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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
Development of Power Management Strategies for a Compound Hybrid Excavator
Kim, Hak-Gu ; Choi, Jae-Woong ; Yoo, Seung-Jin ; Yi, Kyoung-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1537~1542
DOI : 10.3795/KSME-A.2011.35.12.1537
This paper presents the power management strategies for a compound hybrid excavator. The compound hybrid excavator has been replaced the hydraulic swing motor to the electric swing motor. This excavator requires a proper control algorithm to regulate the energy flow between the mechanical coupling and the electric devices. The controller should improve fuel economy and maintain the super capacitor voltage within a proper range. A thermostat controller and ECMS controller are designed such that these objectives can be achieved. The thermostat controller regulates the power of the engine-assist motor on the basis of the super capacitor voltage, and the ECMS controller determines it using the real-time fuel minimization strategy based on the concept of equivalent fuel. Simulation results showed that by using the hybrid excavator, the fuel economy becomes about 20% higher than that obtained using the conventional excavator and that the ECMS controller outperforms the thermostat controller.
Structural Analysis for Design of Anchor Straps for a Large-Scale LNG Storage Tank with Corner Protection and Inner Tank
Jin, Chengzhu ; Ha, Sung-Kyu ; Kim, Seong-Jong ; Lee, Young-Hwan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1543~1548
DOI : 10.3795/KSME-A.2011.35.12.1543
Structural analysis is performed to design anchor straps for a large-scale-liquefied-natural-gas (LNG) storage tank with corner protection and an inner tank by considering structural integrity. Anchor straps made of 9% nickel steel are attached to the inner tank, corner protection, and concrete raft to prevent the failure of the inner tank during both normal and emergency operating conditions. Two finite element (FE) models were analyzed in this study. One is a stand-alone model of the anchor strap, while the other is an extended model of the substructure of the anchor strap, inner tank, and corner protection. Three-dimensional shell elements are used to effectively assess the bending and axial behavior of structures. The Tresca stress values in each part of the two models are calculated for operation under five different load-condition cases: normal operation, leakage of the LNG, hydro test, and two earthquake conditions.
Creep Behavior of Plastics Used in Automobile Instrument Panels
Kim, Young-Sam ; Jeon, Chi-Hoon ; Tumur-Ochir, Erdenebat ; Yum, Young-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1549~1556
DOI : 10.3795/KSME-A.2011.35.12.1549
Tensile and creep tests were performed at various temperatures to investigate the mechanical properties of plastics used in automotive instrument panels. Mechanical properties such as Young's modulus and Poisson's ratios changed markedly with the test temperature. Three-point bending creep tests were performed for three kinds of plastics under four loading conditions. Coefficients in the time-hardening power law creep equation were obtained from the experiment, and the creep behavior was represented by a simple expression. The results of finite element creep analysis showed good agreement with the experimental results, while the difference between the numerical and experimental results increased with the load.
Computational Analysis of Bearing Screw Used in Lead Screw
Kim, Min-Gun ; Cho, Seok-Swoo ; Kim, Dong-Youl ; Kim, Yo-Seb ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1557~1562
DOI : 10.3795/KSME-A.2011.35.12.1557
In order to assess the stiffness of bearing screw used for lead screw, finite element analysis on stress and fatigue life of bearing screw has been performed. Based on these analysis, fatigue life dominant model of bearing screw was proposed. This improved model introduces a fillet to release the concentrated stress generated in the vicinity of bearing screw hole. This paper also considered the strength suitability when the bearing screw manufactured in W company was applied to X-ray CT.
Finite Element Analysis of Sound Transfer Characteristics for Middle Ear
Gal, Young-Min ; Baek, Moo-Jin ; Lee, Doo-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1563~1571
DOI : 10.3795/KSME-A.2011.35.12.1563
In this study, we developed a finite element model of the human middle ear has been developed to calculate itsfor sound transfer characteristics calculation. We usedThe geometric data forof ossicles, obtained byfrom micro-CT scanning, was used in order to develop the middle- ear FE model. A right- side temporal bone of a Korean cadaver was used for the micro-CT scanning. The developed FE model includes three ossicles, the tympanic membrane, ligaments, and muscles. We calculated theA sound transfer function from the tympanic membrane to the stapes footplate was calculated. The sound transfer function calculated vias of the FE model shows good agreement with measured responses over the 10- kHz frequency band. To measureidentify the sensitivityies of the middle- ear function due to material property variation, we studied several parameters studies have been fulfilled using the middle ear FE model. TAs a result the stiffness property of the incudostapedial joint had the greatest influence onwas the most influential to the middle- ear sound transfer function among the parameters.
