scholarly journals New Designs of HDD Air-Lubricated Sliders Via Topology Optimization

2004 ◽  
Vol 126 (1) ◽  
pp. 171-176 ◽  
Author(s):  
Chung-Jen Lu ◽  
Tai-Kuo Wang
Keyword(s):  
Topology Optimization ◽  
Optimal Design ◽  
Hard Disk Drives ◽  
Optimal Solution ◽  
Optimization Method ◽  
Uniform Mesh ◽  
Optimal Size ◽  
Air Bearing ◽  
Bearing Surface ◽  
Initial Design

Optimization is an efficient tool for developing designs of slider air bearings that meet the strict performance demands of current hard disk drives. Previous studies in this field concentrated on determining the optimal size and shape of the air-bearing surface for a specified initial design. The resulting optimal design has the same topology as that of the initial design. Therefore, the performance of the final optimal solution depends strongly on the initial design, which is chosen either intuitively or inspired by already existing designs. In this study, a topology optimization method is developed for determining the optimal slider configuration. First, the air-bearing surface is discretized by a uniform mesh. The optimization consists in determining whether the material contained in each element should be removed or not. Then, a genetic algorithm is employed for the determination of the optimal solution from the possible candidates. An example is presented to demonstrate the effectiveness of the proposed approach. The resulting optimal design has a topology different from those of the initial designs and possesses improved performance.

An Optimization Method for Design of Subambient Pressure Shaped Rail Sliders

1999 ◽  
Vol 121 (3) ◽  
pp. 575-580 ◽  
Author(s):  
Dong-Hoon Choi ◽  
Tae-Sik Kang
Keyword(s):  
Design Methodology ◽  
Optimization Method ◽  
Flying Height ◽  
Air Bearing ◽  
Bearing Surface ◽  
Programming Technique ◽  
Design Synthesis ◽  
Method Of Feasible Directions ◽  
Design Variables ◽  
Simulation Results

This study proposes a design methodology for determining configurations of subamient pressure shaped rail sliders by using a nonlinear programming technique in order to meet the desired flying characteristics over the entire recording band. The desired flying characteristics considered in this study are to minimize the variation in flying height from a target value, to keep the pitch angle within a suitable range, and to ensure that the outside rail flies lower than the inside rail even with the roll distribution due to manufacturing process. The design variables selected are recess depth, geometry of the air bearing surface, and pivot location in the transverse direction of the slider. The method of feasible directions in Automated Design Synthesis (ADS) is utilized to automatically find the optimum design variables which simultaneously meet all the desired flying characteristics. To validate the suggested design methodology, a computer program is developed and applied to a 30 percent/15 nm twin rail slider and a 30 percent/15 nm tri-rail slider. Simulation results for both sliders demonstrated the effectiveness of the proposed design methodology by showing that the flying characteristics of the optimally designed sliders are enhanced in comparison with those of the initial ones.

scholarly journals Parametric Investigations at the Head-Disk Interface of Thermal Fly-Height Control Sliders in Contact

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Sripathi V. Canchi ◽  
David B. Bogy ◽  
Run-Han Wang ◽  
Aravind N. Murthy
Keyword(s):  
Hard Disk Drives ◽  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Surface Design ◽  
Disk Interface ◽  
Height Control ◽  
Experimental Findings ◽  
And Control ◽  
Fly Height

Accurate touchdown power detection is a prerequisite for read-write head-to-disk spacing calibration and control in current hard disk drives, which use the thermal fly-height control slider technology. The slider air bearing surface and head gimbal assembly design have a significant influence on the touchdown behavior, and this paper reports experimental findings to help understand the touchdown process. The dominant modes/frequencies of excitation at touchdown can be significantly different leading to very different touchdown signatures. The pressure under the slider at touchdown and hence the thermal fly-height control efficiency as well as the propensity for lubricant pickup show correlation with touchdown behavior which may be used as metrics for designing sliders with good touchdown behavior. Experiments are devised to measure friction at the head-disk interface of a thermal fly-height control slider actuated into contact. Parametric investigations on the effect of disk roughness, disk lubricant parameters, and air bearing surface design on the friction at the head-disk interface and slider burnishing/wear are conducted and reported.

