller difference between the natural circular frequency and the vibration frequency will achieve a larger vibration of cantilevered sieve rod. On this basis, this investigation also analyzed anti-plugging mechanism of the CVS and systematically discussed the influence laws of the geometric parameters and vibration parameters of the sieve on screening efficiency by the discrete element method.

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Герасимов, Dmitriy Gerasimov, Воробьёв, Nikolay Vorobev, Герасимов, Mikhail Gerasimov, Степанищев et Viktor Stepanishchev. « STUDY OF MULTISTAGE VIBRATING MECHANISM WITH THE VIBRATION DIRECTION OF EACH STAGE ». Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, n^o 3 (4 avril 2017) : 88–93. http://dx.doi.org/10.12737/24709.

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In work results analytical studies of multistage a vibratory mechanism. Multistage vibrating mechanism consists of several, arranged in series above each other, vibration levels. Each stage has its own oscillation frequencies and directions action of the driving force. Driving force of each stage of work in one direction. When the addition of oscillations excited by the vibrating by several stages, there is an effect of asymmetric vibrations. When asymmetry oscillations in technical application it is possible control the intensity of and the quality of the work performed. Methodology for the calculation and management of dynamic asymmetry coefficient of the present work.

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Zaccaria, Federico, Edoardo Quarta, Simone Badini et Marco Carricato. « Optimal Design for Vibration Mitigation of a Planar Parallel Mechanism for a Fast Automatic Machine ». Machines 10, n^o 9 (5 septembre 2022) : 770. http://dx.doi.org/10.3390/machines10090770.

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This work studies a planar parallel mechanism installed on a fast-operating automatic machine. In particular, the mechanism design is optimized to mitigate experimentally-observed vibrations. The latter are a frequent issue in mechanisms operating at high speeds, since they may lead to low-quality products and, ultimately, to permanent damage to the goods that are processed. In order to identify the vibration cause, several possible factors are explored, such as resonance phenomena, elastic deformations of the components, and joint deformations under operation loads. Then, two design optimization are performed, which result in a significant improvement in the vibrational behaviour, with oscillations being strongly reduced in comparison to the initial design.

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Tian, Ying, Qing Jian Liu, Lei Zhang, Song Ling Tian et Peng Lin Li. « Research on a Type of Program-Controlled Three-Dimensional Vibration Platform ». Key Engineering Materials 693 (mai 2016) : 1604–10. http://dx.doi.org/10.4028/www.scientific.net/kem.693.1604.

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Conventional mechanical vibration platform vibrates not only in the direction of back and forth but also in the direction of up and down. Vibrations in both directions are achieved by two mechanisms, respectively. Three-dimensional vibration cannot be realized. In this paper, the servo motor, the gear drive mechanism, and the parallel four-bar linkage mechanism are combined with the NC system. And a type of program-controlled three-dimensional vibration platform is designed. The platform can vibrate in three directions, such as the directions of up and down, left and right, back and forth. The parametric adjustment of amplitude and frequency in three directions can be realized. The vibration platform is suitable for high-speed and light-load three-dimensional vibration. Compared with the existing mechanical vibration platform, the designed vibration platform overcomes some deficiencies to realize three-dimensional vibration with variable frequency and amplitude.

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Zhang, Laixi, Chenming Zhao, Feng Qian, Jaspreet Singh Dhupia et Mingliang Wu. « A Variable Parameter Ambient Vibration Control Method Based on Quasi-Zero Stiffness in Robotic Drilling Systems ». Machines 9, n^o 3 (21 mars 2021) : 67. http://dx.doi.org/10.3390/machines9030067.

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Vibrations in the aircraft assembly building will affect the precision of the robotic drilling system. A variable stiffness and damping semiactive vibration control mechanism with quasi-zero stiffness characteristics is developed. The quasi-zero stiffness of the mechanism is realized by the parallel connection of four vertically arranged bearing springs and two symmetrical horizontally arranged negative stiffness elements. Firstly, the quasi-zero stiffness parameters of the mechanism at the static equilibrium position are obtained through analysis. Secondly, the harmonic balance method is used to deal with the differential equations of motion. The effects of every parameter on the displacement transmissibility are analyzed, and the variable parameter control strategies are proposed. Finally, the system responses of the passive and semiactive vibration isolation mechanisms to the segmental variable frequency excitations are compared through virtual prototype experiments. The results show that the frequency range of vibration isolation is widened, and the stability of the vibration control system is effectively improved without resonance through the semiactive vibration control method. It is of innovative significance for ambient vibration control in robotic drilling systems.

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Zhang, Rong Hai, Ning Yuan Zhu et Gai Pin Cai. « Surface Effect Mechanism Analysis for Vibrational Rotary Forging ». Advanced Materials Research 314-316 (août 2011) : 753–58. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.753.

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As a contact of vibrational rotary forging is highly nonlinear, the contact area and boundary between rotary toolhead and workpiece had more accurate calculation, made the contact boundary more tally with the actual situation. For a surface effect is of complexity for vibrational rotary forging, a vibrational rotary forging visco-elasticity plasticity model was built, and the visco-elasticity spatial matrix and the visco-plasticity spatial matrix were derived by the generalized Hooke's law in elasticity theory and the increase theory in mechanics of plasticity, then by the finite element founction of MATLAB for the surface effect analyzed during the vibrational rotary forging deformation, it is shown as blow: the surface effect should be appeared with high frequency vibration or low frequency vibration, but there are some conditions for surface effect produced during plastic process, and then the hypothesis that the friction vector is reversal of deformation load, and it is benefit to deformation process during the part of time in vibration period is validated.

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Pshinko, Oleksandr, Olena Hromova et Dmytro Rudenko. « Study of Rheological Properties of Modified Concrete Mixtures at Vibration ». Materials Science Forum 968 (août 2019) : 96–106. http://dx.doi.org/10.4028/www.scientific.net/msf.968.96.

