Dynamic response of domain walls on the air‐bearing surface of thin‐film heads

Air layer supported bearing pads, or “air bearings” as they are commonly called, are popular because of their high load capacity and low in-plane coefficient of friction, making them well suited for supporting moving, high accuracy manufacturing stages. Air/vacuum bearings enhance these capabilities by giving the bearing pad load resistance capacity in both the upward and downward directions. Consequently, it is desirable to know how to model the air layer between the bearing pad and the bearing surface. In this paper, a simple finite element modeling approach is presented for investigating the vibrational characteristics of an air layer supported bearing. It was found that by modeling the air layer as a bed of uniform springs who’s stiffness is determined by load-displacement tests of the bearing, a reasonable representation of the response can be obtained. For a bearing supported by air without vacuum, the dynamic response was very similar to that of a freely supported bearing. The addition of vacuum to an air bearing was found to significantly lower its fundamental frequency which could lead to unwanted resonance problems.

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Co-Fe metal/native-oxide multilayers: a new direction in soft magnetic thin film design I. Quasi-static properties and dynamic response

IEEE Transactions on Magnetics ◽

10.1109/tmag.2005.847631 ◽

2005 ◽

Vol 41 (6) ◽

pp. 2043-2052 ◽

Cited By ~ 27

Author(s):

G.S.D. Beach ◽

A.E. Berkowitz

Keyword(s):

Thin Film ◽

Dynamic Response ◽

Native Oxide ◽

Magnetic Thin Film ◽

Static Properties ◽

Soft Magnetic

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Probabilistic Designs of Air-Bearing Surface on Manufacturing Tolerances

ASME/STLE 2004 International Joint Tribology Conference, Parts A and B ◽

10.1115/trib2004-64062 ◽

2004 ◽

Author(s):

Sang-Joon Yoon ◽

Dong-Hoon Choi

Keyword(s):

Design Optimization ◽

Reliability Analysis ◽

Computation Time ◽

Probabilistic Constraints ◽

Air Bearing ◽

Probabilistic Design ◽

Bearing Surface ◽

Deterministic Optimization ◽

Design Variables ◽

Conventional Optimization

The focus in this paper is to automatically design the air-bearing surface (ABS) considering the randomness of its geometry as an uncertainty of design variables. Designs determined by the conventional optimization could only provide a low level of confidence in practical products due to the existence of uncertainties in either engineering simulations or manufacturing processes. This calls for a reliability-based approach to the design optimization, which increases product or process quality by addressing randomness or stochastic properties of design problems. In this study, a probabilistic design problem is formulated considering the reliability analysis which is employed to estimate how the fabrication tolerances of individual slider parameters affect the final flying attitude tolerances. The proposed approach first solves the deterministic optimization problem. Beginning with this solution, the reliability-based design optimization (RBDO) is continued with the probabilistic constraints affected by the random variables. Probabilistic constraints overriding the constraints of the deterministic optimization attempt to drive the design to a reliability solution with minimum increase in the objective. The simulation results of the probabilistic design are directly compared with the values of the initial design and the results of the deterministic optimum design, respectively. In order to show the effectiveness of the proposed approach, the reliability analyses by the Monte Carlo simulation are carried out. And the results demonstrate how efficient the proposed approach is, considering the enormous computation time of the reliability analysis.

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