Boundary Effect on Particle Motion in the Head Disk Interface

2007 ◽  
Author(s):  
Nan Liu ◽  
David B. Bogy
Keyword(s):  
Drag Force ◽  
Particle Motion ◽  
Boundary Effect ◽  
Hard Disk Drives ◽  
Areal Density ◽  
Air Bearing ◽  
Disk Drives ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Disk Interface

Simulation of particle motion in the Head Disk Interface (HDI) helps to understand the contamination process on a slider, which is critical for achieving higher areal density of hard disk drives. In this study, the boundary effect—the presence of the slider and disk—on particle motion in the HDI is investigated. A correction factor to account for this effect is incorporated into the drag force formula for particles in a flow. A contamination criterion is provided to determine when a particle will contaminate a slider. The contamination profile on a specific Air Bearing Surface is obtained, which compares well with experiments.

1114 Level Set-based Topology Optimization Method for Optimal Design of Flow Channel

2013 ◽  
Vol 2013.23 (0) ◽  
pp. _1114-1_-_1114-9_
Author(s):  
Kentaro YAJI ◽  
Takayuki YAMADA ◽  
Masato YOSHINO ◽  
Toshiro MATSUMOTO ◽  
Kazuhiro IZUI ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Optimal Design ◽  
Level Set ◽  
Optimization Method ◽  
Flow Channel ◽  
Topology Optimization Method

Optimal Design of a Mechanism Used for Opening and Shutting a Ship’s Hatch Cover

1984 ◽  
Vol 106 (4) ◽  
pp. 503-509
Author(s):  
Koichi Ito ◽  
Tadashi Kuroiwa ◽  
Shinsuke Akagi
Keyword(s):  
Optimal Design ◽  
Nonlinear Optimization ◽  
Optimization Problem ◽  
Numerical Study ◽  
Optimal Solution ◽  
Optimization Method ◽  
Gradient Algorithm ◽  
Linkage Mechanism ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient

A nonlinear optimization method is proposed to design a linkage mechanism used for opening and shutting a ship’s hatch cover. Considering the maximum force of the oil cylinder necessary to move the hatch cover as the objective function to be minimized, the design problem to determine the optimal configuration of linkage mechanism is formulated as a nonlinear optimization problem of minimax type. It it shown that the optimal solution can be derived by adopting the generalized reduced gradient algorithm together with a linkage statical simulation model, and the effectiveness of the algorithm is ascertained through a numerical study.

Design of material microstructures for maximum effective elastic modulus and macrostructures

2018 ◽  
Vol 35 (2) ◽  
pp. 622-640 ◽  
Author(s):  
Daicong Da ◽  
Xiangyang Cui ◽  
Kai Long ◽  
Guanxin Huang ◽  
Guangyao Li
Keyword(s):  
Topology Optimization ◽  
Optimal Design ◽  
Optimization Algorithm ◽  
Strain Energy ◽  
Optimal Solution ◽  
Material Design ◽  
Structural Performance ◽  
Pure Material ◽  
Content Type ◽  
Computational Performance

