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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
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Statistical Analysis for Thickness and Surface Roughness of Printed Pattern in Roll-to-Roll Printed Electronics System
Lee, Chang Woo ; Kim, Nam Seok ; Kim, Chang Wan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 287~294
DOI : 10.3795/KSME-A.2013.37.3.287
The roll-to-roll (R2R) printed electronics system is one of the most promising technologies for the printed electronics industry because of several advantages in terms of productivity and cost. In the R2R printed electronics system, the characteristics of the printed patterns are an important issue that determines the functional quality of the printed matter. This study analyzed how several main factors may affect the characteristics of printed patterns, especially the thickness and surface roughness. The statistical model for estimation of the printed pattern was developed as a function of the main factors using the design of experiment (DOE) methodology. Based on the statistical analysis results, the R2R printed electronics system can be designed to control the characteristics of printed patterns.
Dimensional Change in Drawn Wire Product in the Two Cross-Roll Straightening Process
Moon, Changsun ; Kim, Naksoo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 295~302
DOI : 10.3795/KSME-A.2013.37.3.295
The two cross-roll straightening process at room temperature is a manufacturing method for improving the straightness of a drawn wire. The distribution and magnitude of the internal and surface residual stresses of the drawn wire are changed after the wire-drawing process through the two cross-rolls; this also results in a change in the diameter of the drawn wire. The remaining residual stresses of the drawn wire after the wire-drawing dimensional changes were analyzed according to the distance between the rolls, oblique angle between the axes of the roll and the wire, predicted residual stresses, and dimensional change in the final product. The oblique angle between the concave and convex rolls did not affect the residual stresses or dimensional change, but the distance between rolls did.
Dynamic Analysis of Driving Mechanism for Displacement Controlled Automatic Drug Injector
Shin, Young Kyu ; Han, Nam Gyu ; Tak, Tae Oh ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 303~311
DOI : 10.3795/KSME-A.2013.37.3.303
This research deals with the analysis and design of a driving mechanism for an automatic pneumatic drug injector, which can precisely control the injection volume using a relatively simple friction-driven mechanism, without any complicated control system. Through a dynamic analysis, the effects of the design parameters of the driving mechanism associated with the geometry, spring stiffness, and fiction are analyzed, and the results are reflected in a proto-type drug injector design, which is under development for mass production. A test is performed to assess the durability of the mechanism for up to one million operations, and comparison of its displacement after one million operations, verifies the mechanism's durability.
Characteristic of EP-MAP for Deburring of Microgroove using EP-MAP
Kim, Sang Oh ; Son, Chul Bae ; Kwak, Jae Seob ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 313~318
DOI : 10.3795/KSME-A.2013.37.3.313
Magnetic abrasive polishing is an advanced deburring process for nonmagnetic materials and micropattern products that have non-machinability characteristics. Despite these advantages, there are some problems with using MAP for deburring. MAP has introduced geometric errors into microgrooves because of an over-cutting force caused by uncontrolled magnetic abrasives in the MAP tool. Thus, in this study, to solve this problem, an EP (electrolyte polishing)-MAP hybrid polishing process was developed for deburring microgrooves in an STS316 material. In addition, an evaluation of EP-MAP for the deburring of microgrooves was carried out by profiling the burrs. The results of the experiment showed geometric errors after the deburring process using MAP. However, in the case of EP-MAP, no geometric error was observed after the process because of the lower material removal rate in EP-MAP.
Study on Characteristics of EP-MAP Hybrid Machining by Optimization of Magnetic Flux Density
Park, Chang Geun ; Kwak, Jae Seob ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 319~324
DOI : 10.3795/KSME-A.2013.37.3.319
In this study, an EP (electro-polishing)-MAP (magnetic abrasive polishing) hybrid process was developed as a precision finishing process. To evaluate the characteristics of this EP-MAP hybrid process, a series of experiments were carried out using various working gaps, current densities, and electrolyte concentrations. As a result,
was found to be very suitable as the electrolyte of the hybrid process because there was no electrochemical reaction with the CNT-Co composite. Moreover, an increase in the magnetic flux density affected the liquidity of the electrolyte and prevented it from flowing into the CNT-Co composite powder. For that reason, the lower liquidity of the electrolyte increased the thermal energy on the surface of the workpiece.
