Computer Analysis of the Dynamic Contact Behavior and Tracking Characteristics of a Single-Degree-of-Freedom Slider Model for a Contact Recording Head

1995 ◽  
Vol 117 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Kyosuke Ono ◽  
Hiroshi Yamamura ◽  
Takaaki Mizokoshi
Keyword(s):  
Contact Stiffness ◽  
Time History ◽  
Dynamic Contact ◽  
Disk Surface ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Single Degree Of Freedom ◽  
Contact Behavior ◽  
Single Degree ◽  
Contact Slider

This paper presents a new theoretical approach to the dynamic contact behavior and tracking characteristics of a contact slider that is one of the candidates of head design for future high density magnetic recording disk storages. A slider and its suspension are modeled as a single-degree-of-freedom vibration system. The disk surface is assumed to have a harmonic wavy roughness with linear contact stiffness and damping. From the computer simulation of the time history of the slider motion after dropping from the initial height of 10 nm, it is found that the contact vibration of the slider can attenuate and finally track on the wavy disk surface in a low waviness frequency range. As the waviness frequency increases, however, the slider cannot stay on the disk surface and comes to exhibit a variety of contact vibrations, such as sub- and super-harmonic resonance responses and finally comes to exhibit non-periodic vibration. It is also found that, among design parameters, the slider load to mass ratio and contact damping can greatly increase the surface waviness frequency and amplitude for which the stable tracking of a contact slider is possible.

Analysis of Bouncing Vibrations of a 2-DOF Tripad Contact Slider Model With Air Bearing Pads Over a Harmonic Wavy Disk Surface

1999 ◽  
Vol 121 (4) ◽  
pp. 939-947 ◽  
Author(s):  
Kyosuke Ono ◽  
Kan Takahashi
Keyword(s):  
Contact Stiffness ◽  
Disk Surface ◽  
Design Parameters ◽  
Air Bearing ◽  
Static Contact ◽  
Tracking Ability ◽  
The Coefficient Of Friction ◽  
Bearing Stiffness ◽  
Perfect Contact ◽  
Contact Slider

In this study, the authors numerically analyzed the bouncing vibrations of a two-degree-of-freedom (2-DOF) model of a tripad contact slider with air bearing pads over a harmonic wavy disk surface. The general features of bouncing vibrations were elucidated in regard to the modal characteristics of a 2-DOF vibration system and design parameters such as contact stiffness, contact damping, air hearing stiffness, the rear to front air bearing stiffness ratio, static contact force and the coefficient of friction. The design of a contact slider was discussed in terms of tracking ability and wear durability. In addition, two sample designs of a perfect contact slider with sufficient wear durability were also presented.

scholarly journals Miura-ori, Basics for Designing its Folding Machines

2019 ◽  
Vol 2 ◽  
pp. 1-5
Author(s):  
Koryo Miura
Keyword(s):  
Basic Concept ◽  
High Speed ◽  
Geometric Property ◽  
Unique Property ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Geometric Properties ◽  
Single Degree Of Freedom ◽  
Single Degree

<p><strong>Abstract.</strong> The unique property of the Miura-ori map is due to the geometric property of “the single degree of freedom”. With this, one can open a map with a single pull motion. However, due to this property, the high-speed folding machine is difficult to realized. In this presentation, author investigates the natural geometric properties of Miura-ori in detail and proposes a basic concept for designing its folding machine. Though, the result does not provide a draft of a folding machine, the basics for the design parameters is beneficial for future works.</p>

Computer Analysis of Bouncing Vibration and Tracking Characteristics of a Point Contact Slider Model Over Random Disk Surfaces

1999 ◽  
Vol 121 (3) ◽  
pp. 587-595 ◽  
Author(s):  
Kyosuke Ono ◽  
Kan Takahashi ◽  
Kohei Iida
Keyword(s):  
Contact Stiffness ◽  
Point Contact ◽  
Disk Surface ◽  
Design Parameters ◽  
Random Surface ◽  
Disk Interface ◽  
Tracking Ability ◽  
Interface Parameters ◽  
Parameter Values ◽  
Contact Slider

This study is a computational analysis of the bouncing vibration of a point contact slider model over computer generated random disk surfaces and the design conditions of slider to disk interface parameters necessary for contact recording. The Gaussian random surface of a disk with various standard deviations and frequency characteristics is generated by using a modified midpoint displacement algorithm. From the calculated results of bouncing vibration of a slider for various parameter values, it was found that the decrease in contact stiffness and increase in slider load can significantly reduce the bouncing vibration as well as the increase in contact damping and the smoothness of the surface. It was also found that the bouncing vibration spectrum of a contact slider over a simulated disk surface agreed closely with the experimental results presented in a previous study by the authors. The maximum and rms values of the spacing and the contact force were examined for various design parameters. The design conditions of the contact pad to the disk interface were discussed in terms of tracking ability and wear durability for slider loads of 0.5 mN and 5 mN.

