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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Manufacturing Technology Engineers
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Journal DOI :
The Korean Society of Manufacturing Technology Engineers
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Volume & Issues
Volume 21, Issue 6 - Dec 2012
Volume 21, Issue 5 - Oct 2012
Volume 21, Issue 4 - Aug 2012
Volume 21, Issue 3 - Jun 2012
Volume 21, Issue 2 - Apr 2012
Volume 21, Issue 1 - Feb 2012
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Design and Fabrication of PZT Disc Actuated Micro Pump for Bio-Applications (I): Optimal Design of Ring-shaped Flab Valve Module
Kim, Hyung-Jin ; Seo, Young-Ho ; Kim, Byeong-Hee ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 355~361
DOI : 10.7735/ksmte.2012.21.3.355
Though a micro pump is a crucial element in miniaturized bio-fluidic systems or drug delivery systems, it has some intrinsic disadvantages such as backward flow, pulsation of flow, low repeatability and producibility, and high cost. To overcome these limitation, a PZT disc actuated micro pump including a novel ring-shaped multi-flap check valve is introduced. To enhance the performance of the micro pump, the static behaviour of flap valve module and the micro fluidic behavior of fluids are numerically modelled and analyzed. As results of the numerical analysis, the optimal dimension and configuration of the ring-shaped multi flap valve are
mm and 2 (inlet side)
(outlet side) type. The obtained maximum flow rates and flow resolution are about 90 ml/min and 30
Design and Fabrication of PZT Disc Actuated Micro Pump for Bio-Applications (II): Optimal Design & Fabrication of Embedding-type PZT Module
Kim, Hyung-Jin ; Chang, In-Bae ; Seo, Young-Ho ; Kim, Byeong-Hee ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 362~367
DOI : 10.7735/ksmte.2012.21.3.362
Though a micro pump is a crucial element in miniaturized bio-fluidic systems or drug delivery systems, most of the conventional micro pumps still have some limitations to miniaturize their controller system and to obtain the sufficient back pressure which can rise over the inner pressure of human body or experimental animals. In this paper, to overcome these limitation, a new PZT disc and its controller were designed and fabricated to get the sufficient flowrate and the back pressure with guaranteeing embeddability of the controller into pumping body. The amplitudes of the disc deflections were as large as 40
at 200 V - 100 Hz condition. As results of experiments, the flow rate and the back pressure increase when the frequency increases. The obtainable maximum flow rate and back pressure are 5.2 ml/min at 95 Hz and 13.14 kPa at 90 Hz respectively.
Durability Design of a Passenger Car Front Aluminum Sub-frame using Virtual Testing Method
Nam, Jin-Suk ; Shin, Hang-Woo ; Choi, Gyoo-Jae ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 368~375
DOI : 10.7735/ksmte.2012.21.3.368
Durability performance evaluation of automotive components is very important and time consuming task. In this paper, to reduce vehicle component development time and cost virtual testing simulation technology is used to evaluate durability performance of a passenger car front aluminum sub-frame. Multibody dynamics based vehicle model and virtual test simulation model of a half car road simulator are validated by comparisons between rig test results and simulation results. Durability life prediction of the sub-frame is carried out using the model with road load data of proving ground which can evaluate accelerated durability life. We found that the durability performance of the sub-frame is sufficient and it can be predicted within short time compared to rig test time.
Hardness Estimation of Compressor Journal for a Use of Instrumented Indentation Techniques
Kwak, Sung-Jong ; Jin, Ji-Won ; Kim, Tae-Seong ; Noh, Ki-Han ; Kang, Ki-Weon ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 376~381
DOI : 10.7735/ksmte.2012.21.3.376
This paper deals with application of instrumented indentation technique for quality inspection methodology for automobile component. For this, the instrumented indentation tests were performed the normal and cracked compressor journal, which is made from spheroidal graphite cast iron and utilized in air-conditioning system. And the Brinell hardness was estimated using the unloading slope and maximum indentation force. With the aid of Normal distribution, this Brinell hardness was statistically compared and analyzed with hardness measured by indentation hardness tests. Also, application possibility of reliability-based quality inspection criteria for compressor journal was evaluated through the probabilistic analysis for the Brinell hardness estimated by instrumented indentation technique.
