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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers A
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
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Volume & Issues
Volume 31, Issue 12 - Dec 2007
Volume 31, Issue 11 - Nov 2007
Volume 31, Issue 10 - Oct 2007
Volume 31, Issue 9 - Sep 2007
Volume 31, Issue 8 - Aug 2007
Volume 31, Issue 7 - Jul 2007
Volume 31, Issue 6 - Jun 2007
Volume 31, Issue 5 - May 2007
Volume 31, Issue 4 - Apr 2007
Volume 31, Issue 3 - Mar 2007
Volume 31, Issue 2 - Feb 2007
Volume 31, Issue 1 - Jan 2007
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Eigenvalue and Frequency Response Analyses of a Hard Disk Drive Actuator Using Reduced Finite Element Models
Han, Jeong-Sam ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 541~549
DOI : 10.3795/KSME-A.2007.31.5.541
In the case of control for mechanical systems, it is highly useful to be able to provide a compact model of the mechanical system to control engineers using the smallest number of state variables, while still providing an accurate model. The reduced mechanical model can then be inserted into the complete system models and used for extended system-level dynamic simulation. In this paper, moment-matching based model order reductions (MOR) using Krylov subspaces, which reduce the number of degrees of freedom of an original finite element model via the Arnoldi process, are presented to study the eigenvalue and frequency response problems of a HDD actuator and suspension system.
A Study on the Micro-fracture Behavior of the MEMS Material at Elevated Temperature
Woo, Byung-Hoon ; Bae, Chang-Won ; Moon, Kyong-Man ; Bae, Sung-Yeol ; Higo, Yakichi ; Kim, Yun-Hae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 550~555
DOI : 10.3795/KSME-A.2007.31.5.550
The effective fracture toughness testing of materials intended for application in Micro Electro Mechanical Systems (MEMS) devices is required in order to improve understanding of how micro sized material used in device may be expected to perform upon the micro scale.
-TiAl based materials are being considered for application in MEMS devices at elevated temperatures. Especially, in Alloy 4, both
lamellae were altered markedly in 3,000 h,
exposure. Parallel decomposition of coarse
into bunches of very fine (
) lamellae. Parallel decomposition of coarse
into bunches of very fine (
) lamellae. The materials were examined 2 types Alloy 4 on heat exposed specimen(
, 3,000 h) and no heat exposed one. Micro sized cantilever beams were prepared mechanical polishing on both side at
and electro final stage polishing to observe lamellar orientation of same colony with EBSD (Electron Backscatter Diffraction Pattern). Through lamellar orientation as inter-lamellae or trans-lamellae, Cantilever beam was fabricated with Focused Ion Beam(FIB). The directional behavior of the lamellar structure was important property in single material, because of the effects of the different processing method and variations in properties according to lamellar orientation. In MEMS application, it is first necessary to have a reliable understanding of the manufacturing methods to be used to produce micro structure.
Improvement of Moldability for Ultra Thin-Wall Molding with Micro-Patterns
Yun, Jae-Ho ; Park, Keun ; Kwon, Oh-Kyung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 556~561
DOI : 10.3795/KSME-A.2007.31.5.556
The rapid thermal response(RTR) molding is a novel process developed to raise the temperature of mold surface rapidly in the injection stage and then cool rapidly to the ejection temperature by air or water. The objectives of this paper are to investigate the effect of mold temperature, pressure and thickness of micro pattern molding and to provide a optimization of RTR injection molding for micro pattern from Moldflow simulation. Optimal minimum temperature and pressure was found without shortcut according to thickness. Filling percentage was influenced by glass transition temperature with the kinds of resin. Optimal temperature is slightly higher than glass transition temperature irrespectively of pressure, thickness, the kinds of resin in the micro pattern molding.
