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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Manufacturing Process Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Manufacturing Process Engineers
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Volume & Issues
Volume 7, Issue 4 - Dec 2008
Volume 7, Issue 3 - Sep 2008
Volume 7, Issue 2 - Jun 2008
Volume 7, Issue 1 - Mar 2008
Selecting the target year
Development of a Swing-Arm Type Polishing Machine for Large Optics
Kim, Jin-Wook ; Kim, Ock-Hyun ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 3~7
A polishing machine adopting a new unique structural mechanism has been developed, named as a swing-arm type polishing machine. The mechanism is such that the tool path tracks on a spherical surface, of which the diameter is adjusted by setting lip the machine mechanism properly. It has a strong benefit especially for polishing axis-symmetric concave mirror surfaces. The swing-arm type polishing machine with 5-axes has been designed in order to polish a concave mirror surface lip to diameter of 2 meters. The drawings are made using 3D CAD and strain-stress analysis has been done by finite element method. AC servo-motor has been used to move the swing arm and a operating software has been developed using a LapVIEW tool. Result of the test run was satisfactory which convinces the usefulness of the swing-arm type polishing machine.
Optimization Method for a Coupled Design, Considering Robustness
Kang, Dong-Heon ; Song, Byoung-Cheol ; Park, Young-Chul ; Lee, Kwon-Hee ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 8~15
Current trend of design technologies shows engineers to objectify or automate the given decision-making process. The numerical optimization is an example of such technologies. However, in numerical optimization, the uncertainties are uncontrollable to efficiently objectify or automate the process. To better manage these uncertainties, Taguchi method, reliability-based optimization and robust optimization are being used. Based on the independence axiom of axiomatic design theory that illustrates the relationship between desired specifications and design parameters, the designs can be classified into three types: uncoupled, decoupled and coupled. To best approach the target performance with the maximum robustness is one of the main functional requirements of a mechanical system. Most engineering designs are pertaining to either coupled or decoupled ones, but these designs cannot currently accomplish a real robustness thus a trade-off between performance and robustness has to be made. In this research, the game theory will be applied to optimize the trade-off.
Study on Fracture at Material under Dynamic Load
Cho, Jae-Ung ; Han, Moon-Sik ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 16~22
This study was analyzed dynamically by finite element method about the results of experiments which materials were applied by dynamic load. And they were compared with each other as the simulation data applied onto dynamic impact velocities of 6.4, 16.7 and 18.47m/s. The crack energy release rate, von-Mises stress and the displacement according to the load applied by block were calculated numerically by computer. As the numerical simulation data of specimen analyzed in this study approached the experimental data, the inspection of this specimen model suggested in this paper could be reasonable for the numerical simulation.
Improvement of Surface Roughness by the Cutting Speed Control for Turning Operation
Choi, Jong-Hwan ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 23~30
As a basic machining process, turning is a widely used machining process in which a single-point cutting tool removes material from the surface of a rotating material. A common method of evaluating machining performance is to measure the surface roughness. In a turning operation, it is important to select cutting conditions for achieving high cutting performance. As a rule, cutting conditions can be classified into feed rate, depth of cut and insert radius. While cutting process even though cutting conditions are optimized, the average roughness can be deterioration due to wear of the cutting tool edge. In this study, the aim is to maintain the average roughness even though the cutting condition is irregularly changing within the predictable range due to the working environment. First, the surface roughness model influenced by cutting conditions is constructed based on the experimental results in a turning operation, Second, applying the sliding mode control theory to the turning operation model which is composed of the surface roughness model and the motor transfer function, the surface roughness is closed to the desired value. Finally, the effectiveness of this approach is demonstrated through the computer simulation.
