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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 37, Issue 12 - Dec 2013
Volume 37, Issue 11 - Nov 2013
Volume 37, Issue 10 - Oct 2013
Volume 37, Issue 9 - Sep 2013
Volume 37, Issue 8 - Aug 2013
Volume 37, Issue 7 - Jul 2013
Volume 37, Issue 6 - Jun 2013
Volume 37, Issue 5 - May 2013
Volume 37, Issue 4 - Apr 2013
Volume 37, Issue 3 - Mar 2013
Volume 37, Issue 2 - Feb 2013
Volume 37, Issue 1 - Jan 2013
Selecting the target year
Analysis of Running Safety According to Changes of Guard Rail Length on F10/F12 Turnout
Eom, Beom Gyu ; Kim, Sung Jong ; Lee, Seung Il ; Lee, Hi Sung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 723~730
DOI : 10.3795/KSME-A.2013.37.6.723
The speed-limit regulation on a turnout is the main factor inhibiting the speed-up of conventional lines. The specified speed for a train moving through a turnout system is lower than that for a train traveling over the general track. This is done to ensure the running safety of a railway vehicle moving through a turnout. In this study, the shape change example of the guard rail component of a turnout in the Daegu Metropolitan Transit Corporation (DTRO) system was studied. A theoretical examination of the geometrical interaction formula according to wheel/rail shape at the turnout was conducted. Running safety analysis by changing the length of the guard rail on the F10/F12 turnout using the developed analysis techniques (by VI-Rail) was achieved, and the effect on railway safety was examined accordingly.
Fault-Tolerant Driving Control of Independent Steer-by-Wire System for 6WD/6WS Vehicles Using High Slip
Nah, Jae Won ; Kim, Won Gun ; Yi, Kyongsu ; Lee, Jongseok ; Lee, Daeok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 731~738
DOI : 10.3795/KSME-A.2013.37.6.731
This paper describes a fault-tolerant driving control strategy for an independent steer-by-wire system in sixwheel-drive/six-wheel-steering vehicles. An algorithm has been designed to realize vehicle maneuverability that is as close as possible to that of non-faulty vehicles by inducing high slip ratio of the wheel through a faulty steer-by-wire system in order to reduce the lateral tire force, which is resistant to the yaw motion. Considering the transition of the longitudinal tire force of a wheel with a faulty steer-by-wire component, the longitudinal tire forces are optimally distributed to the other wheels. Fault-tolerant driving performance has been investigated via computer simulations. Simulation studies show that the proposed algorithm can significantly improve the maneuverability of a vehicle with a faulty steer-by-wire system as compared to the optimal traction distribution method.
Erosion-Corrosion Behavior of Power Plant Pipe Caused by Hot Feed Water
Bang, Sung-Ho ; Lee, Jin-Won ; Kim, Tae-Won ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 739~745
DOI : 10.3795/KSME-A.2013.37.6.739
In this study, we tried to define the erosion-corrosion behavior together with the resulting effects on a pipe that is a part of a feed water circulation system according to the pipe size and hot feed water environment. An erosioncorrosion analysis was performed through the Hayduk and Minhas model based on the chemical reaction between iron and oxygen, an essential corrosive factor. The erosion-corrosion rate against the pipe diameter and feed water temperature was then evaluated by means of finite element analysis using ABAQUS. As shown in the results, the feed water temperature was the main factor influencing the erosion-corrosion rate; in particular, it was expected that the thickness of 316 stainless steel would decrease by
every year in a hot water environment at
Analysis of Durability of Vehicle Chassis Part in Virtual Test Lab
Cho, ByungKwan ; Ha, Jungho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 747~752
DOI : 10.3795/KSME-A.2013.37.6.747
Recently, virtual test laboratory techniques have been widely used to reduce vehicle development costs and time. In this study, a virtual durability test process using multibody dynamics simulation and fatigue simulation is proposed. The flexible multibody model of the front half of a car suspension is solved using road loads that are measured from durability test courses such as a Belgian road. To verify the simulation results, the measured loads of components and simulation results are collated.
Estimation of Elastic Plastic Behavior Fracture Toughness Under Hydrogen Condition of Inconel 617 from Small Punch Test
Kim, Nak Hyun ; Kim, Yun Jae ; Yoon, Kee Bong ; Ma, Young Hwa ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 753~760
DOI : 10.3795/KSME-A.2013.37.6.753
The hydrogen embrittlement of metallic materials is an important issue from the viewpoint of structural integrity. In this regard, the estimation of mechanical properties and fracture toughness under hydrogen conditions provides very important data. This study provides an experimental validation of the approach for simulating the small punch of Inconel 617 using finite element damage analysis, as recently proposed by the authors, and applies an inverse method for the determination of the constitutive tensile behavior of materials. The mechanical properties obtained from the inverse method are compared with those obtained from the tensile test and validated. The mechanical properties and fracture toughness are predicted by using the inverse method and finite element damage analysis.