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Study of rheological properties of concrete mixtures based on modified cement systems in order to determine process parameters. Methodology. To study structural-mechanical properties of modified concrete mixtures of different consistency at their horizontal vibrating displacement an oscillatory viscometer was designed. Results. The optimization of the process of vibration displacement of concrete mixtures with the specification of parameters of vibration impacts taking into account structural-mechanical properties of the mixture is performed. It has been established that the viscosity of the modified cement system of the concrete mixture is a variable quantity, which depends on the parameters of the vibration impacts. Scientific novelty. The mechanism of interaction of the modified concrete mixture with the form and the table vibrator during its vibration compaction is determined. On the basis of this, a model of concrete laying process control is proposed, that allows to predict the ability to form a dense concrete structure. Practical significance. Disclosed physical nature of the process of vibrating displacement of modified concrete mixtures using the principles of physical-chemical mechanics of concrete allows reasonably choose the best options for vibration impacts.

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Yang, Feng, Jun Chuan Niu, Kun Peng Li et Yong Li. « Study on Frequency Tuning of Parallel Mechanism for Reducing Vibration ». Applied Mechanics and Materials 275-277 (janvier 2013) : 905–8. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.905.

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To reduce the multi-dimensional vibration which exist in some vibrating machines or equipments such as running ambulances, a parallel mechanism with 3-translation DOFs was presented and introduced into the ambulance stretcher, then a three-translation vibration reduction platform was developed. The kinematics and dynamics equations of the presented vibration reduction platform were deduced. And then the workspace, tuning principles and dynamics characteristics were studied. The simulations show that the presented parallel mechanism or vibration reduction platform is valid for reducing vibration and the system has different natural frequencies in case that the upper platform of the mechanism works on some specific positions, so it can be used to achieve tunable vibration control.

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Герасимов, М., M. Gerasimov, Н. Воробьев, N. Vorob'ev, В. Иванов et V. Ivanov. « OPTIMIZATION OF PARAMETERS OF TWO-STAGE VIBRATION MECHANISM WITH ASYMMETRIC OSCILLATIONS BY DYNAMIC COEFFICIENT ». Bulletin of Belgorod State Technological University named after. V. G. Shukhov 4, n^o 10 (7 novembre 2019) : 149–53. http://dx.doi.org/10.34031/article_5db3fdb0e8c532.45857437.

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The mechanisms with asymmetric vibrations is the priority direction of development and creation of vibration devices for technological processes in the coming years. Mechanisms with asymmetric vibrations are constructively created on the basis of vibrators with directional vibrations in the form of steps, which differ from each other in the mass of unbalances, the radius of displacement of the center of mass from the axis of rotation and the frequency of rotation of the unbalanced shaft. The simplest device with asymmetric oscillations is a two-stage mechanism. Optimization of parameters of vibrators of each stage can be carried out according to the coefficient of dynamism of the oscillatory system. Rational parameters of the mechanism are consistent with the highest value of the coefficient of dynamism of the system. Currently, there is no method of design calculation for the translation of circular, elliptical and equally directed oscillations into asymmetric ones. The article presents the method of calculation associated with the translation of the parameters of vibration devices with circular, elliptical and equally directed vibrations into asymmetric ones with the highest coefficient of dynamism.

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Lian, Jijian, Hongzhen Wang et Haijun Wang. « Study on Vibration Transmission among Units in Underground Powerhouse of a Hydropower Station ». Energies 11, n^o 11 (2 novembre 2018) : 3015. http://dx.doi.org/10.3390/en11113015.

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Research on the safety of powerhouse in a hydropower station is mostly concentrated on the vibration of machinery structure and concrete structure within a single unit. However, few studies have been focused on the vibration transmission among units. Due to the integrity of the powerhouse and the interaction, it is necessary to study the vibration transmission mechanism of powerhouse structure among units. In this paper, field structural vibration tests are conducted in an underground powerhouse of a hydropower station on Yalong River. Additionally, the simplified mechanical models are established to explain the transmission mechanism theoretically. Moreover, a complementary finite element (FE) model is built to replicate the testing conditions for comprehensive analysis. The field tests results show that: (1) the transmission of lateral-river vibration is greater than those of longitude-river vibration and vertical vibration; (2) the vibration transmission of the vibrations that is caused by the low frequency tail fluctuation is basically equal to that of the vibrations caused by rotation of hydraulic generator. The transmission mechanism is demonstrated by the simplified mechanical models and is verified by the FE results. This study can provide guidance for further research on the vibration of underground powerhouse structure.

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Gallina, Paolo, et Marco Giovagnoni. « Design of a Screw Jack Mechanism to Avoid Self-excited Vibrations ». Journal of Dynamic Systems, Measurement, and Control 124, n^o 3 (23 juillet 2002) : 477–80. http://dx.doi.org/10.1115/1.1484395.

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This paper deals with vibratory phenomena that are encountered in screw jack mechanisms, down-motion especially. One can find many practical instances where such mechanisms are subject to vibratory conditions. Besides producing loud noise, vibrations can easily damage the mechanism. Although the screw jack mechanism has been widely employed, its behavior is still not fully understood. In order to explain the vibration phenomenon, we propose a simple two D.o.F. dynamic model. Using this kind of model, it is shown that vibrations can be avoided by reducing the axial stiffness of the screw.

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Yu, Chang Chun. « Application of Parallel Mechanism in Multi-DIM Vibration Absorbers ». Applied Mechanics and Materials 532 (février 2014) : 297–300. http://dx.doi.org/10.4028/www.scientific.net/amm.532.297.

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It introduces ways and means of designing this kind of vibration absorbers which are presented using parallel mechanisms as the main mechanisms ,it ,which takes the parallel mechanisms with 3-DOF translation as an example, validates the feasibility of the method, and enumerates some of the parallel mechanisms that are fit for multi-DIM vibration absorber. In a word, the multi-DIM vibration absorber system based on parallel mechanism is a new idea and breakthrough in multi-DIM vibration absorption field, which has the characteristic of simple structure, compact mechanism, high accuracy, partially or fully decoupled mechanism easy for control and so on, and provides a new method for the study of Multi-DIM vibration.

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Zou, Ping, Xi Chen, Tao Zhang et Wen Bo Li. « Vibration-Assisted Machining Study Based on 2R-2P Parallel Mechanism ». Advanced Materials Research 1004-1005 (août 2014) : 1103–8. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.1103.