Numerical analysis of the magnetic fluid velocity and pressure distribution according to the various magnetic field
Song, Joon-Ho ; Lee, Yuk-Hyung ; Bae, Hyung-Sub ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 31~37
In this paper, we analyzed the dynamic behavior of magnetic fluid in a circular pipe with multiple permanent magnets. Magnetic fluid react on magnetic field against the normal fluid. In other words, magnetic fluid flow has the electromagnetism and fluid mechanics. So magnetic fluids has studied about the fluids properties and experiment. In this paper we studied the magnetic fluids velocity and pressure distribution for the novel type actuator. Because the velocity and pressure distribution is the important element of the magnetic fluids flow. First, we analyzed the Maxwell equation for the multiple permanent magnet and then concluded the governing equations for the magnetic fluid flow using the equation of Navier-Stokes. And, we simulated the dynamic behavior of magnetic fluid flow using the FEM(Finite Element Method). And we illustrated the relation between magnetic field and dynamic behavior of magnetic fluid flow.
A Study on the Rheology Characteristics of Magnetic Fluids in a Circular Pipe
Jeon, Eon-Chan ; Park, Joung-Woo ; Kim, Tae-Ho ; Kim, Soo-Yong ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 38~44
In the present paper, we theoretically analyze the flow of magnetic fluids in a circular pipe with a vertical magnetic field and investigate the magnetic response by the external magnetic field. Theoretical study through the governing equation derived by Siliomis is carried out with numerical analysis by the Gauss Elimination Method. Using polar and magnetic effect parameters, theoretical equations and distributions for the velocity, apparent viscosity as the magnetic response are shown. Especially, in the region of strong magnetic field the specific property is appeared by finding a critical magnetic effect parameter for a polar effect parameter.
A Study on the Design of Upward and Downward Traverse Units in an Automatic Object Changer Unit to Establish a Flexible Production System (Part 1)
Park, Hoo-Myung ; Kang, Jin-Kab ; Lee, Yong-Joong ; Ha, Man-Kyung ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 45~51
The objective of this study is to develop an automatic object changer unit to improve processing problems existed in the conventional horizontal machining center. In order to perform this objective, a upward and downward traverse unit in which a unit that consists of a motor and reducer, chain and sprocket wheel, and upper and lower base employed in an automatic object changer unit performs sliding contact motion in a frame was designed. To achieve this design, constraint conditions for the upward and downward traverse unit first designed. Then, an operation mechanism was designed and that was introduced as a sum of kinetic energy for the sprocket wheel and upper and lower base based on the moment of inertia, which is the kinetic energy of the converted upward and downward traverse unit in the side of the reducer. In addition, The work required to rotate the converted upward and downward traverse unit in the side of the reducer by one revolution can be calculated using the sum of work that is required in the sprocket wheel and upper and lower base that is a part of the upward and downward traverse unit. Furthermore, the converted equation of motion in the side of the motor can be introduced using the equation of motion using the converted upward and downward traverse unit in the side of the motor. Then, Then, a proper motor can be determined using predetermined specifications employed in the motor and several parameters in the upward and downward traverse unit in order to verify such predetermined specifications. Also, a design of a horizontal traverse unit that performs sliding motion on a upward and downward traverse unit and simulation that verifies the results of this design are required as a future study.
A Study on the Design of Horizontal Traverse Units in an Automatic Object Changer Unit to Establish a Flexible Production System (Part 2)
Park, Hoo-Myung ; Sung, Jae-Kyung ; Lee, Yong-Joong ; Ha, Man-Kyung ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 52~59
The objective of this study is to develop an automatic object changer unit to improve processing problems existed in the conventional horizontal machining center. To achieve this goal, this study designed a horizontal transfer as the second project continued to the first project that designed a upward and downward traverse unit. A horizontal traverse unit shows a symmetric structure and consists of frame, which consists of four unit tools, motor and reducer, which are fixed at a frame, operation unit with pinions, first traverse unit, and second traverse unit. Constraint conditions based on the operation mechanism with these elements were configured and obtained following results after modeling a model for a traverse motor. In the kinematic expression of sliding motion with one degree of freedom, the sliding motion is constrained. Also, the rack 3 installed at a frame is used to configure possible kinematic constraint conditions of the rack 2 according to the rolling motion of the pinion 2 in the first traverse unit. In addition, the moment of inertia that is a type of kinetic energy in a converted horizontal traverse unit in the side of the reducer can be applied to introduce the moment of inertia of a converted horizontal traverse unit in the side of the reducer by using the sum of kinetic energy in the rack and pinion, which is a part of the horizontal traverse unit. Also, the equation of motion of the converted upward and downward traverse unit in the side of the motor using the equation of motion of the motor. Furthermore, the horizontal traverse unit predetermines the mass of the first and second traverse unit and applied load including the radius and reduction ratio of the pitch circle in the pinion 1 and applied load to the rack 2. Then, a proper motor can be determined using several parameters in the upward and downward traverse unit in order to verify such predetermined specifications. In future studies later this study, a simulation that verifies the results of the previous two stages of studies using a finite element method.
