On Coupled Dynamics of Frictional Guides in Tape Transport Systems

2014 ◽  
Author(s):  
Hankang Yang ◽  
Sinan Müftü
Keyword(s):  
Mathematical Model ◽  
Transport Systems ◽  
Tape Recording ◽  
Tape Transport ◽  
Resonant Frequencies ◽  
Lateral Tape Motion ◽  
Frictional Damping ◽  
Data Tape ◽  
Lateral Friction ◽  
Frictional Effects

Stationary guides introduce friction on to a travelling tape in the longitudinal and lateral directions. The longitudinal friction increases the tape tension and the lateral friction dampens the lateral tape motion (LTM). A comprehensive mathematical model of the coupled longitudinal and lateral tape dynamics is developed. Frictional effects over a cylindrical guide are modeled as concentrated loads in both longitudinal and lateral directions. In the range of tape transport velocities that are of interest to data tape recording, it was shown that frictional damping causes reduction of resonant frequencies and resonance amplitudes. Positioning of the guiding elements could significantly influence the dynamic response of LTM.

The Effect of Hertzian, Bending and Shearing Stiffness on Noise and Vibration

2001 ◽  
Author(s):  
Jamil Abdo ◽  
Kambiz Farhang ◽  
Mousa Mohsen
Keyword(s):  
Mathematical Model ◽  
Contact Stiffness ◽  
Hertzian Contact ◽  
Hertz Contact ◽  
Resonant Frequencies ◽  
Tangential Contact ◽  
Apparent Stiffness ◽  
Fundamental Understanding ◽  
The Mathematical Model ◽  
Friction Induced Vibration

Abstract Since the apparent stiffness due to contact of one surface on another relates directly to the localized resonant frequencies, it is believed that accurate account of this property will lead to the fundamental understanding of causes of friction-induced vibration and noise. The mathematical model of contact is utilized to develop formulae for normal and tangential contact stiffness. The inclusion of a study in which the various modes of elastic deflections of an asperity are also considered, as well as their effects. The bending, shear and Hertz contact modes of elastic deflection are assumed to simultaneously occur for an asperity. Investigation of the combined effect of bending, shear and Hertzian contributions to the contact stiffness is indicating that the equivalent contact stiffness is best represented, among the three types of stiffness, by that due to Hertzian contact.

Characterization and Simulation of MIMO Transport Systems in Tape

2013 ◽  
Author(s):  
Giovanni Cherubini ◽  
Angeliki Pantazi ◽  
Jens Jelitto
Keyword(s):  
Block Diagram ◽  
Lateral Position ◽  
Transport Systems ◽  
Tape Transport ◽  
Channel One ◽  
Performance Improvements ◽  
Improved Performance ◽  
The Individual ◽  
Hall Sensors ◽  
Longitudinal Position

The potential for significant capacity and performance improvements in tape storage systems appears to be substantial [1],[2]. Advances in several areas, however, are necessary to foster increases in linear and track densities and consequently achieve higher cartridge capacities and improved performance [3],[4]. Reliable and precise tape transport and track-following servomechanisms are of fundamental importance to guarantee best read-channel performance on all parallel data channels during tape operation. In particular, tight control of tension and potentially of tape-dimensional stability (TDS) variations will be necessary for moving to thinner tape material, which in turn will enable an increase in volumetric density. Figure 1 shows the block diagram of conventional tape transport and track-following servomechanisms in a tape drive [5]. A digital dual servo channel provides estimates of the tape velocity, tape longitudinal position, and head lateral position, which are derived from signals read from dedicated servo bands [6]. Hall sensors provide tape velocity information from the individual reels, which typically is used in the absence of a valid velocity estimate from the servo channel. One of the main impairments affecting the performance of tape drives is the variation of tape tension [7],[8], which may be induced by, e.g., reel eccentricities.

Calculation of the Parameters of a Mathematical Model of an Electric Hybrid Stepper Motor Based on the Analysis of the Magneto Static Field Pattern

2019 ◽  
Vol 20 (8) ◽  
pp. 482-489
Author(s):  
S. V. Volkov ◽  
O. V. Goryachev ◽  
A. G. Efromeev ◽  
A. O. Stepochkin
Keyword(s):  
Mathematical Model ◽  
Natural Frequency ◽  
Electric Drive ◽  
Magnetic Circuit ◽  
Stepper Motor ◽  
Design Parameters ◽  
System Of Equations ◽  
Magnetostatic Field ◽  
Resonant Frequencies ◽  
Electromagnetic Moment