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During the traditional cutting processing, cutting tool and the workpiece contact each other continuously along with the chip removal, this paper puts forward a kind of vibration cutting structure based on the parallel mechanism known as 2R-2P, in which certain elliptical trajectory could be taken, according to the principle of applying separate characteristic between vibrating cutting tool and workpiece to lower cutting force, cutting temperature, so as to improve the machining accuracy. Firstly, illustration in the mechanism of formating the surface morphology in elliptical vibration cutting and the micro trajectory of tip is carried out, secondly, completing the structure design and kinematics analysis, the tip vibration curve has been attained. Finally, through the statics and dynamics analysis, distribution rule of stress and strain is concluded when the structure is subjected to external force changing periodically, as the vibration mode and the harmonious response, verifying the feasibility of the structure and the ability of tip vibrating in ellipse trajectory.

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Teng, Yun Nan, Xiao Peng Li, Qing Hui Zeng et Bang Chun Wen. « Investigation on Nonlinear Dynamics Characteristics of Vibration Friction System Based on Vibration Pile Driver ». Applied Mechanics and Materials 29-32 (août 2010) : 2189–93. http://dx.doi.org/10.4028/www.scientific.net/amm.29-32.2189.

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As a branch of Utilization of vibration, vibration friction is a type of the most valued applicable technology developed during the later part of the 20th century and still in rapid development now. Since the technology is closely associated with industrial and agricultural production, can create huge social and economical benefits for our society and provide excellent service for human beings, it becomes a necessary mechanism in human production and life. The theory of the vibrating machines has been developed and used widely in this field. In this paper, nonlinear dynamic characteristics of vibration friction system based on vibration pile driver were investigated. According to dynamics theory, the motion equation of vibration friction system was established. For further study of vibration friction mechanism and its application on vibrating machines, numerical simulation of vibration pile-soil system was made. Chaos was found in the process of motion. The conclusion of our research is that vibration can decrease rub and wears between vibrating body and materials and it is very important to prolong the working life of machines and their parts.

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Kasajima, Tamon, et Masashi Shiraishi. « Vibration-canceling mechanism and head gimbal assembly with the vibration-canceling mechanism ». Journal of the Acoustical Society of America 120, n^o 3 (2006) : 1168. http://dx.doi.org/10.1121/1.2355960.

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Liu, Jinglei, Guishuai Feng, Jian Zhang, Xiaoyu Zhao, Chuanqing Yu et Min Zhao. « Vibration Isolation Mechanism of Concrete Piles for Rayleigh Waves on Sand Foundations ». Shock and Vibration 2018 (12 décembre 2018) : 1–13. http://dx.doi.org/10.1155/2018/6285491.

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To study the propagation characteristics of Rayleigh waves and the isolation mechanism of a single-row of piles by isolation effects, in this paper we draw a two-dimensional contour map of ζ (normalized acceleration amplitude relative to a measure close at the vibration source) using a vibration test carried out on a sand foundation. In this experiment, we study, in addition to the free field and the single pile cases, settings with two and three piles. The result shows that the vibration caused by the point source in the free field excites Rayleigh waves in a radial direction along the surface of the foundation. Meanwhile, the vibrations of the points along the propagation path on the surface of the foundation are gradually weakened. There is a steady transition when the ζ drops to 0.6 and a placid decline when ζ decreases to less than 0.25. The vibration-shielded region, the strengthened region, and the strengthened strips will appear on the surface of the foundation. The vibration-shielded region is located behind the piles, and the region presents a trumpet-shaped area that takes the pile as the vertex. Increasing the quantity of piles contributes to increasing the vibration isolation effect, not only that involving the degree of isolation but also for the area of the shielded area. The vibration-strengthened regions include the diffraction regions at the pile corners on both sides of the single-row of piles and the scattering region at the gaps of the piles. In addition, the composite regions are located among the vibration source and the scattering and diffraction-strengthened regions. Increasing the number of piles has little influence on the scattering and diffraction-strengthened regions but can significantly enhance the vibrations of the composite regions. In general, the vibration-strengthened strips are connected with the scattering-strengthened regions. However, in the test of a single pile, the pile is connected to the diffraction-strengthened regions near its two anterior angles.

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Deng, Shan, Ding Ding Zhao et Ping Cai. « Study on the Calibration of Dynamic Balancing Machine for Separating System Interference Vibration ». Key Engineering Materials 613 (mai 2014) : 408–14. http://dx.doi.org/10.4028/www.scientific.net/kem.613.408.

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The minimum achievable residual unbalance ratio emaris the index for evaluating the balancing capability of dynamic balancing machine. When the emaris expected to achieve to 0.1um grade or higher, to tap potential solely from the design of the signal conditioning circuits or the digital signal processing algorithm could not settle problems completely, equal importance should be paid on eliminating the influence of machine intrinsic interference vibration. Unfortunately, compared with much effort on the research and implementation of circuits and algorithm for unbalance signal extraction, little attention has been paid on the latter. This paper puts forward an interference vibration separation approach based on multi-point test-mass circulation calibration, to the purpose of improving the overall performance of balancing machine.The measurement system of a dynamic balancing machine composed of vibration mechanism, vibration pick-up sensor, signal conditioning circuits and the digital signal processing module, wherein the vibration mechanism locates on the front end and is of great importance. In the current design of dynamic balancing machine, there is a hypothesis that the vibration mechanism vibrates in the manner of simple harmonic oscillation forced by the unbalance of the under test rotate work piece and the amplitude and initial phase of that vibration are only related to the magnitude and angle position of the unbalance. In a practical balancing machine, however, the unbalance of driving devices, the coaxial error of the coupling or the vibration of the driving belt will incur additional vibrations to the vibration mechanism. Being of the same frequency or nearby frequency with the unbalance vibration, those interference vibrations are difficulty to remove by the signal conditioning circuits or the digital signal processing approach.Based on the invariability of the machine intrinsic interference vibration, this paper developed a circumference multi-point measurement and compound calibration method. The principle of the method will be introduced and analyzed in detail in the paper. Based on the vector operation and least square fitting to the unbalance vibration response with the obtained compound vibrations, the interference vibration can be separated to a satisfied extent. Experiments investigation is carried out on a hard bearing dynamic balancing machine, and the experiment results demonstrate the feasibility of the said method.

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Stejskal, Tomáš, Juraj Kováč et Štefan Valenčík. « Mechanism of Randomness in Vibration Signals of Machinery ». Applied Mechanics and Materials 282 (janvier 2013) : 257–62. http://dx.doi.org/10.4028/www.scientific.net/amm.282.257.