Three-dimensional Locomotion and Drilling Microrobot Using Electromagnetic Actuation System
Li, Jie ; Choi, Hyun-Chul ; Cha, Kyoung-Rae ; Jeong, Se-Mi ; Park, Jong-Oh ; Park, Suk-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1573~1578
DOI : 10.3795/KSME-A.2011.35.12.1573
In this study, a novel electromagnetic microrobot system with locomotion and drilling functions in threedimensional space was developed. Because of size limitations, the microrobot does not have actuator, battery, and controller. Therefore, an electromagnetic actuation (EMA) system was used to drive the robot. The proposed EMA system consists of three rectangular Helmholtz coil pairs in x-, y- and z-axes and a Maxwell coil pair in the z-axis. The magnetic field generated in the EMA coil system could be controlled by the input current of the EMA coil. Finally, through various experiments, the locomotion and drilling performances of the proposed EMA microrobot system were verified.
Dynamic Analysis of Wave Energy Generation System by Using Multibody Dynamics
Jang, Jin-Seok ; Sohn, Jeong-Hyun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1579~1584
DOI : 10.3795/KSME-A.2011.35.12.1579
This paper discusses an energy system that can convert wave energy into electrical energy. This wave energy generation system is movable and has 12 arms and one generator. A multibody dynamic model for this system is established by using kinematic constraints. A gear mechanism, several kinematic constraints, and force elements are included in the model. Wave forces are obtained numerically from the time domain formulation based on the Morison equation. The MSC/ADAMS program is employed to carry out dynamic analysis of the wave energy generation system. The dynamic behavior responses of this system are analyzed for design verification. According to the results of the dynamic analysis, the yaw motion is relatively stable and kinetic energy sufficient to generate electrical energy is obtained when the wave height exceeds 1m.
Development of Exoskeleton-Type Data Glove for Position/Force Feedback
Kim, Min-Jeong ; Kim, Dae-Gyeong ; Park, Han-Gil ; Kim, Ui-Kyum ; Choi, Byung-June ; Choi, Hyouk-Ryeol ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1585~1591
DOI : 10.3795/KSME-A.2011.35.12.1585
In this paper, we present a new exoskeleton-type data glove that can sense the movement of the human finger and reflect the force to the finger. The data glove is designed on the basis of the skeletal structure of the human hand, and the finger module has 1 degree-of-freedom because it includes three four-bar mechanism joints in series and a wire-coupling mechanism. In addition, the transmission ratio of the finger module is maintained at 1:1.4:1 over the entire movement range, and hence, the module can perform both extension and flexion. In addition, to enable adduction/abduction motion of the human hand, a unique MCP joint is designed by using two universal joints. To validate the feasibility of the data glove, master-slave control experiments based on force-position control between the data glove and the robot hand are conducted.
Parameter Selection for Condition Monitoring of LCD Conveyance Robot by Using Vibration Signals
Jang, Jun-Hyuk ; Jung, Won-Young ; Lee, Kyu-Ho ; Chung, Jin-Tai ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1593~1598
DOI : 10.3795/KSME-A.2011.35.12.1593
The purpose of this study is to perform parameter selection and develop a method for the condition monitoring of an LCD conveyance robot. To determine the vibration characteristics of the driving part of the robot, the gear mesh frequency (GMF) of the speed-reducing gearbox is calculated and confirmed by frequency analysis. In order to ensure reproducibility of the measured data, an appropriate working pattern is selected and experiments are carried out. For condition monitoring of the robot, a wireless measurement system is constructed and used in parameter selection, with the GMF as the center. A method involving the use of the standard deviation of the measured data and another method involving the use of multiple value of amplitude are proposed.