Limit Load and Approximate J-Integral Estimates for Axial-Through Wall Cracked Pipe Bend
Song, Tae-Kwang ; Kim, Jong-Sung ; Jin, Tae-Eun ; Kim, Yun-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 562~569
DOI : 10.3795/KSME-A.2007.31.5.562
This paper presents plastic limit loads and approximate J estimates for axial through-wall cracked pipe bends under internal pressure and in-plane bending. Geometric variables associated with a crack and pipe bend are systematically varied, and three possible crack locations (intrados, extrados and crown) in pipe bends are considered. Based on small strain finite element limit analyses using elastic-perfectly plastic materials, effect of bend and crack geometries on plastic limit loads for axial through-wall cracked pipe bends under internal pressure and in-plane bending are quantified, and closed-form limit solutions are given. Based on proposed limit load solutions, a J estimation scheme for axial through-wall cracked pipe bends under internal pressure and in-plane bending is proposed based on reference stress approach.
A Study on the Performance Improvement of the Micromachined Convective Accelerometer
Youn, Sung-Kie ; Oh, Jun-Seok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 570~577
DOI : 10.3795/KSME-A.2007.31.5.570
A micromachined convective accelerometer is a recently developed device. Typical micromachined accelerometers use a solid proof mass for measuring acceleration. But a micromachined convective accelerometer does not use a solid proof mass. A micromachined convective accelerometer is composed of a heating resistor and temperature sensors. This device measures acceleration by using convective heat transfer phenomenon. Therefore characteristics of a micromachined convective accelerometer are different as compared with typical micromachined accelerometer. In this research, we analyze the convective accelerometer by using transient convective heat transfer analysis. Based on the results of a convective accelerometer, we propose a new model which has improved performance.
Dynamic Behavior of Vacuum Circuit Breaker with Permanent Magnetic Actuator
Yu, Lyun ; Kim, Young-Geun ; Lee, Sung-Ho ; Cho, Hae-Yong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 578~585
DOI : 10.3795/KSME-A.2007.31.5.578
A vacuum circuit breaker (VCB) with permanent magnet actuator (PMA) has been studied in this study. Electromagnetic field analysis and dynamic simulations have been carried out for optimal design of VCB by using commercial software Maxwell and ADAMS. This simulation model can be an effective method for the VCB, which has non-linear output force of PMA, friction, and impact for operations. An experiment has been conducted to evaluate correctness of the simulated model. By using this evaluated model, the displacement and velocity characteristics of the VCB have been simulated with following conditions : (1) The different output forces of PMA have been applied, (2) The friction conditions in follow lever shaft and moving part have been changed, (3) The mass conditions of moving part have been changed. The simulated results shows that the velocity characteristics are mainly determined by the output force of PMA. The effects due to the changes of friction conditions against the dynamic characteristics was small, and the mass conditions of the moving parts affect the velocity and a bouncing phenomenon of VCB. From these results, the optimal design conditions for the VCB have been derived.
Plastic Limit Loads of 90° Elbows with Local Wall Thinning using Small Strain FE Limit Analyses (I) - Internal Pressure -
An, Joong-Hyok ; Kim, Jong-Hyun ; Hong, Seok-Pyo ; Park, Chi-Yong ; Kim, Yun-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 586~593
DOI : 10.3795/KSME-A.2007.31.5.586
This paper proposes closed-form plastic limit load solutions for elbow with local wall thinning at extrados under internal pressure. This work was performed using 3-dimensional, small strain FE analyses based on elastic-perfectly plastic materials. The wide range of elbow and local wall thinning geometries are considered. For systematic analyses for effect of axial thinning extent on limit loads, two limiting cases are considered; a sufficiently long thinning, and the circumferential part-through surface crack. Then, the closed-form plastic limit load solutions for intermediate thinning are obtained by using result of two limiting cases. The effect of axial thinning extent for elbow on plastic limit load is highlighted by comparing with that for straight pipes. Although the proposed limit load solutions are developed for the case when local wall thinning exist in the center of elbow, it is also shown that they can be applied to the case when local wall thinning exists anywhere within elbow.
A Study on Rapid Mold Heating System using High-Frequency Induction Heating
Jeong, Hui-Tack ; Yun, Jae-Ho ; Park, Keun ; Kwon, Oh-Kyung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 594~600
DOI : 10.3795/KSME-A.2007.31.5.594
Rapid mold heating has been recent issue to enable the injection molding of thin-walled parts or micro/nano structures. Induction heating is an efficient way to heat a conductive workpiece by means of high-frequency electric current caused by electromagnetic induction. Because the induction heating is a convenient and efficient way of indirect heating, it has various applications such as heat treatment, brazing, welding, melting, and mold heating. The present study covers an experimental investigation on the rapid heating using the induction heating and rapid cooling using a vortex tube in order to eliminate an excessive cycle time increase. Experiments are performed in the case of a steel cup mold core with various heating and cooling conditions. Temperature is measured during heating and cooling time, from which appropriate mold heating and cooling conditions can be obtained.