Analysis of Hypervelocity Impact Fracture Behavior of Multiple Bumper Steel Plates
Jo, Jong Hyun ; Lee, Young Shin ; Kim, Jae Hoon ; Bae, Yong Woon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 761~768
DOI : 10.3795/KSME-A.2013.37.6.761
New warheads are designed and developed to be highly lethal when used as part of ballistic missile payloads. There are many trades associated with the design of a central warhead core, mainly dealing with the projectiles or penetrators. Obviously, a payload-type configuration is very susceptible to kills from one projectile because of the high impacts required for bomblet or submunition payloads. Based on these requirements, the optimum kill vehicle configuration will have the smallest mass and relative velocity that will kill all the submunitions. The designs of the penetrator shape and size are directly related to the space and weight of the warhead. The shape, size, L/D, penetrator material, and manner in which they are inserted inside the surrounding explosive segments are critical in achieving successful penetrator design. The AUTODYN-3D code was used to study the effect of penetrator penetration. The objective of numerical analysis was to determine the penetration characteristics of the penetrator produced by hypervelocity impacts under different initial conditions such as initial velocity, shape, and L/D of the penetrator.
Parametric Study of Gas Turbine Engine Disc using Axisymmetry and Sector Analysis Model
Huh, Jae Sung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 769~774
DOI : 10.3795/KSME-A.2013.37.6.769
Turbine blades and disc, which are one of the most important rotating parts of a gas turbine engine, are required to have highly efficient performance in order to minimize the total life cycle costs. Owing to these requirements, these components are exposed to severe conditions such as extreme turbine inlet temperatures, high compression ratios, and high speeds. To evaluate the structural integrity of a turbine disc under these conditions, material modeling and finite element analysis techniques are essential; furthermore, shape optimization is necessary for determining the optimal solution. This study aims to generate 2D finite element models of an axisymmetry model and a sector one and to perform thermal-structural coupled-field analysis and contact analysis. Structurally vulnerable areas such as the disc bore and disc-blade interface region are analyzed by a parametric study. Finally, an improved design is provided based on the results, and the necessity of elaborate shape optimization is confirmed.
Experimental Investigation of Fatigue Crack Growth Behavior in Friction Stir Welded 7075-T651 Aluminum Alloy Joints under Constant Stress Intensity Factor Range Control Testing (For LT Orientation Specimen)
Jeong, Yeui Han ; Kim, Seon Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 775~782
DOI : 10.3795/KSME-A.2013.37.6.775
In this study, as a series of studies aimed at investigating the spatial randomness of fatigue crack growth for friction stir welded (FSWed) 7075-T651 aluminum alloy joints, the fatigue crack growth behavior of FSWed 7075-T651 aluminum alloy joints was investigated for LT orientation specimens. Fatigue crack growth tests were conducted under constant stress intensity factor range (SIFR) control for 5 specimens of the FSWed 7075-T651 aluminum alloy, including base metal (BM), heat affected zone (HAZ), and weld metal (WM) specimens. The mean fatigue crack growth rate of WM specimens was found to be the highest, whereas that of HAZ and WM specimens was the lowest. Furthermore, the variability of fatigue crack growth rate was found to be the highest in WM specimens and lowest in BM specimens.
Circular Path Generation Technique for Ball Bar Measurement by Simultaneous Movement of Two Axes
Lee, Dong-Mok ; Lee, Hoon-Hee ; Yang, Seung-Han ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 783~790
DOI : 10.3795/KSME-A.2013.37.6.783
Circular path generation for ball bar measurement using the simultaneous movement of two axes with at least one rotary axis requires the execution of CAM software. However, a change in the machine type or measurement condition requires a new execution of the CAM software, which is cumbersome. This paper presents a circular path generation technique that does not require CAM software and is applicable to different types of driving axes with an arbitrary structural configuration of machine tools and any ball bar setup condition. Mathematical equations are derived for three cases using the proposed technique. In addition, to inspect the measurement feasibility for avoiding physical interference among the ball bar parts, a tilting angle calculation is proposed. The validity of the proposed technique was verified by performing a ball bar experiment with A and C as the simultaneous axes of a five-axis machine tool.
Evaluation of Mechanical Property of Carbon Fiber/Polypropylene Composite According to Carbon Fiber Surface Treatment
Han, Song Hee ; Oh, Hyun Ju ; Kim, Seong Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 791~796
DOI : 10.3795/KSME-A.2013.37.6.791
In this study, the mechanical properties of a carbon fiber/polypropylene composite were evaluated according to the carbon fiber surface treatment. Carbon fiber surface treatments such as silane coupling agents and plasma treatment were performed to enhance the interfacial strength between carbon fibers and polypropylene. The treated carbon fiber surface was characterized by XPS, SEM, and single-filament tensile test. The interlaminar shear strength (ILSS) of the composite with respect to the surface treatment was determined by a short beam shear test. The test results showed that the ILSS of the plasma-treated specimen increased with the treatment time. The ILSS of the specimen treated with a silane coupling agent after plasma treatment increased by 48.7% compared to that of the untreated specimen.