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The paper deals with a special analysis of the vibration signal, which may reveal the chaotic behavior of the machine. The most likely effect of randomness is an exponential distribution. In case of the time interval divisions between peaks signal from vibrating machinery process has not a unique character of exponential distribution.

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Ren, Yan, Jian Ruan et Ji Yan Yi. « Separate Control Characteristics of Electro-Hydraulic Vibrator Using a Parallel Mechanism ». Advanced Materials Research 199-200 (février 2011) : 953–57. http://dx.doi.org/10.4028/www.scientific.net/amr.199-200.953.

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A scheme of the separate control technique of electro-hydraulic vibrator is proposed, in which symmetrical hydraulic cylinder is controlled by a parallel mechanism of a two-dimensional valve (named as 2D valve) and a parallel servo valve. The working frequency and vibration amplitude of the electro-hydraulic vibrator are dominated by the rotary speed and the sliding displacement of the spool of the 2D valve respectively, and the vibration central piston is controlled by the sliding displacement of the spool of the parallel servo valve. This paper analyzes the relationship between vibration characteristic values and control parameters using the analytic method based on the hydrodynamic control theory. The experimental system is built to verify that the theoretical analysis is consistent with measured results.

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Khajehzadeh, Mohsen, Omid Boostanipour, Soheil Amiri et Mohammad Reza Razfar. « The influence of ultrasonic elliptical vibration amplitude on cutting tool flank wear ». Proceedings of the Institution of Mechanical Engineers, Part B : Journal of Engineering Manufacture 234, n^o 12 (16 juin 2020) : 1499–512. http://dx.doi.org/10.1177/0954405420929782.

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In this article, the effect of vibration amplitude during ultrasonic elliptical vibration–assisted turning on cutting tool flank wear ( VBmax) and tool diffusion wear mechanism has been experimentally studied in machining of AISI 4140 hardened steel. To achieve this goal, an ultrasonic elliptical vibration–assisted turning setup was designed and manufactured. This device was then used in both ultrasonic-assisted tuning and ultrasonic elliptical vibration–assisted turning tests (i.e. one-dimensional and two-dimensional ultrasonic-assisted machining). According to the achieved results, ultrasonic elliptical vibration–assisted turning is more effective than ultrasonic-assisted tuning in reducing tool flank wear; at an amplitude of 13 μm, work velocity of 180 mm/s and feed of 0.09 mm/rev, VBmax were decreased 30.3% and 54.3%, respectively, in case of ultrasonic-assisted tuning and ultrasonic elliptical vibration–assisted turning. It was also observed that increasing the amplitude of ultrasonic vibrations reduces VBmax; at work velocity of 180 mm/s and feed of 0.09 mm/rev, the reduction of VBmax in ultrasonic elliptical vibration–assisted turning with amplitudes of 5 and 13 μm is, respectively, 39.3% and 54.3%, compared with that of conventional machining. The results also show that the application of ultrasonic vibrations weakens the cutting tool diffusion wear mechanism. This attenuation is much higher for ultrasonic elliptical vibration–assisted turning in comparison to ultrasonic-assisted tuning. Besides, the amount of attenuation in cutting tool diffusion wear mechanism decreases with increasing vibration amplitude.

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Rajabpour, Leila, Hazlina Selamat, Alireza Barzegar et 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 octobre 2021) : e756. http://dx.doi.org/10.7717/peerj-cs.756.

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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.

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Beikmann, R. S., N. C. Perkins et A. G. Ulsoy. « Nonlinear Coupled Vibration Response of Serpentine Belt Drive Systems ». Journal of Vibration and Acoustics 118, n^o 4 (1 octobre 1996) : 567–74. http://dx.doi.org/10.1115/1.2888336.

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This theoretical and experimental study identifies a key nonlinear mechanism that promotes strongly coupled dynamics of serpentine belt drive systems. Attention is focused on a prototypical three-pulley system that contains the essential features of automotive serpentine drives having automatic (spring-loaded) tensioners. A theoretical model is presented that describes pulley and tensioner arm rotations, and longitudinal and transverse belt vibration response. A recent investigation demonstrates that infinitesimal belt stretching creates a linear mechanism that couples transverse belt vibration to tensioner arm rotation. Here, it is further demonstrated that finite belt stretching creates a nonlinear mechanism that may lead to strong coupling between pulley/tensioner arm rotation and transverse belt vibration, in the presence of an internal resonance. Theoretical and experimental results confirm the existence of this nonlinear coupling mechanism. In particular, it is shown that very large transverse belt vibrations can result from small resonant torque pulses applied to the crankshaft or accessory pulleys. These large amplitude transverse vibrations are particularly sensitive to seemingly small changes in the rotational mode characteristics.

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Liu, Ying Xiang, Jun Kao Liu, Wei Shan Chen et Sheng Jun Shi. « Actuating Mechanism and Analysis of a Square-Type Rotary Ultrasonic Stator Using Longitudinal Vibration Transducers ». Applied Mechanics and Materials 16-19 (octobre 2009) : 323–27. http://dx.doi.org/10.4028/www.scientific.net/amm.16-19.323.

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A square-type rotary ultrasonic stator using longitudinal vibration transducers is proposed. The proposed stator contains four longitudinal vibration transducers, which are located in square-type. Every longitudinal transducer includes two exponential shape horns located on each end. And the horns of adjacent transducers intersected at tip ends where located the driving feet. The longitudinal vibrations of transducers are excited by the longitudinal vibrations of PZT ceramics. Longitudinal vibrations of adjacent transducers are superimposed in the driving foot and generated elliptical trajectory. The actuating mechanism is analyzed, and the motion trajectories of driving feet are deduced. The stator is designed and analyzed by using FEM method. The vibration characteristic of stator is gained by transient analysis. Results indicate that the motion trajectories of the four driving feet have good consistency, and the proposed motor has potential good output characteristics. The results of this paper verify the theoretical feasibility and provide instructions for the development of proposed stator.

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Peicheng, Shi, Shi Peilei, Nie Gaofa, Tang Ye et Pan Daoyuan. « Research on Displacement Transfer Characteristics of a New Vibration-Isolating Platform Based on Parallel Mechanism ». Mathematical Problems in Engineering 2017 (2017) : 1–8. http://dx.doi.org/10.1155/2017/8743868.