Low Frequency Squeal Noise Reduction using Mode Participation Factor in Complex Eigenvalue Analysis
Park, Jeong Min ; Kim, Hyun Soo ; Yoon, Moon Young ; Boo, Kwang Seok ; Kim, Heung Seob ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 325~331
DOI : 10.3795/KSME-A.2013.37.3.325
In this study, a complex eigenvalue analysis is implemented to verify the unstable mode of a brake system using ABAQUS software. The component participation factors and component modal participation factors are used to analyze the total contributions from each component and each component mode to a particular unstable system mode. This study shows that the 1.4-kHz unstable system mode comes from mode coupling between the 2nd nodal diametric mode and 3rd lateral axial mode (LAM) in the baseline model. A sensitivity analysis with a linking index is performed to prevent the mode coupling of the component modes. This linking index analysis shows the optimum mass loading position to move away the natural frequency of the 3rd LAM, which contributes to the unstable mode. Finally, a complex eigenvalue analysis is implemented with mass loading in the tie bar position, and no unstable system mode is generated in the low-frequency range (below 2 kHz).
Fatigue Characteristics and Compressive Residual Stress of Shot Peened Alloy 600 Under High Temperature
Kim, Jong Cheon ; Cho, Hong Seok ; Cheong, Seong Kyun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 333~338
DOI : 10.3795/KSME-A.2013.37.3.333
The compressive residual stress and fatigue behavior of shot peened alloy 600 under a high-temperature environment is investigated in this study. Alloy 600 is used in the main parts of nuclear power plants, and the compressive residual stress induced by the shot peening process is considered to prevent SCC (stress corrosion cracking). To obtain practical results, the fatigue characteristics and compressive residual stress are evaluated under the actual operating temperature of a domestic nuclear power plant, as well as a high-temperature environment. The experimental results show that the peening effects are valid at a high temperature lower than approximately
, which is the threshold temperature. The fatigue life was maintained at temperatures lower than
, and the compressive residual stress at
was 68.2% of that at room temperature. The present results are expected to be used to obtain basic safety and reliability data.
Study on Fatigue Characteristic of Suspension Part Using Hot Forming
Suh, Chang Hee ; Park, Myung Kyu ; Park, Jong Kyu ; Kim, Young Suk ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 339~344
DOI : 10.3795/KSME-A.2013.37.3.339
Hot forming using boron steel is currently used for manufacturing low-weight automobile body parts, and a high tensile strength of about 1,500 MPa is obtained after hot forming. However, a high fatigue life is a more important factor than high strength when it is used for automobile suspension parts. A tubular torsion beam axle (TTBA) is one of these suspension parts, and this research deals with the fatigue characteristic of TTBA using hot forming. The low cyclic fatigue life of boron steel is investigated according to the cooling method. In addition, a structural and fatigue analysis of TTBA is performed to predict the fatigue life. The stress concentration that occurs in the tubular torsion beam is found, and the longest fatigue life occurs when rapid cooling is utilized in the TTBA fabrication.
Influence of Stress Shape Function on Analysis of Contact Problem Using Hybrid Photoelasticity
Shin, Dong-Chul ; Hawong, Jai-Sug ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 345~352
DOI : 10.3795/KSME-A.2013.37.3.345
In this research, a study on stress shape functions was conducted to analyze the contact stress problem by using a hybrid photoelasticity. Because the contact stress problem is generally solved as a half-plane problem, the relationship between two analytical stress functions, which are compositions of the Airy stress function, was similar to one of the crack problem. However, this relationship in itself could not be used to solve the contact stress problem (especially one with singular points). Therefore, to analyze the contact stress problem more correctly, stress shape functions based on the condition of two contact end points had to be considered in the form of these two analytical stress functions. The four types of stress shape functions were related to the stress singularities at the two contact end points. Among them, the primary two types used for the analysis of an O-ring were selected, and their validities were verified in this work.
Change in Ultrasonic Characteristics with Isothermal Heat Treatment of 2.25Cr-1Mo Steel
Nam, Young-Hyun ; Baek, Un-Bong ; Park, Jong-Seo ; Nahm, Seung-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 353~358
DOI : 10.3795/KSME-A.2013.37.3.353
The ultrasonic characteristics of 2.25Cr-1Mo steel were investigated in relation to the isothermal heat treatment temperature and time. Charpy impact tests and hardness tests were conducted on individual specimens with three different heat treatment conditions. A pulse-echo method with longitudinal waves was used to measure the attenuation and velocity of ultrasonic waves. The FATT (fracture appearance transition temperature) increased with an increase in the isothermal heat treatment time, which implies that the toughness decreased. As the isothermal heat treatment time and temperature increased, the longitudinal wave velocity and ultrasonic attenuation coefficient were raised.
