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The Mindlin plate equations have been the primary choice for the analysis of high frequency vibrations of AT- and SC-cut quartz crystal plates in the design of resonators for predictions of vibration frequency, mode couplings, and bias effects. However, the plate equations have to be modified to yield exact solutions in certain frequency range and correction factors are chosen in a systematic manner...
In the design of quartz crystal resonators, it is always required to have complete information about vibration couplings in the vicinity of thickness-shear mode for the suppression of spurious modes which always cause performance degradation as one of the most serious challenges in product development. The couplings of vibration modes are caused by the finite size of plates and material constants,...
In this work, a novel Green's function technique is used to solve for plate deflection of a piezoelectric micromachined ultrasonic transducer (pMUT) under the influence of residual stress. The pMUT is modelled as a clamped, circular diaphragm consisting of a stack of structural and piezoelectric material actuated by an arbitrary number of circular electrodes. From classic plate theory, the equation...
By using a pair of bimorph transducers, we have already miniaturized a traveling-wave-based ultrasonic linear motor and achieved a diameter of < 10 mm, but its motor performances were not sufficient for practical applications. In this study, in order to improve its performances, the motor structure is optimized with the two methods: by reducing the thickness of the transmission bar, and by...
This paper focuses on the development of a multivariable predictive controller for vibration suppression of a flexible manipulator using piezoelectric actuator. To the best of the authors knowledge, the predictive controller for active vibration suppression has been rarely studied, so making it a prime area research to explore. A two-step procedure performed to develop the detailed model of the whole...
The method for the mesh stiffness calculation of gear pair through Loaded Tooth Contact Analysis is presented in this paper. The mesh stiffness and load distribution of a helical gear pair are calculated. On that basis, the effect of two kinds of axial angle errors on mesh stiffness is compared and the effect of axial modification on mesh stiffness is analysed. The research demonstrates that the axial...
The rotary cranes (tower crane) main purpose in finding a proper control strategy to transport the loads from one location to another. The controlling approach should consider two main factors which are minimizing the moving time of the payload from the primary pick up point to the destination point and second, the oscillation of the payload must be reduced to prevent hazards for people and equipment...
Considering the effect caused by the spindle angle and friction force of roll gap on the main drive system of rolling mill, the nonlinear torsional vibration dynamical equation of rolling mill's drive system is established, which contains parametrical stiffness and nonlinear friction damping. The amplitude-frequency characteristic equation and bifurcation response equation are obtained by solving...
In consideration of the bearing stiffness, the contact deformation between the ball screw and the worktable, and the contact deformation between the worktable and the guide, lateral, longitudinal and torsional vibration of the preload screw and vibration of the worktable are studied. Dynamic model of the ball screw drive system of machines is established using Lagrange equation. The model is analyzed...
This paper analyzes a vibration problem occurs in multi-way valve throttle load experiment. The dynamic process of the vibration in throttle valve is first analyzed to find out the key parameters relating to the vibration. Then an AMESim model of the hydraulic system with the vibrating throttle valve has been built. Detailed research on how these parameters influence the vibration is done based on...
Modal analysis is an important step in optimal design of the spindle. Speedy cotton spindles of JW.D3203 are studied in this paper. The structural features of the spindle are described. ANSYS finite element analysis software is used for modeling of the spindle. Setting material properties, defining element type, meshing, and determining the boundary conditions are done before the top ten mode figures...
In this paper, we present the spectral analysis of the sound recorded from a musical pillar at Vitthala temple, Hampi — a world heritage site. The pillars in this temple have musical columns which produce sounds of different musical instruments when struck with a thumb (i.e., a kind of impulse-like excitation). The sound recorded from a pillar is found to produce bell-like sound. In addition, an analysis...
This paper addresses the development of a new signal processing approach based on the fusion of Hilbert transform and bispectral analysis to extract features of defects in a number of induction motor bearing conditions. The bearing conditions considered are a normal bearing and bearings with outer and inner race faults. The signal processing techniques based on Hilbert transform have been used to...
In order to solve the issue of unsteadiness of coordinator belonging to a transfer system and master the natural frequency and deformation of coordinator, calculations of natural frequency were performed by the method of theory calculation and FEM software ANSYS. Accuracy of the model was tested and the natural frequency and deformation were studied according to comparing the data obtained by the...
Vibration-induced solder joint failure is one of the common failure modes in microelectronics used in the automotive and the aerospace industries. In most of these applications, printed wiring boards (PWBs) with multiple surface-mount components are attached to a base frame through either sockets, clamps, or receptacles. Since the base frame is typically attached to the vehicle, the vehicle's vibration...
The adaptive fuzzy vibration control problem of large flexible truss with Hexapod active interface is studied. Firstly, independent modal space model of flexible truss with Hexapod active interface is established with energy method. A stable direct adaptive fuzzy controller is designed based on fuzzy control theory and classical adaptive control theory. Finally, flexible truss active vibration control...
The paper presents a FEA method for an aero-engine compressor blade and makes a vibration characteristic analysis of this aero-engine compressor blade using this method. Computations are carried out to get the natural modal and corresponding frequencies of this compressor blade. The first eight natural frequencies and mode shapes are obtained and the vibration characteristics of this aero-engine compressor...
As it is difficult to modelize the vibration active control of smart structure. Piezoelectric equations and the elastic mechanics equations are adopted to establish the electromechanical coupling finite element equations and dynamics equations of suspension smart structure with piezoelectric actuators. Then the finite element model of smart structure vibration control can be finally established. Since...
The surge fault is the severe fault of the mine main ventilator. In order to improve the reliability of the surge diagnosis of the mine main ventilator, this paper presents a new surge diagnosis method based on the multi-sensor information fusion. A novel calculating method of the mass function based on the fuzzy set is put forward. According to the characteristics of the surge diagnosis of the mine...
Tuned Mass Dampers dissipate vibratory energy through a set of damper and spring connecting a small mass to the main structure; they have a great effect in vibration suppression caused by low frequency loads and loads with frequencies near the structure's fundamental frequency. Despite these advantages they have shown poor behavior due to stochastic loads with high frequencies such as earthquakes...
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