Optimum Design of Washing Machine Flange using Design of Experiment
Lee, In-Soo ; Kim, Byung-Min ; Kim, Eui-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 601~608
DOI : 10.3795/KSME-A.2007.31.5.601
To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Flange is located between the drum and shaft, transferring power from the shaft to drum, and acting as a supporter of the back of the drum. Because section of flange has various design factors according to configuration of flange, the optimum conditions can’t be easily determined. Using a design of experiment (DOE), this study was performed investigating the interaction effect between factors as well as the main effect of the each design factor under bending and twist and proposed optimum condition using center composition method among response surface derived from regression equation of simulation-based DOE.
Development of Robot Simulator for Palletizing Operation Management S/W and Fast Algorithm for 'PLP'
Lim, Sung-Jin ; Kang, Maing-Kyu ; Han, Chang-Soo ; Song, Young-Hoon ; Kim, Sung-Rak ; Han, Jeong-Su ; Yu, Seung-Nam ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 609~616
DOI : 10.3795/KSME-A.2007.31.5.609
Palletizing is necessary to promote the efficiency of storage and shipping tasks. These are, however some of the most monotonous, heavy and laborious tasks in the factory. Therefore many types of robot palletizing systems have been developed, but many robot motion commands still depend on the teaching pendent. That is, an operator inputs the motion command lines one by one. It is very troublesome, and most of all, the user must know how to type the code. That is why we propose a new GUI (Graphic User Interface) Palletizing System. To cope with this issue, we proposed a 'PLP' (Pallet Loading Problem) algorithm, Fast Algorithm and realize 3D auto-patterning visualization interface. Finally, we propose the robot palletizing simulator. Internally, the schematic of this simulator is as follows. First, an user inputs the physical information of object. Second, simulator calculates the optimal pattern for the object and visualizes the result. Finally, the calculated position data of object is passed to the robot simulator. To develop the robot simulator, we use an articulated robot, and analyze the kinematics and dynamics. Especially, All problem including thousands of boxes were completely calculated in less than 1 second and resulted in optimal solutions by the Fast Algorithm.
Design, Simulation and Fabrication of a Quadstable Monolithic Mechanism
Han, Jeong-Sam ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 617~624
DOI : 10.3795/KSME-A.2007.31.5.617
This paper presents a novel quadstable monolithic mechanism (QsMM) which provides four stable equilibrium positions within its operation range. The quadstable mechanism has been realized from the use of both X- and Y-directional bistable structures which use curved snapping beams. A millimeter-scale brass mechanism was fabricated by ultra-precision milling to test the quadstability and the displacement-load behavior, and the prototype clearly demonstrated four distinct stable positions in its millimeter-scale planar operation. We discuss the design concept, finite element simulation for static and transient responses, fabrication by ultra-precision milling, and experimental measurement of the proposed quadstable mechanism.
Design of Gimbal Hub for Smart UAV Tilt Rotor
Lee, Joo-Young ; Kim, Jai-Moo ; Lee, Myeong-Kyu ;
Transactions of the Korean Society of Mechanical Engineers A, volume 31, issue 5, 2007, Pages 625~634
DOI : 10.3795/KSME-A.2007.31.5.625
KARI SUAV program was initiated to develop a Smart Unmanned Aerial Vehicle with innovative smart technologies. SUAV is a tilt rotor aircraft of which rotor system is 3-bladed, gimbaled hub type. Several existing concepts of gimbaled hub were analyzed and compared to investigate the applicability to SUAV rotor system design. From the result of these investigations, it was concluded that a new design concept of low cost and high reliability characteristics was necessary for the rotor hub development of SUAV. The design requirements of new gimbal hub concept and the design results were presented. Also, the analysis results to verify the satisfaction of design requirements of SUAV rotor system were presented.