PurposeIn pure material design, the previous research has indicated that lots of optimization factors such as used algorithm and parameters have influence on the optimal solution. In other words, there are multiple local minima for the topological design of materials for extreme properties. Therefore, the purpose of this study is to attempt different or more concise algorithms to find much wider possible solutions to material design. As for the design of material microstructures for macro-structural performance, the previous studies test algorithms on 2D porous or composite materials only, it should be demonstrated for 3D problems to reveal numerical and computational performance of the used algorithm.Design/methodology/approachThe presented paper is an attempt to use the strain energy method and the bi-directional evolutionary structural optimization (BESO) algorithm to tailor material microstructures so as to find the optimal topology with the selected objective functions. The adoption of the strain energy-based approach instead of the homogenization method significantly simplifies the numerical implementation. The BESO approach is well suited to the optimal design of porous materials, and the generated topology structures are described clearly which makes manufacturing easy.FindingsAs a result, the presented method shows high stability during the optimization process and requires little iterations for convergence. A number of interesting and valid material microstructures are obtained which verify the effectiveness of the proposed optimization algorithm. The numerical examples adequately consider effects of initial guesses of the representative unit cell (RUC) and of the volume constraints of solid materials on the final design. The presented paper also reveals that the optimized microstructure obtained from pure material design is not the optimal solution any more when considering the specific macro-structural performance. The optimal result depends on various effects such as the initial guess of RUC and the size dimension of the macrostructure itself.Originality/valueThis paper presents a new topology optimization method for the optimal design of 2D and 3D porous materials for extreme elastic properties and macro-structural performance. Unlike previous studies, the presented paper tests the proposed optimization algorithm for not only 2D porous material design but also 3D topology optimization to reveal numerical and computational performance of the used algorithm. In addition, some new and interesting material microstructural topologies have been obtained to provide wider possible solutions to the material design.

Topology and Size–Shape Optimization of an Adaptive Compliant Gripper with High Mechanical Advantage for Grasping Irregular Objects

Robotica ◽  
2019 ◽  
Vol 37 (08) ◽  
pp. 1383-1400 ◽  
Author(s):  
Chih-Hsing Liu ◽  
Chen-Hua Chiu ◽  
Mao-Cheng Hsu ◽  
Yang Chen ◽  
Yen-Pin Chiang
Keyword(s):  
Topology Optimization ◽  
Optimal Design ◽  
Shape Optimization ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Experimental Studies ◽  
Design Procedure ◽  
Optimization Methods ◽  
Optimization Method ◽  
Mechanical Advantage

SummaryThis study presents an optimal design procedure including topology optimization and size–shape optimization methods to maximize mechanical advantage (which is defined as the ratio of output force to input force) of the synthesized compliant mechanism. The formulation of the topology optimization method to design compliant mechanisms with multiple output ports is presented. The topology-optimized result is used as the initial design domain for subsequent size–shape optimization process. The proposed optimal design procedure is used to synthesize an adaptive compliant gripper with high mechanical advantage. The proposed gripper is a monolithic two-finger design and is prototyped using silicon rubber. Experimental studies including mechanical advantage test, object grasping test, and payload test are carried out to evaluate the design. The results show that the proposed adaptive complaint gripper assembly can effectively grasp irregular objects up to 2.7 kg.

Optimization of Proximity Recording Air Bearing Sliders in Magnetic Hard Disk Drives

1999 ◽  
Vol 122 (1) ◽  
pp. 257-259 ◽  
Author(s):  
Matthew A. O’Hara ◽  
Yong Hu ◽  
David B. Bogy
Keyword(s):  
Numerical Optimization ◽  
Tribological Behavior ◽  
Contact Stiffness ◽  
Hard Disk Drives ◽  
Tribological Performance ◽  
Air Bearing ◽  
Disk Drives ◽  
Bearing Surface ◽  
Magnetic Hard Disk ◽  
Made In

The object of this paper will be to optimize the contact stiffness (CS) of an existing proximity recording air bearing surface (ABS). The CS is a measure of the slider’s increase in contact force with increase in slider/disk interference. By minimizing this, the amount of force transmitted through the slider at the interface is minimized. This should, in turn, minimize the amount of wear, improving the tribological performance. Comparisons of the pre- and post-optimized slider have been made. In combination with research that demonstrates the ability of the CS parameter to predict tribological behavior (Hu et al., ASME J. Tribol., 120, pp. 272–279) this paper demonstrates the feasibility of numerical optimization of the tribological behavior of proximity recording air bearing sliders. [S0742-4787(00)03201-X]

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