A Study on the Displacement Magnification Mechanism of Two-Lever System using Flexure Hinge
Jea, Wone-Soo ; Ye, Sang-Don ; Min, Byeong-Hyeon ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 60~65
The high-technology industries including a semi-conductor and an information communication need an ultra-precision technology from the technological points of view. Nano technology based on an ultra-precision technology is being studied to overcome the delicate technology that may occur in the semi-conductor fields. Then, the transferring equipment with high resolution and long displacement becomes an important technology. The goal of this study is to analyze the displacement magnification mechanism driven by piezoelectric actuator which has high resolution and fast response characteristics using flexure hinge with the merits of soft displacement, negligible back-lash and stick-slip, and no-lubrication. The analyses to reduce the magnification losses occurred during the magnification process are performed using ANSYS software based on FEM. The five design variables such as arm thickness, thickness of hinge, radius of hinge, length of input side at the 1st lever and magnification ratio of 1st lever are optimized to induce the maximum magnification ratio using Taguchi method.
Stress Analysis of Blanking Plate Applied by Press
Cho, Jae-Ung ; Han, Moon-Sik ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 66~71
The data of the deformation and the stress according to time are studied at upper model of press and lower model of the blanking plate applied by press with the width, length and height of 0.4 m and 0.6 m respectively. The press is pushing downward on the plate fixed at the lower floor. These data are compared and investigated through this study. By using these results, there is the maximum deformation at 4 comers in the lower plate model of aluminium alloy fixed at lower floor. This deformation incase of elapsed time of 0.6 second becomes 4 times as much as in case of elapsed time of 0.2 second. The quantity of deformation at the lower plate model becomes more than at the upper press model to the extent of 10%. At the lower plate model of aluminium alloy, there is the maximum Von-Mises equivalent stress at 4 comers and both sides of middle area on the lower plate model of aluminium alloy. This stress in case of elapsed time of 0.6 second becomes 6 times as much as in case of elapsed time of 0.2 second. The Von-Mises equivalent stress of lower plate model becomes 2 times as much as that of upper press mode.
Detection of Tool Failure by Wavelet Transform
Lee, Dong-Weon ; Park, Jong-Sung ;
Journal of the Korean Society of Manufacturing Process Engineers, volume 7, issue 2, 2008, Pages 72~77
In this study, we propose and develop PDMS-based modular actuators. The microactuator which looks like a small insect uses thermal expansion power of the PDMS (polydimethylsiloxane;
184 silicone elastomer). The PDMS-based microactuator provides a large displacement due to a high thermal expansion coefficient (approximately 310ppm). The microacruator with 1mm length 350
width is optimized by using a numerical analysis. The shape of the PDMS actuatoris variously designed. They are placed at several positions to find the optimal position that provides a high transformation ratio. The PDMS-based microactuators are fabricated using a conventional micromaching technique. The fabricated microactuator is heated using a hot-plate. The actuator displacement is measured as a function of temperature from
. The experimental results are compared to the simulation result. When heating temperature up to
is applied to the PDMS actuator, each V-groove-shaped joint is actuated 30
. Anotherdesign of the microactuator has a maximum displacement of about 656mm.