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Based on the parallel mechanism theory, a new vibration-isolating platform is designed and its kinetic equation is deduced. Taylor expansion is used to approximately replace the elastic restoring force expression of vibration-isolating platform, and the error analysis is carried out. The dynamic-displacement equation of the vibration-isolating platform is studied by using the Duffing equation with only the nonlinear term. The dynamic characteristics of the vibration-isolating platform are studied, including amplitude-frequency response, jumping-up and jumping-down frequency, and displacement transfer rate under base excitation. The results show that the lower the excitation amplitude, the lower the initial vibration isolation frequency of the system. The influence of the platform damping ratio ζ on displacement transfer rate is directly related to the jumping-down frequency Ωd and the external excitation frequency. The vibration-isolating platform is ideally suited for high-frequency and small-amplitude vibrations.

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Sun, Yan Ping, et De Chen Zhang. « Research on the Vibration of Rolling Mill ». Advanced Engineering Forum 2-3 (décembre 2011) : 843–47. http://dx.doi.org/10.4028/www.scientific.net/aef.2-3.843.

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In this paper a horizontal vibration problem in strip rolling was studied; dynamic model was established; the mechanism of self-excited vibration was analyzed. The main reason of surface quality of strip is self-excited vibration. A vertical natural frequency and vibration mode of the rolling mill are obtained by finite element method. It lays the theoretic foundation for future researches on rolling mill vibraton.

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Li, Xiao Peng, Chun Shi Liu, Jie Huang et Bang Chun Wen. « Theoretical Research and Experiment of Vibration Friction on Vibratory Compaction Experiment System ». Advanced Materials Research 118-120 (juin 2010) : 414–18. http://dx.doi.org/10.4028/www.scientific.net/amr.118-120.414.

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Friction under vibration condition presents extremely different complex characteristics from that of the conventional state. Practice shows that machine power rises obviously with the significant decrease of the fiction. However, occurrence mechanism of the vibration is not fully studied or revealed; therefore, how to further develop the benefits of vibration, there is no concrete and clear measures yet. From this actual situation, this work want to reveal the characters of nonlinear dynamic of the vibration friction, analyze the relationship between vibration and friction, discuss the impact of vibration’s parameters on the friction mechanism, Theoretical study and experimental verification were conducted to improve the work efficiency of the related equipments with the benefits of the vibration friction.

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Chen, Wei Shan, Ying Xiang Liu, Jun Kao Liu et Sheng Jun Shi. « Actuating Mechanism and Design of a Double Driving Feet Linear Ultrasonic Motor Using Longitudinal Vibration Transducer ». Key Engineering Materials 434-435 (mars 2010) : 775–78. http://dx.doi.org/10.4028/www.scientific.net/kem.434-435.775.

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A double driving feet linear ultrasonic motor using longitudinal vibration transducer is proposed in this paper. The stator of proposed motor contains a horizontal transducer and two vertical transducers. The horizontal transducer includes two exponential shape horns located at the leading ends, and each vertical transducer contains one exponential shape horn. The horns intersected at the tip ends where located the driving feet. The horizontal and vertical vibrations of driving feet are generated by the longitudinal vibrations of horizontal and vertical transducers, respectively. Longitudinal vibrations are superimposed in the stator and generated elliptical motions at the driving feet. The two vibration modals of stator are gained with FEM, and the resonant frequencies of two vibration modals are degenerated by adjusting the structural parameters. Transient analysis of piezoelectric coupling states the good and strong elliptical motions of driving feet, and verifies the theoretical feasibility of proposed motor.

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Meng, Dejian, Lijun Zhang, Xiaotian Xu, Yousef Sardahi et Gang S. Chen. « Sensing and Quantifying a New Mechanism for Vehicle Brake Creep Groan ». Shock and Vibration 2019 (26 février 2019) : 1–10. http://dx.doi.org/10.1155/2019/1843205.

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This paper investigates the creep groan of a vehicle’s brake experimentally, analytically, and numerically. Experimentally, the effects of acceleration on caliper and strut, noise, brake pressure, and tension are measured. The results show that the measured signals and their relevant spectra broadly capture the complex vibrations of creep groan. This includes the simple stick-slip, severe stick-slip vibrations/resonances, multiple harmonics, half-order harmonics; stick-slip-induced impulsive vibrations, steady/unstable vibrations, and their transitions. Analytically, a new mathematical model is presented to capture the unique features of half-order harmonics and the connections to fundamental stick-slip/resonant frequency and multiple harmonics. The analytical solution and the experimental results show that the vibro-impact of the brake pad-disc system can be triggered by severe stick-slip vibrations and is associated with instable, impulsive stick-slip vibration with wideband. The induced stick-slip vibro-impact can evolve into a steady and strong state with half-order, stick-slip fundamental, and multiple-order components. This new mechanism is different from all previously proposed mechanisms of creep groan in that we also view some type of creep groan as a stick-slip vibration-induced vibro-impact phenomenon in addition to conventional stick-slip phenomena. The new mechanism comprehensively explains the complex experimental phenomena reported in the literature. Numerically, the salient features of phase diagrams of instable stick-slip and vibro-impact are examined by using a seven-degree-of-freedom brake system model, which shows that the phase diagrams of the dynamics of creep groan with and without vibro-impact are substantially different. The phase diagram of the dynamics with vibro-impact is closer to the experimental results. In contrast to existing mechanisms, the proposed new mechanism encompasses the instable stick-slip nature of creep groan and elaborates the inherent connections and transition of the spectrogram. The new knowledge can be used to attain critical improvements to brake noise and vibration analysis and design. By applying the proposed new model in addition to existing models, all experimental phenomena in creep groan are elaborated and quantified.

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Tong, Fu Qiang, Yong Zhang, Fei Hu Zhang, Jing Yu Lu, Li Zhi Gu et Ya Chun Chen. « Study on Mechanism of Vibration Cutting ». Key Engineering Materials 375-376 (mars 2008) : 42–46. http://dx.doi.org/10.4028/www.scientific.net/kem.375-376.42.

