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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
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Journal DOI :
The Korean Society of Mechanical Engineers
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Volume & Issues
Volume 35, Issue 12 - Dec 2011
Volume 35, Issue 11 - Nov 2011
Volume 35, Issue 10 - Oct 2011
Volume 35, Issue 9 - Sep 2011
Volume 35, Issue 8 - Aug 2011
Volume 35, Issue 7 - Jul 2011
Volume 35, Issue 6 - Jun 2011
Volume 35, Issue 5 - May 2011
Volume 35, Issue 4 - Apr 2011
Volume 35, Issue 3 - Mar 2011
Volume 35, Issue 2 - Feb 2011
Volume 35, Issue 1 - Jan 2011
Selecting the target year
Study on Effect of Mechanical Machining and Heat Treatment on Surface Residual Stress of TP316L Stainless Steel
Lee, Kyoung-Soo ; Lee, Jeong-Keun ; Song, Ki-O ; Park, Jai-Hak ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 453~458
DOI : 10.3795/KSME-A.2011.35.5.453
We study the effect of mechanical machining and heat treatment on the surface residual stress of TP 316L stainless steel. Electrical discharge machining (EDM), milling and grinding were applied to TP 316L plate specimens. The residual stress and hardness were measured and the effect of heat treatment on the surface residual stress was examined. The residual stress was measured by the X-ray diffraction method, which showed that the surface residual stress was related only to the stress magnitude and was independent of the compressive or tensile component. The surface residual stress was greatly decreased by the heat treatment, but it was not removed completely.
Basic Experiment on Rehabilitation of Upper-Limb Motor Function Using Haptic-Device System
Lee, Ho-Kyoo ; Kim, Young-Tark ; Takahashi, Yoshiyuki ; Miyoshi, Tasuku ; Suzuki, Keisuke ; Komeda, Takashi ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 459~467
DOI : 10.3795/KSME-A.2011.35.5.459
Rehabilitation exercises must maintain a patient`s interest and permit a quantitative evaluation of the rehabilitation. We have developed a haptic-device system. When users move a grip, the haptic device provides a virtual force that either assists the movement of their arm or working against it. To investigate the functional effect of this system in a rehabilitation program, we used for five subjects with motor-function disorders and measured the grip position, velocity, force exerted on the grip, and EMG activities during a reaching task of one subject. The accuracy of the grip position, velocity and trajectories patterns were similar for all the subjects. The results suggested that the EMG activities were improved by applying the virtual force to the grip. These results can be used for the development of rehabilitation programs and evaluation methods.
Development of Product Management System for Higher-Value-Added Bicycle
Lee, Philippe ; Hwang, In-Hyuck ; Woo, Jong-Hun ; Park, Se-Won ; Oh, Dae-Kyun ; Lee, Gyu-Bong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 469~477
DOI : 10.3795/KSME-A.2011.35.5.469
Nowadays, environmentally friendly technology is attracting considerable attention because of environmental pollution and the increasing price of raw materials. Korea has a high level of dependence on exports, and therefore it has stressed the development of environmentally friendly technologies. Bicycle manufacturing industry has a bright future because bicycles do not use fossil fuels, and cycling is good for one`s health. We develop a management system for the effective development of next-generation environmentally friendly technology for bicycles. The goal is to promote the bicycle industry in Korea while keeping the product in the low to medium price range.
Study on Real-Time Digital Filter Design as Function of Scanning Frequency of Focused Electron Beam
Kim, Seung-Jae ; Oh, Se-Kyu ; Yang, Kyung-Sun ; Jung, Kwang-Oh ; Kim, Dong-Hwan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 479~485
DOI : 10.3795/KSME-A.2011.35.5.479
To acquire images in a thermionic-scanning electron-beam system, a scanning unit is needed to control the electron beam emitted from the tungsten filament source. In scanning the electron beam on the solid surface, the signalto-noise ratio depends on the scanning frequency. We used a digital filter to reduce noise by analyzing the real-time frequency of a secondary electron signal. The noise and the true image signal were well separated. We designed the digital filter via a DSP floating-point operation, and the noise elimination resulted in enhanced image quality in a highresolution mode.
Study on Flow Characteristics and Discharge Coefficient of Safety Valve for LNG/LNG-FPSO Ships
Kim, Sung-Jin ; Jung, Sung-Yuen ; Kim, Dang-Ju ; Kim, Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 487~494
DOI : 10.3795/KSME-A.2011.35.5.487
The safety valve used in LNG/LNG-FPSO ships plays an important role in maintaining a fixed level of pressure by emitting LNG gas out of the pipes in the LNG piping system. The discharge coefficient is regarded as the most important factor in the valve performance. To satisfy the ship`s classification, the discharge coefficient of the safety valve must usually be over 0.8. Despite the importance of understanding the flow phenomena inside the safety valve, the valve design is usually based on experience and experiments. We carried out a computational fluid dynamics (CFD) investigation using the ANSYS-CFX software. We observed the flow phenomena inside the valve and measured the discharge coefficients according to changes in the valve lift, which is the distance between the exit of the nozzle and the lower part of the disc plate. We verified our CFD results for the discharge coefficients using available experimental data.