Design and Analysis of Linear Vibration Motor Equipped with Permanent-Magnet Springs and Voice-Coil Actuators
Choi, Jung-Kyu ; Yoo, Seong-Yeol ; Noh, Myounggyu ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 359~364
DOI : 10.3795/KSME-A.2013.37.3.359
In order to use a linear vibration motor for the actuator of a haptic interface, the motor must provide a higher reaction rate and longer service life than typical rotational motors with an eccentric mass. In this paper, we propose a linear vibration motor that is equipped with a voice-coil actuator and permanent-magnet springs. To concentrate the magnetic flux in the actuator, a Halbach-style magnetization pattern is used. Permanent-magnet springs replace mechanical springs to help increase the service life. We use the method of equivalent current sheets and the method of images to analyze and model the proposed vibration motor. These methods are validated using finite element analyses and experiments. A prototype motor is designed and fabricated. Tests with the prototype show the feasibility of the proposed linear vibration motor.
Statistical Analysis for Fatigue Life Evaluation of Vehicle Muffler
Choi, Ji-Hun ; Lee, Yong-Jun ; Yoon, Jin-Ho ; Kang, Sung-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 365~372
DOI : 10.3795/KSME-A.2013.37.3.365
In this study, a statistical method for evaluating the fatigue life of a vehicle muffler was used to obtain reliable fatigue data using a limited number of specimens. Cyclic bending tests were conducted using specimens manufactured to be exactly the same as the mufflers installed in cars that are currently in use. To estimate the fatigue life by comparing the data obtained during the fatigue tests, the most suitable probability density function for the normal, lognormal, and Weibull distributions was selected. A goodness-of-fit test was performed on the probability distributions, and then a Weibull distribution using the least square method was selected. By using the selected Weibull distribution, the probability-moment-life curves (P-M-N curve) reflecting the fatigue characteristics were suggested as the data for the reliable design of a muffler.
Study on Friction Characteristic of Sintered Friction Component for Synchronizer-Ring of Diesel Vehicle
Song, Joon Hyuk ; Kim, Eun Sung ; Kim, Kyung-Jae ; Oh, Je-Ha ; Yang, Sung Mo ; Kang, Shin Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 373~378
DOI : 10.3795/KSME-A.2013.37.3.373
The speed change performance of transmissions has become a serious issue because of the increase in the inertia moment that has accompanied increases in engine output and transmission size. Therefore, it is necessary to develop better wear resistant friction materials. In this study, an appropriate sintered friction component for the synchronizer ring of a diesel manual transmission was developed, and its bonding characteristics were analyzed. That is, a process for bonding an Fe-based base material and Cu-based sintered friction material was developed. BSE and EDX analyses of this bonding layer were conducted, along with a shear strength test, to determine the bonding characteristics.
Steering System Design of Commercial Vehicle for Improving Pulling Phenomenon During Braking
Lee, Chang Hun ; Lee, Dong Wook ; Lee, Yong Su ; Sohn, Jeong Hyun ; Kim, Kwang Suk ; Yoo, Wan Suk ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 379~385
DOI : 10.3795/KSME-A.2013.37.3.379
The tires, suspension type, and steering system can all cause pulling during braking. Among these, a drag link steering system and leaf-type suspension system are significant causes of vehicle pulling. In this study, the pulling problem is analyzed using the vehicle analysis program "ADAMS/CAR." The drag link and leaf spring behavior is analyzed to find the key reason for pulling. After this, the optimization program "Visual DOC" is used with "ADAMS/CAR" to find a steering link connection point to reduce pulling. After conducting this simulation, K&C (kinematic & compliance) test simulation with a modified connection point is conducted to determine whether the vehicle performance improves. Through a full braking simulation, it is verified that the pulling distance is reduced at braking.