Multi-layer Glass Cutting by Femtosecond Laser
Shin, Hyun-Myung ; Lee, Young-Min ; Choi, Hae-Woon ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 382~386
DOI : 10.7735/ksmte.2012.21.3.382
A femtosecond laser with 775nm central wavelength and 150 fs of temporal pulse width was used for multi layered glass cutting applications. Ultrashort pulse was effectively used for clean glass cutting with
depth and minimum cutting width. Laser beam was split to two stages and focused on the top surfaces of each layer. Ablation threshold of used glass was measured to be
. In experiments, 200mW laser power and 1mm/s scanning speed was used for preliminary experiment. Air gap was the major defect occurring parameter and laser power was less sensitive to glass cutting in the experiment. The maximum cutting speed was measured to be 60mm/min with 2kHz, however, Maximum 3m/min cutting speed can be achievable with a commercially available laser with 100kHz.
A Study On Prediction Model of Cutting Conditions for Draft Angle Control
Cho, Ji-Hyun ; Song, Byeong-Uk ; Seo, Tae-Il ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 387~393
DOI : 10.7735/ksmte.2012.21.3.387
It is very difficult to determine suitable cutting conditions in order to obtain accurate cutting profiles because machining errors caused by tool deflection depend upon cutting conditions. In this study the relationship between real cutting profiles (inclined shapes and machining errors) and cutting conditions was modeled in order to fabricate draft angle on micro molds. CCD (Central Composite Design) of DOE (Design Of Experiment) and RSM (Response Surface Method) were applied in order to model the relationship between cutting conditions and machining errors. In order to use CCD the range of radial depth of cut was chosen by
and the range of feedrate was chosen by 200-300mm/min, and 9 points of cutting conditions were chosen inside determined ranges. Then, actual cutting processes were carried out as respect to 9 points of cutting conditions, draft angles and real cutting profiles were measured on cutting profiles, each response surface function was determined by conducting response surface analysis and the functions were represented by 3-dimensional graphs, contour lines and
matrices. Consequently it is possible to determine suitable cutting conditions in order to obtain arbitrary given draft angles and cutting profiles by using modeling. To validate proposed approach in this study suitable cutting conditions were determined by modeling in order to obtain arbitrary given draft angle and cutting profile, and actual cutting processes were carried out. About 95% of good agreement between predicted and measured values was obtained.
A Study on the Process Optimization of Brush Deburring Grinding System
Shin, Kwan-Soo ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 394~400
DOI : 10.7735/ksmte.2012.21.3.394
Due to the increasing demand for carious methodologies, the quality improvement of products were introduced. A brush, the most frequently used type of grinding process, is one of the deburring. In order to produce consistent burr shape, various machining conditions have been combined and applied to disk grinding process. By tool dynamometer, acoustic emission sensor and acceleration sensor depend on changes in processing conditions(depth of engagement, cutting speed, workpiece position, workpiece orientation, cutting time) signals were obtained for brush deburring grinding system. Root mean square obtained by processing the signal processing conditions by analyzing the characteristics of deburring is to derive the optimum conditions.
Design of the Air Pressure Pick-up Head for Non-Contact Wafer Gripper
Kim, Joon-Hyun ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 401~407
DOI : 10.7735/ksmte.2012.21.3.401
The recent manufacturing process in the thin wafers and flat panel necessitate new approaches to reduce handling fragile and surface-sensitive damage of components. This paper presents a new pneumatic levitation for non-contact handling of parts and substrates. This levitation can achieve non-contact handling by blowing air into an air pressure pick-up head with radial passages to generate a negative pressure region. Negative pressure is caused by the radial air flow by nozzle throat and through holes connecting to the bottom region. The numerical analysis deals with the levitational motion with different design factors. The dynamic motion is examined in terms of force balance(dynamic equilibrium) occurring to the flow field between two objects. The stable equilibrium position and the safe separation distance are determined by analyzing the local pressure distribution in the fluid motion. They make considerable design factors consisting the air pressure pick-up head. As a result, in case that the safe separation distance is beyond 0.7mm, the proposed pick-up head can levitate stably at the equilibrium position. Furthermore, it can provide little effect of torque, and obtain more wide picking region according to the head size.