Experimental Study on Electrical Discharge in Nanoscale Gaps
Lee, Young-Min ; Choi, Hae-Woon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 495~501
DOI : 10.3795/KSME-A.2011.35.5.495
We present an experimental study of electrical discharge in nanoscale gaps. The discharge occurred between a cathode made of sharpened Pt-Ir wire and a gold-plated anode. Electric discharges were detected for electric potentials from 10 V to 80 V, and their gaps ranged from 50 nm to 800 nm. The spark signals indirectly showed spark phenomena such as discharges or shortages in the system. The sparks and discharges strongly depended on the electric potential (voltage) and the radius of the tips. For small gaps, the electrical discharge was random and strongly depended on the radius of the cathode tips.
Kinematic Characteristics of Walking-Assistance Robot
Bae, Ha-Suk ; Kim, Jin-Oh ; Chun, Han-Yong ; Park, Kwang-Hun ; Lee, Kyung-Whan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 503~515
DOI : 10.3795/KSME-A.2011.35.5.503
We developed a walking-assistance robot for walking rehabilitation and assessed the kinematic characteristics of a prototype. The walking-assistance robot is composed of hip, knee, and ankle joints, and each joint is driven by a motor with a decelerator. The equations of angular displacement while walking were derived by theoretically analyzing human locomotion, and the calculated angular displacements were then applied to the robot controller. The output angular displacement of each joint was measured and compared with its input angular displacement in walking experiments on a treadmill at various walking speeds and strides. The differences between the input and output angular displacements are 5.22% for the hip and 2.97% for the knee joints, and it has been confirmed that the walking-assistance robot works well.
Effect of Lateral and Posterior Placement of Single-Bundle and Double-Bundle ACL Reconstructions on Tibial Internal Rotation During Single-Leg Landing
Shin, Choong-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 517~523
DOI : 10.3795/KSME-A.2011.35.5.517
Anterior cruciate ligament (ACL) injuries are treatedwith surgical reconstruction. Although ACL consists of two functional bundles, only the anteromedial bundle is surgically reconstructed, and the effect of the reconstruction of the posterolateral bundle is unknown. The purpose of this study is to investigate the role of the posterolateral bundle and the effect of double-bundle reconstruction during single-leg landing. A 3D dynamic knee with various ACL reconstructed models was created using MRI, and single-leg landing motion was simulated using in-vivo human experimental data. The results showed that the lateral shift of the tibial insertion of the anteromedial bundle and the posterolateral bundle of the ACL constrain the tibial internal rotation more efficiently than a single anteromedial bundle can. In addition, double-bundle ACL reconstruction is less sensitive to inaccuracies in the tibial tunnel placement.
Study of Road Load of Electric Two-Wheeled Vehicle
Kil, Bum-Soo ; Kim, Gang-Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 525~531
DOI : 10.3795/KSME-A.2011.35.5.525
Recently, the demand of environmentally friendly transportation has increased due to the environmental issues. Electric two-wheeled vehicles do not have the noise pollution nor exhaust gases of vehicles with internal combustion engines. Performance evaluation of an electric two-wheeled vehicle was carried out. A driving test on outdoor roads was performed and a chassis dynamometer was used. The chassis dynamometer simulates the road load of the vehicle. The road load influences the tests using the chassis dynamometer. The differences between the table method and the coasting test for setting the road load was compared and analyzed.
Model Estimation and Precise Position Control of an Antagonistic Actuation with Pneumatic Artificial Muscles
Kang, Bong-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 533~541
DOI : 10.3795/KSME-A.2011.35.5.533
This paper presents a frequency-response test performed on an antagonistic actuation system consisting of two Mckibben pneumatic artificial muscles and a pneumatic circuit with pressure valves. Varying switching frequency to pressure valves from 0.1 Hz to 5 Hz, parameters of a linear model were estimated optimally to predict dynamic characteristics of the antagonistic actuation. A model-base control scheme with estimated parameters was built for the precise trajectory tracking of the antagonistic structure and realized on a reconfigurable embedded control system, CompactRIO. Experimental results showed that the proposed model-based control scheme gave good performance in trajectory tracking comparing with a PD control scheme when square wave and sinusoidal wave were given as references to follow.
Effects on Machining on Surface Residual Stress of SA 508 and Austenitic Stainless Steel
Lee, Kyoung-Soo ; Lee, Seong-Ho ; Park, Chi-Yong ; Yang, Jun-Seok ; Lee, Jeong-Geun ; Park, Jai-Hak ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 543~547
DOI : 10.3795/KSME-A.2011.35.5.543
Primary water stress corrosion cracking has occurred in dissimilar weld areas in nuclear power plants. Residual stress is a driving force in the crack. Residual stress may be generated by weld or surface machining. Residual stress due to surface machining depends on the machining method, e.g., milling, grinding, or EDM. The stress is usually distributed on or near the surface of the material. We present the measured residual stress for machining on SA 508 and austenitic stainless steels such as TP304 and F316. The residual stress can be tensile or compressive depending on the machining method. The depth and the magnitude of the residual stress depend on the material and the machining method.