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Research on the mechanism of vibration cutting was carried out by analyzing the process of vibration cutting and comparing the model of vibration cutting and conventional cutting. Proper speed coefficient k can help to reduce the average cutting force while increase the cutting efficiency according to the velocity and acceleration equation of vibration tool. Dynamic model of conventional cutting and vibration cutting were built respectively. Compared with conventional cutting, it’s easier for vibration cutting to realize productivity gain, high machining accuracy and good surface finish.

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Teng, Yun Nan, Jia Li, Li Yang Xie et Bang Chun Wen. « Simulation on Vibration Friction Mechanism of Vibration Pile System ». Applied Mechanics and Materials 365-366 (août 2013) : 416–19. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.416.

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Vibratory pile drivers are widely used in mechanical industry field. In this paper, the nonlinear dynamic model of vibration friction pile-soil system considering the soil friction force is proposed. By numerical simulation, the dynamics characteristics of vibration friction for pile-soil system were obtained. The results showed that with the increasing of excitation amplitude and frequency, the displacement of the pile and frame are both increased.

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Teng, Yun Nan, Li Yang Xie et Bang Chun Wen. « Study on Vibration Friction Mechanism of Vibration Compaction System ». Advanced Materials Research 706-708 (juin 2013) : 1594–97. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.1594.

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The mechanism model of vibration compaction system was built. The vibration friction mechanism of vibratory compaction system was studied based on granular dynamics theory. The results show that the void ratio does a great impact on strength and compaction.

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Gu, Zhanfei, Hailong Wei, Zhikui Liu et Mingfei Zhang. « Dynamic Response Mechanism of Silt Ground under Vibration Load ». Sustainability 14, n^o 16 (19 août 2022) : 10335. http://dx.doi.org/10.3390/su141610335.

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The frequent vibration loads during the operation of trains can cause vibration deformation of the tunnel structure and surrounding weak strata, thereby endangering the safe operation of trains. The purpose of this paper is to study the dynamic response of surrounding soil layers caused by train vibrations through the finite difference method with FLAC3D. Based on existing research, we studied the artificially deterministic exciting force function. Then, we simulated the tunnel working conditions of a train with a 3D model, and applied the artificially deterministic exciting force function to the tunnel model. To study the vibration caused by trains in silty soil, we divided the trains into two cases, one-way and two-way. We compared the displacement–time curves of one-way and two-way trains. When the horizontal distance between the monitoring point and the vibration source increases, the peak value of the displacement–time curve decreases. As the speed of the train increases, the peak value of the displacement–time curve increases. The vertical displacement of the ground under the dynamic load of the two-way train is greater than that of the one-way train. In the acceleration–time curve, there is a lag in the ground acceleration response. The faster the speed of the subway train, the greater the peak value of the acceleration–time curve. This study can provide a guide for the evaluation and prevention of ground vibration subsidence and uneven subsidence of strata in the silt area of the Yellow River Region.

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Li, Kuinian, et Mitchell Gohnert. « Lever mechanism for vibration isolation ». Applied Technologies and Innovations 1, n^o 1 (9 avril 2010) : 21–28. http://dx.doi.org/10.15208/ati.2010.3.

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Kuo, C. W., S. M. Yang, J. H. Chen, G. H. Lai et W. Wu. « Study of vibration welding mechanism ». Science and Technology of Welding and Joining 13, n^o 4 (mai 2008) : 357–62. http://dx.doi.org/10.1179/174329308x299959.

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Chkhaidze, Тengiz, Gabriel Merabishvili et Alexander Metreveli. « The Impact of Vibration Operational Reliability of Turning Mechanism of Gantry and Tower Cranes ». Works of Georgian Technical University, n^o 3(521) (29 septembre 2021) : 92–101. http://dx.doi.org/10.36073/1512-0996-2021-3-92-101.

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Impacts of vibration on operational reliability of turning mechanisms of gantry and rower cranes are considered. Besides that, the structural features of kinematic chain of drive, including gear transmission with internal large module teeth, roller bearing without retaining ring, excitement of torsional, bending low-frequency vibrations at operation in nominal mode of cargo lifting that causes the origination of of increasing friction moment and stop of turning mechanism are researched in this article. Moreover, the technological and structural solutions aimed on decreasing of excited vibrations are proposed, and the supporting-rotating rolling bearings without retaining ring with improved technical-economic indicators are considered.

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Chen, Jiayao, Ying Wang, Dongtai Liang, Wenhao Xu et Yang Chen. « Design of a Buffered Longitudinal Vibratory Picking Mechanism for Berry Shrub Fruits ». Transactions of the ASABE 64, n^o 4 (2021) : 1165–71. http://dx.doi.org/10.13031/trans.14119.

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HighlightsA spring buffering system was added to a longitudinal vibration picking mechanism for berry shrub fruits.Vibration models of the picking part and side branch were established to obtain the vibration relationship.Blueberry picking experiments were conducted to verify the performance of the picking mechanism.Abstract. Current berry shrub picking mechanisms are generally rigid structures, which can easily cause the mechanism to jam and produce rigid impacts, damaging the berry shrub branches. In view of this situation, a longitudinal vibratory picking mechanism for berry shrub fruits is proposed in this study with a spring system added to provide a buffering effect. Vibration models were established for the picking part and for the berry shrub side branch, and analysis was performed to obtain the vibration relationships. Using blueberry as an example, suitable parameters were determined through calculation and then used in blueberry picking experiments with a prototype of the picking mechanism. The experiments verified that the vibration frequency calculated with the vibration relationships can meet the requirements for picking, and the performance of the longitudinal vibratory picking mechanism for berry shrub fruits was verified. Keywords: Berry shrub picking, Buffer, Longitudinal vibration, Vibration analysis.

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Yan, Bo, Ning Yu et Chuanyu Wu. « A state-of-the-art review on low-frequency nonlinear vibration isolation with electromagnetic mechanisms ». Applied Mathematics and Mechanics 43, n^o 7 (juillet 2022) : 1045–62. http://dx.doi.org/10.1007/s10483-022-2868-5.