Development of Moving Average Prediction Diagnostic Module for Vibration Parameter Influenced by Environmental Factors
Oh, Se-Do ; Kim, Young-Jin ; Lee, Tae-Hwi ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 797~804
DOI : 10.3795/KSME-A.2013.37.6.797
In this study, the authors develop a methodology for a diagnostic system with a vibration parameter that is influenced by environmental factors. The data tends to have a varying average over time. Often, these features are found in statistical data retrieved from a production line. If we utilize existing statistical techniques for these features, we could derive an incorrect diagnostic conclusion based on the different average values. To overcome the limitations of previous methods, the authors apply a function analyzed through regression analysis to predict the mean value and corresponding upper and lower limits at each stage. This technique also provides corresponding statistical parameters in varying dynamic means. To validate the proposed methods, we retrieve data from the engine assembly line of H Motors and verify the results.
Robust Controller Design for Hydraulic Dipod Platform Based on 2-DOF H
Controller Synthesis Framework
Lee, Young-Hoon ; Cho, Taik-Dong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 805~814
DOI : 10.3795/KSME-A.2013.37.6.805
A hydraulic dipod platform is used for tracking and stabilizing an antenna system to designate a satellite on a moving vehicle. The 2-DOF controller is very well suited to this controller design object because it is more flexible than the 1-DOF controller when the design object is not only the consideration between stabilizing and tracking but also the trade-off between performance and robustness. The 2-DOF controller synthesis based on the
framework is divided into two design procedures. In this hydraulic dipod platform example, the single-step method shows better performance whereas the two-step method shows better robustness. The difference between these two synthesis results is compared using the structural property of the interconnection system matrix.
Study of Automatic Cleaning Tool Designs for Exterior Wall of Buildings
Lee, Jin Koo ; Kim, Dae Myoung ; Lee, Dong Ju ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 815~820
DOI : 10.3795/KSME-A.2013.37.6.815
With the development of technology, there has been a considerable increase in the number of skyscrapers in the world. Accordingly, there are increasing requirements with regard to maintenance, such as cleaning, painting, and inspection. However, it is extremely dangerous to work on the walls of buildings, and falls from buildings have accounted for a large proportion of construction accidents. In particular, as the number of buildings with irregular shapes increases, the accident rate during maintenance work has increased each year, with most accidents leading to deaths. An alternative solution must be developed with the commercialization of automatic systems. In this study, fundamental research has been conducted for drafting and commercializing an automation tool with a built-in guide system that can perform cleaning.
RBDO of Coil Spring Considering Transversal Direction Mode Tracking
Lee, Jin Min ; Jang, Junyong ; Lee, Tae Hee ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 821~826
DOI : 10.3795/KSME-A.2013.37.6.821
When the values of design variables change, mode switching can often occur. If the mode of interest is not tracked, the frequencies and modes for design optimization may be miscalculated owing to modes that differ from the intended ones. Thus, mode tracking must be employed to identify the frequencies and modes of interest whenever the values of design variables change during optimization. Furthermore, reliability-based design optimization (RBDO) must be performed for design problems with design variables containing uncertainty. In this research, we perform RBDO considering the mode tracking of a compressive coil spring, i.e., a component of the joint spring that supports a compressor, with design variables containing uncertainty by using only kriging metamodels based on multiple responses approach (MRA) without existing mode tracking methods. The reliability analyses for RBDO are employed using kriging metamodel-based Monte Carlo simulation.
Evaluation of Curving Performance and Running Safety of New High-Power Electric Locomotive
Ham, Young Sam ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 6, 2013, Pages 827~832
DOI : 10.3795/KSME-A.2013.37.6.827
In this study, curve responsiveness was assessed based on the lateral force and running safety was evaluated based on the wheel unloading ratio and derailment coefficient, which is the ratio of the wheel load and the lateral force. The evaluation of the curving performance and running safety of the new high-power electric locomotive showed that the derailment coefficient appeared higher when the wheel-set was set to the front of the train instead of being placed backward, and the maximum value of the derailment coefficient was recorded as 0.572 on the Gyeongbu line. Furthermore, the lateral force increased in curved sections, and it appeared to be proportional to the curve radius. Meanwhile, a maximum axis lateral force of 77.6 kN was recorded on the Taebaek line, and the wheel unloading ratio was 47.6% on the Yeongdong line. Finally, the running safety at the maximum speed as well as the through-curve performance of the curve radius satisfied the required standards.