A Study on Experimental Test of a Small Scale Hingeless Rotor
Kim, Joune-Ho ; Song, Keun-Woong ; Joo, Gene ; Suk, Jin-Young ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1599~1606
DOI : 10.3795/KSME-A.2011.35.12.1599
It is possible to study the load characteristics of full-scale hingeless rotor with the changing of physical smallscaled configurations such as rectangular and paddle blades, and metal and composite hubs. In this study, a static test, and a ground and wind-tunnel test were carried out using small-scale rotor models. The static test was carried out to confirm structural stiffness, characteristics of inertia, natural frequency, and damping ratio of rotors, and the ground and wind-tunnel test was carried out to confirm the stability and aerodynamic characteristics under hovering and forward flight conditions. According to the test results, the vertical load in the case of a combination of a small composite hub with paddle blades was higher than that in the case of a metal hub with paddle blades at same condition. Further, it was confirmed that the restraint of the combination of composite hub can be more flexible than the metal hub for the motion of paddle blades.
Motion Analysis and LQG/LTR Control of a Proportional Solenoid Valve
Kim, Ki-Bum ; Kim, In-Soo ; Kim, Yeung-Shik ; Kim, Jun-Sik ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1607~1612
DOI : 10.3795/KSME-A.2011.35.12.1607
In this study, dynamic analysis of a proportional solenoid valve is performed, and an LQG/LTR controller with an integrator is designed to control the proportional solenoid valve. The dynamic characteristic of a valve is identified using experimental data by employing the frequency-domain modeling technique. The purpose of LQG/LTR control with an integrator is to enhance the system response and to improve the tracking accuracy for a complex input signal. Experimental tests are performed to verify the performance of the controller, and the results prove the high performance of the controller.
Mechanism Design Using a Mechanism Configuration Method
Lee, Jang-Yong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1613~1618
DOI : 10.3795/KSME-A.2011.35.12.1613
Analysis method for mechanism has been fully developed and relatively easy work compared to mechanism synthesis. Developing or creating a new mechanism for a given task is a creative job. In this case, a few theories are developed such as type synthesis. However, these methods are not sufficient for mechanism designers to sufficientely take into account alternative mechanism models during the initial phase of the mechanism design process. This paper presents the configuration design of mechanisms using graphical representation in the conceptual design stage. In this stage of kinematic synthesis, one needs to select mechanisms and configure appropriately to realize the desired motion of a machine. Graphical representation of mechanisms is proposed in this paper to help a designer to be highly creative and efficient in the initial design process. It is possible to easily design and analyze the mechanism of a machine by using this method.
Determination of Molding Conditions of Double-Shot Injection Mold for the Computer Mouse via Three-Dimensional Injection Molding Analysis
Ahn, Dong-Gyu ; Park, Min-Woo ; Park, Jeong-Woo ; Kim, Hyung-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1619~1625
DOI : 10.3795/KSME-A.2011.35.12.1619
The objective of this study determine the molding conditions of a double-shot injection mold for fabricating a computer mouse using different materials, by performing three-dimensional injection molding analysis. In order to select the optical injection molding conditions, the effects of the injection time, the maximum injection pressure, the effect of packing time on the injection molding characteristics, and the product qualities were quantitatively examined. From the results of the injection molding analysis, the optimal injection molding conditions of the double-shot injection mold, which leads the molded product to the minimized shrinkage and deflection, were estimated. The results of the injection molding experiments, showed that an appropriate computer mouse can be fabricated using different materials when the identified optimal injection molding conditions are adopted.
Thermal-Fluid Coupled Analysis for Injection Molding Process by Considering Thermal Contact Resistance
Sohn, Dong-Hwi ; Kim, Kyung-Min ; Park, Keun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1627~1633
DOI : 10.3795/KSME-A.2011.35.12.1627
Injection molds are generally fabricated by assembling a number of plates in which the core and cavity components are assembled. This assembled structure has a number of contact interfaces where the heat transfer characteristics are affected by thermal contact resistance. In previous studies, numerical approaches were investigated to predict the effect of thermal contact resistance on the temperature distribution of injection molds. In this study, thermal-fluid coupled numerical analyses are performed to take into account the thermal contact effect on the numerical evaluation of the mold filling characteristics. Comparisons with experimental results show that the proposed coupled analysis provides more reliable results than the conventional analyses in predicting the mold filling characteristics by taking into account the effect of thermal contact resistance inside the injection mold assembly.