Analysis of Degradation Mechanism for Single Crystal Blade and Vane in Gas Turbine
Song, Kyu-So ; Kim, Doo-Soo ; Lee, Han-Sang ; Yoo, Keun-Bong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 549~554
DOI : 10.3795/KSME-A.2011.35.5.549
Recently, technical advances have been made in high efficiency gas turbine power plants. In domestic gas turbine facilities, the material properties of the blade and vane are degraded by the daily start-stop operations arising from the thermo mechanical cycle. We surveyed the time dependent degradation of the HP blade and vane to gather basic data for life assessment and damage analysis. The EOH(equivalent operating hours) of the blades were 23,686, 27,909, and 52,859 and the EOH of the vanes were 28,714 and 52,859, respectively. With increased operating hours, the shape of the primary
` precipitate transformed from cubic to spherical, and its average size also increased. The leading edge area of the blades and the center of the vanes had the worst morphology, and this tendency agrees with the microhardness results. The thickness of the thermally grown oxide at the outer surface of the bond coat increased with increased operating hours.
Study on Fatigue Property of Material for Oil Hydraulic Piston Pump
Kim, Nam-Seok ; Nam, Ki-Woo ; Kim, Hyun-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 555~559
DOI : 10.3795/KSME-A.2011.35.5.555
Oil hydraulic piston pumps are extensively used worldwide because of their simple design, light weight, and cost effectiveness. However, an oil hydraulic pump is likely to have high leakage, friction, and low energy efficiency after long-term use. In oil hydraulic piston pumps the clearance between the valve block and the piston plays an important role in the volumetric and overall efficiency. We studied the wear property of the SACM645 material used in hydraulic piston pumps via experiments with different heat treatments. We prepared three different specimens. The maximum tensile strengths of the QT and QT-nitration specimens are similar (about 820 MPa), but the strains are significantly different. However, the fatigue characteristic depended on the heat treatment.
The Study of Simulation Dynamic Behavior of CFRP Structural Members
Kim, Jung-Ho ; Bang, Jung-Min ; Kim, Ji-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 561~565
DOI : 10.3795/KSME-A.2011.35.5.561
The structural vehicles are steel members of square or circle tube with definite shape. These members support various components and absorb impact energy to protect passengers during accidentswhen crash happen. Structural members need to be lightweight and stable. In this study, we do an impact simulation of a CFRP square member using finite element analysis program Ls-Dyna in order to predict fracture shape and energy absorb feature of CFRP member. Also, we make square member shape of CFRP and do an impact experiment. We compare the analytical and experimental results and consider the fracture shape and energy features of CFRP members.
Sound-Insulation Design of Aluminum Extruded Panel in Next-Generation High-Speed Train
Kim, Seock-Hyun ; Seo, Tae-Gun ; Kim, Jeong-Tae ; Song, Dal-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 567~574
DOI : 10.3795/KSME-A.2011.35.5.567
Aluminum extruded panels are widely used instead of corrugated steel panels for weight reduction in high-speed trains. Of the layers in the train body, it makes the largest contribution to the sound insulation. However, compared with that of a flat panel with the same weight, the TL of the aluminum extruded panel is remarkably lower in the local resonance frequency band. We study aluminum extruded panels for next-generation 400-km/h trains. We investigate the problem of sound insulation and propose a practical method to improve the sound-insulation performance. The local resonance frequency region is increased by a modification of the core structure, and urethane foam is placed in the core. The effect on the sound insulation is verified by experiments. Finally, the improvement for the entire sound-transmission loss is estimated for the layered floor panels of express trains.
Design Optimization of Cleaning Blade for Minimizing Stress
Park, Chang-Hyun ; Lee, Jun-Hee ; Choi, Dong-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 5, 2011, Pages 575~582
DOI : 10.3795/KSME-A.2011.35.5.575
A cleaning blade is an attachment installed in the toner cartridge of a laser printer for removing the residual toner from an organic photo-conductive drum. There have been many studies on the performance and life of the rubber blade. We focus on optimally designing the blade shape parameters to minimize the maximum stress of the blade while satisfying design constraints on the cleaning performance and part interference. The blade is optimally designed using a design of experiments, meta-models and an optimization algorithm implemented in PIAnO (process integration, automation, and optimization), a commercial PIDO (process integration and design optimization) tool. We integrate the CAE tools necessary for the structural analysis of the cleaning blade, automate the analysis procedure, and optimize the solution using PIAnO. We decreased the maximum stress by 32.6% in comparison with that of the initial design.