Influence Of Vibration Modes Research Articles

Estimating the segregation of a granular bed subjected to vibration in various modes

We present in this paper a DEM study on the segregation behavior of vibrated binary mixture, by focusing on the influence of vibration modes. The numerical simulation program includes a number of vibration tests on a binary mixture in a cylindrical bed, which are performed under different vibration velocity modes, frequencies and amplitudes. We utilize a novel segregation index, namely, the graphic segregation index (GPSI), to characterize the segregation behavior and trace the segregation evolution for binary mixtures. The numerical simulations reveal that the influence of velocity mode is coupled with that resulting from vibration frequency. The binary mixture tends to segregate at a low frequency, with little influence exerted by the velocity mode, whereas it does not fulfill complete segregation at a relatively high frequency, with the vibration frequency having some limited impact on the segregation behavior. Given an intermediate frequency the segregation behavior of the mixture is a little mixed for various velocity modes. It is also found that increasing vibration amplitude enhances the segregation degree of binary mixture. The operation of percolation mechanism in the broad sense is assumed to be primarily responsible for the occurrence of segregation in this study, and this alleged percolation mechanism, as an overall effect, is a result of three effects: the random gap effect, the size-and-mass dependent acceleration and the intrusion and expulsion effect.

Structural Dynamic Analysis of Freight Railway Wagon Using Finite Element Method

This paper describes the development of a virtual freight wagon vehicle using virtual prototyping computer tools. The freight wagon considered as open type wagon “BOXN25” of the Indian Railways. The freight wagon vehicle comprises of car body structure and two bogies. Solidworks is used for modeling the freight wagon and the geometry is exported to finite element tool, ANSYS. A multi degree of freedom system has been reviewed and compared with system having infinite degree of freedom (continuous structure). The current problem falls in the category of large models (Block Lanczos Algorithm is used) and has high degrees of freedom (PCG Solver is used). The structural dynamic response for the virtual freight wagon is determined. It is seen that the car body deformation is influenced by its elastic underframe and sidewalls. The influence of vibration modes, which describe local deflection, on the comfort level and stability of laden goods is discussed. Mode shapes up to a frequency of 30Hz are considered.

Influence of vibrational modes on quantum transport through a nanodevice

We employ the recently proposed scattering states numerical renormalization group (SNRG) approach to calculate $I(V)$ and the differential conductance through a single molecular level coupled to a local molecular phonon using the spinless Anderson-Holstein model. We also discuss the equilibrium physics of the model and demonstrate that the low-energy Hamiltonian is given by an effective interacting resonant level model. From the NRG level flow, we directly extract the effective charge transfer scale ${\ensuremath{\Gamma}}_{\mathrm{eff}}$ and the dynamically induced capacitive coupling ${U}_{\mathrm{eff}}$ between the molecular level and the lead electrons, which turns out to be proportional to the polaronic energy shift ${E}_{p}$ for the regimes investigated here. The equilibrium spectral functions for the different parameter regimes are discussed. The additional phonon peaks at multiples of the phonon frequency ${\ensuremath{\omega}}_{0}$ correspond to additional maxima in the differential conductance. Nonequilibrium effects, however, lead to significant deviations between a symmetric junction and a junction in the tunnel regime. The suppression of the current for particle-hole asymmetric junctions with increasing electron-phonon coupling, the hallmark of the Franck-Condon blockade, is discussed.

Influence of vibration mode on the screening process

The screening of particles with different vibration modes was simulated by means of a 3D discrete element method (3D-DEM). The motion and penetration of the particles on the screen deck were analyzed for linear, circular and elliptical vibration of the screen. The results show that the travel velocity of the particles is the fastest, but the screening efficiency is the lowest, for the linear vibration mode. The circular motion resulted in the highest screening efficiency, but the lowest particle travel velocity. In the steady state the screening efficiency for each mode is seen to increase gradually along the longitudinal direction of the deck. The screening efficiency increment of the circular mode is the largest while the linear mode shows the smallest increment. The volume fraction of near-mesh size particles at the underside is larger than that of small size particles all along the screen deck. Linear screening mode has more near-mesh and small size particles on the first three deck sections, and fewer on the last two sections, compared to the circular or elliptical modes.