Design of Cooling System of Over-molding Mold for Socket Component of Automobile Wiper
Lee, Dong-Gi ; Park, Min-Woo ; Ahn, Dong-Gyu ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1635~1640
DOI : 10.3795/KSME-A.2011.35.12.1635
The objective of this study is to design of a cooling system of the over-molding mold for a socket component of an automobile wiper by performing numerical analyses. Hot spots in which the temperature distributions are higher than those of other region, were estimated by an initial over-molding analysis for the initial design of the mold. On the basis of the initial over-molding analysis, two types of cooling system designs with a linear cooling channel and a volumetric heat sink, were considered to improve the cooling characteristics of hot spots. To obtain an appropriate cooling system design, the effects of the diameter and the position of the linear cooling channels on the cooling characteristics and the product qualities were quantitatively examined. In addition, the effects of the design of the volumetric heat sink on the cooling characteristics and deformation distributions in the molded product were investigated. The results of the over-molding analysis of the two types of cooling systems showed that the multi-sliced over-molding mold with a volumetric heat sink can improve both the product quality and the cooling characteristics of the mold.
A Study on Polishing of Grooved Surface by the Second-Generation Magnetic Abrasive Polishing
Kim, Sang-Oh ; Lee, Sung-Ho ; Kawk, Jae-Seob ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1641~1646
DOI : 10.3795/KSME-A.2011.35.12.1641
The second-generation magnetic abrasive polishing is one of the nontraditional machining technologies newly developed. Because of the flexibility effect in magnetic abrasive polishing, the precise and mirror like surface can be obtained during this process. In this study, magnetic abrasive polishing process was applied in small grooved surface. As a result, it was seen that the flexible magnetic abrasive tool was effective to remove burrs on the edge of the groove. However, the efficiency of magnetic abrasive polishing at the slot was very low according to increasing depth and width of slot. So, correlation between geometric parameters, such as the depth and width, and surface roughness was evaluated and the minimum width for suitable polishing was found by experimental results.
Modeling of Cooling Channels of Injection Mould using Functionally Graded Material
Shin, Ki-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1647~1653
DOI : 10.3795/KSME-A.2011.35.12.1647
The cycle time in injection moulding greatly depends on the cooling time of the plastic part that is controlled by cooling channels. Cooling channels are required to facilitate the heat transfer rate from the die to the coolant without reducing the strength of the die. Employing layered manufacturing techniques (LMT), a die embedding conformal cooling channels can be fabricated directly while conventional cooling channels are usually made of straight drilled hole. Meanwhile, H13 tool steel is widely used as the die material because of its high thermal resistance and dimensional stability. However, H13 with a low thermal conductivity is not efficient for certain part geometries. In this context, the use of functionally graded materials (FGMs) between H13 and copper may circumvent a tradeoff between the strength and the heat transfer rate. This paper presents a method for modeling of conformal cooling channels made of FGMs.
Laser Micro-Welding Process in which Magnetic Fields are Applied
Lee, Woo-Ram ; Lee, Chul-Ku ; Kim, Joo-Han ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1655~1662
DOI : 10.3795/KSME-A.2011.35.12.1655
We have conducted a study on stainless steel laser-welding materials by using a laser beam for the evaluation. Stainless steel used in a rust and excellent thermal deformation has a variety of application. In this study, to improve the mechanical properties of stainless steel, a 50 W laser thermal source is used and magnetic fields are applied, on the basis of suggestions. The mechanical properties and performance are evaluated by performing a numerical analysis, tensile test, and shape, microstructure, and hardness test. The results show that the mechanical properties of improve increased speed the melting pool, tensile strength of 16 kPa rise, run into the melting zone and hardness 7 Hv.
Characteristics of Heat Treatment on Different Materials during Laser Surface Hardening of Cast Iron for Die
Kim, Jong-Do ; Song, Moo-Keun ; Hwang, Hyun-Tae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 12, 2011, Pages 1663~1668
DOI : 10.3795/KSME-A.2011.35.12.1663
Surface hardening treatment is required to improve the wear-resistance of press die because severe abrasion of die occurs during the drawing process in which the forming of the automotive body is completed and during the trimming process in which the unnecessary parts are cut. In this study, experiments on the laser surface treatment of press die are performed. Specimens are heat-treated separately at certain plate and edge position by using a diode laser to carry out suitable surface hardening treatment to reduce the wear during the drawing and the trimming processes, and the proper conditions for heat treatment are found. Spheroidal and flake graphite cast iron specimens are used, and the heat treatment characteristics of the two materials are compared. From the results of the study, it is confirmed that the heat treatment characteristics differed depending on the materials.