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AbstractVibration isolation is one of the most efficient approaches to protecting host structures from harmful vibrations, especially in aerospace, mechanical, and architectural engineering, etc. Traditional linear vibration isolation is hard to meet the requirements of the loading capacity and isolation band simultaneously, which limits further engineering application, especially in the low-frequency range. In recent twenty years, the nonlinear vibration isolation technology has been widely investigated to broaden the vibration isolation band by exploiting beneficial nonlinearities. One of the most widely studied objects is the “three-spring” configured quasi-zero-stiffness (QZS) vibration isolator, which can realize the negative stiffness and high-static-low-dynamic stiffness (HSLDS) characteristics. The nonlinear vibration isolation with QZS can overcome the drawbacks of the linear one to achieve a better broadband vibration isolation performance. Due to the characteristics of fast response, strong stroke, nonlinearities, easy control, and low-cost, the nonlinear vibration with electromagnetic mechanisms has attracted attention. In this review, we focus on the basic theory, design methodology, nonlinear damping mechanism, and active control of electromagnetic QZS vibration isolators. Furthermore, we provide perspectives for further studies with electromagnetic devices to realize high-efficiency vibration isolation.

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Guerra-Bravo, Esteban, Han-Joo Lee, Arturo Baltazar et Kenneth J. Loh. « Vibration Analysis of a Piezoelectric Ultrasonic Atomizer to Control Atomization Rate ». Applied Sciences 11, n^o 18 (9 septembre 2021) : 8350. http://dx.doi.org/10.3390/app11188350.

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In this work, a mechanical vibrational analysis of an ultrasonic atomizer is carried out to control its atomization mass transfer rate. An ultrasonic atomizer is a device constructed with a piezoelectric ring coupled to a metallic circular thin plate with micro-apertures. The mechanism of mass transfer by atomization is a complex phenomenon to model because of the coupling effect between the fluid transfer and dynamic mechanics controlled by a piezoelectric vibrating ring element. Here, the effect of the micro-apertures shape of the meshed thin plate coupled to a piezoelectric ring during vibration, as well as the resonance frequency modes, are numerically studied using a finite element analysis and compared with theoretical and experimental results. Good correlations between the predicted and experimental results of the resonant frequencies and atomization rates were found.

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Sun, Jian, et Gui Yun Xu. « Dynamics Analysis of Double-Tamper Mechanism for Asphalt Paver ». Applied Mechanics and Materials 130-134 (octobre 2011) : 566–70. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.566.

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Owing to the tamping mechanism of paving machines, the shocks towards flatiron-box are produced by compound motion of tamping beam. This significantly influences the road paving quality. In this paper, the dynamics model of double-tamper mechanism is established and the vibration process is simulated by the numerical analysis software—Matlab. Through the analysis of double-tamper mechanism, we can get the impact regularity of the vibrating beam inertia force and moment of inertia as a result of the vibration frequency and amplitude. It provides a reference for the design of double-tamper mechanism for asphalt paver and the adjustment of construction parameters.

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Sun, Tian Xing, Ming Fang Chen, Qi Sun et Yong Xia Zhang. « Research of Elliptic Ultrasonic Vibration Mechanism ». Applied Mechanics and Materials 789-790 (septembre 2015) : 156–59. http://dx.doi.org/10.4028/www.scientific.net/amm.789-790.156.

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Elliptical vibration cutting is a new processing technology of work piece surface texture generation, the technique based on conventional cutting machine main movement and feed motion of the tool, by changing the structure so that the tip motion to generate ellipse trajectory. This paper designed incentive range vibration frequency as 20~40 KHz, can generate elliptical vibration trajectory in the small space of X/Z axis 16um. Tests prove that, the ultrasonic elliptic vibration cutting mechanism improves the specimen surface texture, smooth discharging of chipping, greatly improving the surface finishes of the work piece.

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Zhu, Wei, De Jun Kong et Ai Ping Hu. « Modal Analysis and Design of Six Dimensional Vibration Damping Device Based on Hexapod Platform ». Applied Mechanics and Materials 33 (octobre 2010) : 128–31. http://dx.doi.org/10.4028/www.scientific.net/amm.33.128.

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A six dimensional vibration damping device is introduced which is composed of Hexapod parallel mechanism and six controllable damp units fixed on driving pairs. Firstly, the structure of the system is designed according to theory of the Hexapod mechanism. Then, Jacobian matrix and dynamics model are discussed successively. Lastly, a six dimensional vibration model is found by using ADAMS software. Through theory and simulation analysis, it has been approved that the system can be used to control six dimensional vibrations.

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Gerasimov, M., N. Vorobiov, M. Romanovich et E. Amini. « The dynamic factor determination of the vibration mechanism with asymmetric vibrations ». IOP Conference Series : Materials Science and Engineering 698 (18 décembre 2019) : 066039. http://dx.doi.org/10.1088/1757-899x/698/6/066039.

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Sun, Shuguang, Jingrui Cui et Taihang Du. « Research on the Influence of Vibrations on the Dynamic Characteristics of AC Contactors Based on Energy Analysis ». Energies 13, n^o 3 (23 janvier 2020) : 559. http://dx.doi.org/10.3390/en13030559.

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Aimed at the influence of the vibration environment on the performance degradation of AC contactors, the purpose of this study is to investigate the failure mechanism of AC contactors under vibration conditions. During the closing process of AC contactors, the impact energy of the iron core may change due to the vibration stress, which may have an uncertain effect on the parameters of the dynamic response characteristics of the contact, and affect the working performance and service life of AC contactors. In this paper, a double-E AC contactor is selected as the research object. Based on the calculation of the transient magnetic field of the electromagnetic mechanism, an energy distribution model of the AC contactor is established. Based on this, considering the influence of vibrations and the input electrical energy under different closing phase angles, the energy model of the iron core collision under simple harmonic oscillation is investigated. The steady-state vibration energy at different frequencies and accelerations is calculated, and its influence on the dynamic response parameters of the AC contactor is analyzed. Finally, the simulation model is verified by experimental data. The results show that the energy analysis model can effectively reflect and explain the uncertainty of the dynamic characteristics of AC contactors under vibrations, from the perspective of the mechanism.

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Yang, Xiao Lan, Ji Feng Liu et Jing Chao Zou. « Numerical Simulation and Mechanism Study of Two Level Partial Blocks Vibration Motor ». Advanced Materials Research 396-398 (novembre 2011) : 2463–66. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.2463.

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In order to finish some special operations, the chaotic vibrating motor with two-level partial blocks is constructed. Mechanism principles are designed and dynamics of mechanical model is analyzed by using Lagrange method. Based on the initial sensitivity, non-repetition and complexity of phase-trajectory, many characteristics of chaotic vibration are verified in the vibrating system. It is found the vibrating system with wide power spectrum can achieve some special properties like transient high-intensity, super high-intensity and large vibrating amplitude. It is important to overcome some work barriers and solve some technological bottlenecks of vibrating machinery.