The article presents a solution to the problem of calculating the parameters of a mathematical model of an electric hybrid stepper motor based on an analysis of the picture of its magnetostatic field. The main disadvantage of such an engine described. Is the mid-frequency resonance, which occurs due to the coincidence of the natural frequency of the rotor with the frequency of the supply voltage pulses. The necessity of taking this factor into account when designing a discrete electric drive system based on the executive motor of this type by calculating the values of resonant frequencies and using them in developing the drive control algorithm is shown. The task of developing a mathematical model of the engine is formulated, which allows to analyze the influence of its design parameters on the spectrum of resonant frequencies. The method of calculating the parameters of a given mathematical model is formed. The variants of the mathematical description of this electric machine are considered and the selection of its known mathematical model is made based on the equivalent electric circuit. The numerical calculation of the spatial pattern of the magnetostatic field of the electric motor is performed. Based on the analysis of the calculation results, a system of assumptions has been formed to develop an equivalent magnetic circuit of an electrical machine. An equivalent magnetic circuit and the corresponding system of equations has been developed. Formed a system of equations of a mathematical model based on the equivalent circuits of the electric and magnetic circuits.On the basis of the obtained system of equations, a simulation model of a discrete electric drive was developed in the Simulink software package. Using the obtained simulation model, the calculation of transients on the angle of rotation of the rotor and the electromagnetic moment is carried out and the influence of one of the design parameters on the natural frequency of the rotor is analyzed. Based on the simulation results, it is shown that with an increase in the air gap height of a hybrid stepper motor, the resulting electromagnetic moment decreases, and the natural oscillation frequency of the rotor decreases, and the frequency at which medium-frequency resonance occurs also decreases. This mathematical model can be used at the stage of the correct calculation of the selected engine, since allows you to analyze the effect of a specific design parameter of the machine — in particular the size of the air gap on the natural frequency of the rotor, and, consequently, on the spectrum of the resonant frequencies of a discrete electric drive.

Development of methodology bases of the network mathematical models transportation and technological flows timber.

2017 ◽  
Vol 6 (2) ◽  
pp. 63-68
Author(s):  
Бурмистрова ◽  
Olga Burmistrova ◽  
Пильник ◽  
Yuliya Pilnik
Keyword(s):  
Mathematical Model ◽  
Quality Management ◽  
Mathematical Models ◽  
Transport Systems ◽  
Object Model ◽  
Optimal Solutions ◽  
Mechanical Modeling ◽  
High Quality ◽  
The Mathematical Model ◽  
Selection Of

The mathematical-mechanical modeling - is the study of complex transport systems (processes) through on-the structure and the research object model. Mathematical models allow a pre-selection of optimal solutions according to specific criteria. These scientifically based and are designed to help leaders in the development, validation and acceptance of efficient, high-quality management decisions in the forest complex. But it must be a pony-mother, that any solution obtained by calculating the mathematical model, optimal only for one or more criteria.

On Forced Vibration of Shrouded Turbine Blades

2003 ◽  
Author(s):  
J. Szwedowicz ◽  
W. Sextro ◽  
R. Visser ◽  
P. A. Masserey
Keyword(s):  
Forced Vibration ◽  
Close Agreement ◽  
Turbine Blades ◽  
Normal Vector ◽  
Blade Design ◽  
Air Jet ◽  
Numerical Predictions ◽  
Linear Behavior ◽  
Frictional Damping ◽  
Frictional Effects

Numerical predictions of the forced vibration of a disc assembly including frictional effects between the shrouds are presented concerning engineering needs for the blade design process. Assuming a tuned disc assembly, numerical static, free and then forced vibration analyses of a shrouded turbine blade measured in the spin pit are performed systematically. For the excitation forces of an air jet evaluated from the fairly linear behavior of the experimental blade resonance peaks, the reliability of the proposed approach is validated through the very close agreement of the computed and measured resonant peaks. These resonant peaks demonstrate either a fairly linear behavior or a non-linear one like the jump effect of blade resonance amplitudes, or elastic impacts between the shrouds. Also, the damping performance for different contact configurations between the shrouds is numerically analyzed. These numerical results indicate that the shrouds generate higher frictional damping for small angles (0–30 deg) between the circumferential direction and the normal vector to the contact surface.

Study of Generation Mechanism of Three-Body Particles in Linear Tape Recording

2005 ◽  
Vol 127 (1) ◽  
pp. 155-163 ◽  
Author(s):  
Baogui Shi ◽  
J. L. Sullivan ◽  
M. A. Wild ◽  
S. O. Saied
Keyword(s):  
Photoelectron Spectroscopy ◽  
Tape Recording ◽  
Bearing Surface ◽  
Abrasive Particles ◽  
Force Microscopy ◽  
Atomic Force ◽  
Magnetic Spacing ◽  
Data Tape ◽  
Three Body ◽  
Pole Tip Recession

A major cause of magnetic spacing losses in data tape systems is pole tip recession (PTR). This study is an investigation of PTR in a linear data tape recording system and identification of the mechanisms responsible for these effects, but the results have implications for any head where the tape bearing surface is Al2O3/TiC, AlTiC. Tape cycling experiments were performed using the linear tape open system as the experimental platform with metal particle tape. All experiments were conducted within a matrix of pressure and humidity, which encompassed the system operating extremes. Atomic force microscopy was used to analyze the surface topography of the heads. Auger electron spectroscopy and x-ray photoelectron spectroscopy were employed to analyze the chemical changes on the surface of the heads and tapes. Environment was found to have a significant influence on the head/tape interface. Head wear and PTR was highest at high temperature and humidity. Water vapor was found to transform the surface layers on the TiC grains in the tape-bearing surface to TiO2. This process results in the production of TiO2 fragments that become trapped in the recessed pole tip region, acting as three-body abrasive particles. The TiO2 present on the TiC grains and on the surface of heads increases with the water content after cycling against tapes. The hypothesis is supported by the presence of Ti on the poles.

The Use of Data Tape Recording as a Teaching Aid

1965 ◽  
Vol 26 (5) ◽  
pp. 679-680 ◽  
Author(s):  
DAVID GOWING ◽  
FREDERICK P. HAUGEN
Keyword(s):  
Tape Recording ◽  
Use Of Data ◽  
Teaching Aid ◽  
Data Tape
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