Features and Applications of Tennis Racket

The study introduced tennis rackets and listed their categories firstly. The purpose was to analyze features of tennis racket. This study showed the influence of vibration mode on response of tennis rackets and Player sensitivity to changes in string tension in a tennis racket. Combining bounce of a tennis ball, made out the applications of tennis racket: a analysis of the ball and racket during first and second tennis serves.

Influence of Vibration Modes and Human Operator on the Stability of Haptic Rendering

Developing stable controllers, which are able to display virtual objects with high stiffness, is a persistent challenge in the field of haptics. This paper addresses the effect of internal vibration modes and the human operator on the maximum achievable virtual stiffness. An 11-parameter mechanical model is used to adequately characterize the overall system dynamics. Experiments that are carried out on LHIfAM and PHANToM haptic interfaces demonstrate the importance of vibration modes to determine the critical stiffness when the user grasps the device.

Modal-based model reduction and vibration control for uncertain piezoelectric flexible structures

In piezoelectric flexible structures, the contribution of vibration modes to the dynamic response of system may change with the location of piezoelectric actuator patches, which means that the ability of actuators to control vibration modes should be taken into account in the development of modal reduction model. The spatial H2 norm of modes, which serves as a measure of the intensity of modes to system dynamical response, is used to pick up the modes included in the reduction model. Based on the reduction model, the paper develops the state-space representation for uncertain flexible structures with piezoelectric material as non-collocated actuators/sensors in the modal space, taking into account uncertainties due to modal parameters variation and unmodeled residual modes. In order to suppress the vibration of the structure, a dynamic output feedback control law is designed by simultaneously considering the conflicting performance specifications, such as robust stability, transient response requirement, disturbance rejection, actuator saturation constraints. Based on linear matrix inequality, the vibration control design is converted into a linear convex optimization problem. The simulation results show how the influence of vibration modes on the dynamical response of structure varies with the location of piezoelectric actuators, why the uncertainties should be considered in the reductiom model to avoid exciting high-frequency modes in the non-collcated vibration control, and the possiblity that the conflicting performance specifications are dealt with simultaneously.

Influence of vibrational modes on the electronic properties of DNA

We investigate the electron (hole) transport through short double-stranded DNA wires in which the electrons are strongly coupled to the specific vibrational modes (vibrons) of the DNA. We analyze the problem starting from a tight-binding model of DNA, with parameters derived from ab initio calculations, and describe the dissipative transport by equation-of-motion techniques. For homogeneous DNA sequences like poly-(guanine-cytosine), we find the transport to be quasiballistic with an effective density of states which is modified by the electron-vibron coupling. At low temperatures, the linear conductance is strongly enhanced, but above the ``semiconducting'' gap it is much less affected. In contrast, for inhomogeneous (``natural'') sequences, almost all states are strongly localized and transport is dominated by dissipative processes. In this case, a nonlocal electron-vibron coupling influences the conductance in a qualitative and sequence-dependent way.

Neutron and light scattering study of supercooled glycerol.

Relaxation dynamics was investigated in the hydrogen-bonded glass former glycerol using incoherent neutron scattering and depolarized light scattering. The neutron data have a q-independent form in the intermediate \ensuremath{\beta}-relaxation regime implying factoratization of the q and \ensuremath{\omega} dependences. Similar susceptibility spectra obtained from both data sets qualitatively resembling the mode coupling theory scenario. Quantitative fits indicate apparent deviations of the exponents from mode coupling theory predictions suggesting that the influence of vibrational modes is severe in network glass formers.

Flexibility Control of Flexible Structures. 6th Report. Asymptotic Covergence of Learning Process in Neural Network Controller Considering Spillover.

This paper deals with trajectory control of a flexible plate handling system using the neural network learning method. The conditions for the asymptotic convergence of the feedback error learning method for each trial are obtained. The influence of vibration modes not modeled on the conditions for the asymptotic convergence is discussed. Based on the result, obtained here, we present a fast learning method for trajectory control of a flexible plate handling system. The control system consists of a low-pass filter and two neural networks. The learning method is to change the learning rate according to the convergence conditions. A one-joint robot handling flexible plate is simulated, and the simulation results show the effectiveness of the proposed conditions and learning method.

Influence of vibration mode and orientation of deformed nucleus on the deflection function in heavy ion reactions

Influence of vibration mode and orientation of deformed nucleus on the deflection function in heavy ion reactions