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Hu, Wei, Jianming Wu, Qinghua Zhu, Jie Shen, Xunjiang Zheng, Shaoyong Sun, Xiaonan Mao, Honglei Cao et Yucong Tang. « Active Vibration Control of a Large Flexible Appendage Using a Novel Joint Mechanism ». Shock and Vibration 2022 (23 juin 2022) : 1–15. http://dx.doi.org/10.1155/2022/8361367.

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With the evolution of space exploration, large flexible appendages have been developed in space structures. External perturbation or attitude maneuvering stimulates the vibration (low frequencies) of the aforementioned structures. In this research, a novel joint mechanism was developed in conjunction with active control to inhibit the low-frequency vibration of a large flexible appendage. A compact active joint, based on the idea of electromagnetic direct drive, was designed. The dynamic equations for the large flexible appendage system and the active joint were derived using the Lagrange function with the assumed-modes approach. Single- and multi-frequency excitations were simulated by two noncontact strategies for periodic vibration stimulation along the direction of rotation. The research results revealed that the interference signal had a primary frequency bandwidth of 0.07–0.63 Hz, and the vibration attenuation was prominent between 5.95 and 32.41 dB within the valid bandwidth. Effective inhibition of both the larger and the smaller amplitude vibrations at frequencies lower than 1 Hz could be realized using the proposed active joint without attachment of intelligent materials onto the flexible appendage surface.

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Tsurkan, Oleh, Yurii Polievoda et Dmytro Prysyazhniuk. « INVESTIGATION OF MATHEMATICAL MODEL OF A VIBRATING MIXER WITH A FREEZERY PENDULUM MECHANISM ». ENGINEERING, ENERGY, TRANSPORT AIC, n^o 3(114) (28 septembre 2021) : 124–35. http://dx.doi.org/10.37128/2520-6168-2021-3-14.

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An extensive review of vibrating mixers, identified their advantages and disadvantages. The application of the action of low-frequency oscillations on the process of mixing bulk inhomogeneous products is substantiated. All considered schemes of vibrating mixers, as well as designs in which mixing devices are driven by vibration-pulse transducers (in which the energy of the main or master system is used to create the technological motion of the driven system) can be attributed to energy-saving technological equipment. The article describes the design, the principle of operation of the developed vibrating mixer with a double pendulum freewheel mechanism for driving the agitator blades in rotational motion. The calculation scheme and laws of motion of this system in the form of Lagrange equations of the second kind (mathematical model) are presented. Using the obtained 2nd order multiple regression equations, recommendations were determined regarding the main parameters of the operating mode of the studied vibration mixing process. Analyzing the results of vibration mixing of bulk inhomogeneous raw materials, we can say that the most influential factors in determining the natural oscillation frequency of the system pendulum, which is one of the main objectives of our study is spring stiffness, spring attachment distance from axis of rotation, rotation angles, pendulum weight, length and the moment of inertia. The paper proves that among various forms of mechanical action on dispersed systems in technological processes vibration action occupies an important place as one of the most effective means to create the necessary dynamic state of dispersed systems.

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Mou, Shann Chyi, Li Hui Yang et Ying Hao Chen. « Design and Analysis of a Ultrasonic Sliding Platform ». Applied Mechanics and Materials 232 (novembre 2012) : 930–34. http://dx.doi.org/10.4028/www.scientific.net/amm.232.930.

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This article is meant to perform the simulation behavior of fluctuation and vibration for the ANSYS software against piezoelectric structure. From the relevant analysis, it can be aimed to devise the single-axis ultrasonic sliding platform inclusive of propeller system and sliding mechanism. Within both systems of propeller system and sliding mechanism, they are adopted with the piezoelectric buzzer as the material for driving components. The propeller actuator (propeller system), on the Ni-alloy plate of buzzer, will be divided to the non-axisymmetric structure at the respective angles of 90º, 120º and 150º with the resultantly produced radial vibration to move the platform. Also, the sliding vibrator (sliding mechanism) will be evenly divided into 3 parts of axisymmetric structure at the angle of 120º with its longitudinal vibration to reduce the friction caused by platform movement. In the designing process, it is adopted with the finite element analysis software - ANSYS to perform analysis and simulation for the vibration patterns of actuator and vibrator. By measuring the friction coefficient of sliding platform, it is well verified that the introduction of sliding mechanism will certainly reduce the friction caused by platform movement. The static friction coefficient will be reduced from 0.37 to 0.2 to result in considerably increasing displacement speed of platform.

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Wang, Jiyao, Xufeng Wang, Xuyang Chen, Liang Chen, Zhanbiao Yang, Zechao Chang, Lei Zhang et Zhijun Niu. « Experimental Study on Failure Law and Mechanism of Red Sandstone under Ultrasonic Vibration Excitation ». Geofluids 2022 (17 février 2022) : 1–13. http://dx.doi.org/10.1155/2022/3078599.

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Rock breakage is inevitable for creating openings in underground engineering operations. Ultrasonic vibration has been attracting extensive attention for such a practice considering its outstanding performance in rock breakage. In order to understand the fundamental failure mechanism of rocks subjected to ultrasonic vibrations, based on P-wave monitoring and the direct current electric method, we captured the evolution of the failure process of the red sandstone. In addition, we fundamentally analyse the failure mechanisms of the red sandstone using numerical simulation and microscopy scans. It was found that extensive fractures were initiated due to the ultrasonic vibration and the fractures propagated downwards forming a conical shape. The apparent resistivity became as high as 320000 Ω being 16 times the initial resistivity. The fracture propagated downwards as deep as 41 mm. The maximum damage parameter on the testing sample could be as high as 0.68, and it completely failed after 140 s of ultrasonic vibration duration. As a result of numerical simulation, it was found that the microfractures and pores in the testing sample were activated due to the stress wave resulting from the ultrasonic vibration leading to the fracture propagation and eventually complete failure. Through comparing the performance of uniaxial compressive loading and ultrasonic vibration techniques in rock damage, it was concluded the latter has a much higher capacity and competence in rock breakage.

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