Design Tool for Base-Isolated Structures Modeled as Single-Degree-of-Freedom Oscillators

1997 ◽  
Vol 50 (11S) ◽  
pp. S125-S132
Author(s):  
Gustavo O. Maldonado
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Design Tool ◽  
Degree Of Freedom ◽  
Iteration Step ◽  
Complex Conjugate ◽  
Equivalent Linearization ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Isolated Structures

A stochastic equivalent linearization technique combined with a ground response spectrum approach is proposed to approximate the inelastic response of base-isolated structures. These structures are modeled by nonlinear oscillators with a single degree of freedom. The main advantage of the proposed methodology is the fast calculation of approximate results in comparison with the slow, but more accurate time history analyses. The Bouc-Wen constitutive model is used to represent the inelastic behavior of the isolators. The equations of motion are linearized by an iterative stochastic technique involving the a-priori unknown response statistics. At each iteration step, the modal contributions from one real and one pair of complex conjugate modes are combined by a response spectrum approach to obtain the maximum responses of interest. The process requires the use of conventional spectra (pseudo-acceleration and relative velocity) as well as the relative displacement spectrum of a massless oscillator. Floor response spectrum results above the isolators are calculated by the proposed approach and are compared against the results obtained by a simulation involving time history analyses.

A Finite-Element-Based Method to Determine the Spatial Stiffness Properties of a Notch Hinge

1998 ◽  
Vol 123 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Shilong Zhang ◽  
Ernest D. Fasse
Keyword(s):  
Finite Element ◽  
Finite Element Methods ◽  
Joint Stiffness ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Stiffness Properties ◽  
Six Degree Of Freedom ◽  
Flexural Hinges

Notch hinges are flexural hinges used to make complex, precise mechanisms. They are typically modeled as single degree-of-freedom hinges with an associated joint stiffness. This is not adequate for all purposes. This paper computes the six degree-of-freedom stiffness properties of notch hinges using finite element methods. The results are parameterized in terms of meaningful design parameters.

scholarly journals Development of equivalent linear systems for single-degree-of-freedom structures with magneto-rheological dampers for seismic design application

2017 ◽  
Vol 28 (19) ◽  
pp. 2675-2687 ◽  
Author(s):  
Yunbyeong Chae ◽  
James M Ricles ◽  
Richard Sause
Keyword(s):  
Response Spectrum ◽  
Damping Ratio ◽  
Time History ◽  
Analysis Procedure ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Design Response Spectrum ◽  
Simplified Analysis ◽  
Magneto Rheological

Numerous studies have been conducted for magneto-rheological dampers, but the application of magneto-rheological dampers in seismic design is limited due to the lack of a systematical design procedure. In this article, a simplified analysis procedure is proposed to estimate the response of a single-degree-of-freedom structure with diagonal bracing and a magneto-rheological damper without performing the time history analysis. The proposed simplified analysis procedure is based on the equivalent linear system of a magneto-rheological damper. The equivalent damping ratio and the effective period of the single-degree-of-freedom system are determined from the loss factor and the effective stiffness of the magneto-rheological damper based on the quasi-static model. Design response spectrum is utilized to calculate the displacement of the single-degree-of-freedom system. The equivalent damping ratio and the effective stiffness of the single-degree-of-freedom system are dependent on the displacement of the system; thus, the proposed procedure is iterated until the displacement from the design response spectrum converges. The accuracy of the simplified analysis procedure is evaluated by comparing the estimated response from this procedure with the response from the time history analysis. The results show a good agreement between two methods, demonstrating the robustness of the proposed simplified analysis procedure.

Study on Evaluation Method of High-Rise Building Performance by Equivalent Single Degree of Freedom System

2008 ◽  
Vol 400-402 ◽  
pp. 599-605
Author(s):  
Xing Wen Liang ◽  
Li Xin ◽  
Yue Sheng Tong
Keyword(s):  
Evaluation Method ◽  
Demand Curve ◽  
Time History ◽  
Degree Of Freedom ◽  
Nonlinear Time History Analysis ◽  
Elastic Displacement ◽  
Natural Period ◽  
Single Degree Of Freedom ◽  
High Rise ◽  
Single Degree

A performance evaluation method of high-rise buildings is presented, by means of capacity spectra method which allows for higher mode effects. The multi-degree-of-freedom system (MDOF) of each mode is transformed into equivalent single-degree-of-freedom (ESDOF) system, and the ESDOF system is supposed to be elastic perfectly plastic. In elastic range, the equivalent displacement of ESDOF system for each mode is deduced by displacement response spectra based on the natural period, and the structural lateral elastic displacement of each mode could be determined by the corresponding equivalent displacement and mode shape. In inelastic range, according to capacity spectra method, the relationships among demand curve, capacity curve and ductility coefficient are built. The structural performance under moderate or major earthquake is determined by iteration method. The paper illustrates the application of the proposed procedure with an example and attempts to prove its feasibility by nonlinear time-history analysis.

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