Sensitivity Analysis of Nozzle Geometry Variables for Estimating Residual Stress in RPV CRDM Penetration Nozzle
Bae, Hong Yeol ; Oh, Chang Young ; Kim, Yun Jae ; Kim, Kwon Hee ; Chae, Soo Won ; Kim, Ju Hee ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 387~395
DOI : 10.3795/KSME-A.2013.37.3.387
Recently, several circumferential cracks were found in the control rod drive mechanism (CRDM) nozzles of U.S. nuclear power plants. According to the accident analyses, coolant leaks were caused by primary water stress corrosion cracking (PWSCC). The tensile residual stresses caused by welding, corrosion sensitive materials, and boric acid solution cause PWSCC. Therefore, an exact estimation of the residual stress is important for reliable operation. In this study, finite element simulations were conducted to investigate the effects of the tube geometry (thickness and radius) on the residual stresses in a J-groove weld for different CRDM tube locations. Two different tube locations were considered (center-hole and steepest side hill tube), and the tube radius and thickness variables (
=2, 3, 4) included two different reference values (
Optimization of Battery Power Distribution to Improve Fuel Consumption of Fuel Cell Hybrid Vehicle
Lee, Dong Sup ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 397~403
DOI : 10.3795/KSME-A.2013.37.3.397
The demand for eco-friendly and higher fuel economy vehicles has helped develop eco-friendly and fuel-efficient vehicles such as hybrid vehicles. In a hybrid vehicle, the change in the battery charge after driving should be added to the fuel consumption as the equivalent fuel usage based on its own characteristics. Thus, the fuel efficiency of a hybrid vehicle cannot be improved simply by increasing the battery capacity. In this study, I attempt to improve the total fuel economy of a hybrid vehicle, including the equivalent fuel consumption, by modeling a fuel cell hybrid vehicle using Matlab Simulink, analyzing the usage zone of the fuel cell with the existing control strategy, and optimizing the power distribution of the battery and fuel cell in the main usage zone of the fuel cell.
Prediction of Steady-State Stresses within Heat Affected Zone Due to Creep Mismatch in Welded Straight Pipes
Han, Jae-Jun ; Kim, Sang-Hyun ; Chung, Jin-Taek ; Kim, Yun-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 405~412
DOI : 10.3795/KSME-A.2013.37.3.405
This paper reports the steady-state stresses within the heat affected zone (HAZ) of a welded straight pipe subject to creep. The creep constants and exponent are varied systematically to see the effect of various mismatches in creep properties on the steady-state creep stresses, via detailed two-dimensional finite element (FE) creep analyses. The weldments consist of the base metal and weld metal with the HAZ, which are characterized using the idealized power creep laws with the same creep exponent. The internal pressure and axial loading are considered to see the effect of the loading mode. To quantify the creep stresses, a creep mismatch factor is introduced as a function of the creep constants and exponent. It is concluded that the ratio of the section-averaged stresses for a mismatched case to those for an evenmatched case are linearly dependent on the mismatch factor. The results are compared with the FE results, including the Type IV region, as well as the R5 procedure.
Vibration Pattern Design Method for Improving Tactile Sensibility
Kim, Sungmin ; Lee, Soo-Hong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 413~418
DOI : 10.3795/KSME-A.2013.37.3.413
As haptic devices become increasingly important in various product fields, it becomes essential to design effective vibration patterns for better tactile sensitivities. Despite this trend, standardization in the design of vibration patterns has not been well established, which causes developers to neglect the effects of haptics while programming or developing products. To provide better tactile sensitivity, the present study introduces a vibration pattern design system and proposes guidelines for designing vibration patterns. This system consists of two modules: (1) a graphical pattern design and evaluation program and (2) a vibro-tactile display device for prototyping the designed vibration patterns.
Development of Program for Predicting GBD to Improve Canning Process Capability for Catalytic Converter
Lee, Young Dae ; Chu, Seok Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 419~427
DOI : 10.3795/KSME-A.2013.37.3.419
The catalytic converters for automobile exhaust systems are manufactured by inserting a mat-wrapped substrate into a stainless steel can. A residual pressure that is too high will initiate a fracture in the substrate. In contrast, a residual pressure that is too low will fail to hold the substrate in the acceleration or deceleration phase. Both the process capability and mat pressure on the substrate are predicted while considering the effect of the statistical variation in the dimensions of the parts. The validity of the solutions is then confirmed. A program using EXCEL combines a finite element analysis and process capability analysis in one program.
Probabilistic Analysis of Fatigue Behavior of Induction Hardened Steel
Lee, Seon-Ho ; Lee, Seung-Pyo ; Kang, Ki Weon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 3, 2013, Pages 429~436
DOI : 10.3795/KSME-A.2013.37.3.429
This study considers how the fatigue behavior and probabilistic properties of SAE1055 steel are related to its hardness level. SAE1055 steel was heat-treated using induction hardening. Five types of specimens were prepared (A: base material, B: through hardened material with HV390, C: through hardened material with HV510, D: through hardened material with HV700, and E: surface hardened material with HV700). Fatigue tests were performed under a stress ratio of R = -1 using a 4-point rotary bending fatigue tester. The fatigue behaviors were greatly influenced by the hardness, but the fatigue limit did not increase over a hardness of HV510. In addition, the effect of the hardness level on the failure mechanism was evaluated using a scanning electron microscope. The probabilistic properties of the fatigue life were investigated using a probabilistic S-N approach, and the effect of the hardness level on these properties was evaluated using a residue analysis.