Deformation Analysis of a Metal Mask for the Screen Printing of Micro Bumps
Lee, K.Y. ; Lee, H.J. ; Kim, J.B. ; Park, K. ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 408~414
DOI : 10.7735/ksmte.2012.21.3.408
Screen printing is a printing method that uses a woven mesh to support an ink-blocking stencil by transferring ink or other printable materials in order to form an image onto a substrate. Recently, the screen printing method has applied to micro-electronic packaging by using solder paste as a printable material. For the screen printing of solder paste, metal masks containing a number of micro-holes are used as a stencil material. The metal mask undergoes deformation when it is installed in the screen printing machine, which results in the deformation of micro-holes. In the present study, finite element (FE) analysis was performed to predict the amount of deformation of a metal mask. For an efficient calculation of the micro-holes of the metal mask, the sub-domain analysis method was applied to perform FE analyses connecting the global domain (the metal mask) and the local domain (micro-holes). The FE analyses were then performed to evaluate the effects of slot designs on the deformation characteristics, from which more uniform and adjustable deformation of the metal mask can be obtained.
A Study on Dust Collection Efficiency of Axial-vane Type Cyclone for Oil Mist
Yi, Chung-Seob ; Shin, Hae-Joong ; Lee, Chi-Woo ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 415~420
DOI : 10.7735/ksmte.2012.21.3.415
Dust collecting performance of axial-vane type cyclone for oil mist was analyzed in this study. For predicting cut diameter size of cyclone, the number and angle of vane (
) was calculated by CFD. As the result,
was decreased as the number of vane was increased and the angle of inclination (
) decreased, and it cause strong swirl flow. Therefore, it could be confirmed that as the number of vane was increased and the angle of inclination was decreased, cut diameter size was decreased. Also, by verifying the results of CFD through experiment, the cut diameter size could be 2
of flow rate.
Bending Characteristic Evaluations Circular Cross-section Carbon Composite and Hybrid Structural Material
Kim, Jung-Ho ; Jeong, Jong-An ; Kim, Ji-Hoon ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 421~424
DOI : 10.7735/ksmte.2012.21.3.421
Carbon Fiber reinforced composite material can be designed for the optimized performances of structural member that have achieve appropriate mechanical properties with cross-sectional shape, fiber direction, stacking sequence and thickness. So there are needed extensive databases each optimal design of CFRP structural member by impact through the preparation of different shape, interface number, thickness and stacking angle. When pressure is applied to structural member, compression, bending and torsion is shown on the corresponding member. For the effective utilization of fiber reinforced composite material as main structural member, optimized design technology should be established to maximize mechanical properties for compression, bending and torsion. In this paper, CFRP prepreg sheet with different stacking angle is manufactured in CFRP and hybrid(Al+CFRP) with circular cross-section. Strength and stiffness is gotten respectively by flexure test. CFRP structure and hybrid structure can be compared with each other. The best design guideline can be analyzed by use of this study result.
A Study On Shape Design of Implant Systems For Bone Fracture Operations By Using Finite Element Method
Cho, Ji-Hyun ; Seo, Keum-Hee ; Seo, Tae-il ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 425~432
DOI : 10.7735/ksmte.2012.21.3.425
This paper investigates shape design processes of two implant systems for bone fracture treatment ; Bone plate and Interlocking nail system. These systems can directly fix fractured human bones by surgical operations. The bone plates consist of various shaped plates and implant screws for fixation of fractured human bones with various manual instruments allowing to handle them. The material corresponds to titanium alloy Ti6Al4V because it is harmless material for human body as well as significantly rigid. This system has to be suitably rigid as well as manually bended in orthopedic surgery operations. The Interlocking nail system is a kind of nail implanted inside fractured human bones. The shapes of these systems have to be suitably designed in order to endure various loads as well as avoid any damages. If various shaped prototypes would be fabricated and tested to design the optimal shapes, optimal shapes could be obtained but very long time and expensive costs must be required. In this paper finite element method was applied into these systems. Under various boundary conditions a series of structural analysis was conducted by using ANSYS. Finally important shape factors could be determined on the basis of the analysis results.
A Effects of Magnetic Field For Fiber Laser Micro Welding Process Using Carbon Steel of SCP1-S
Lee, C.K. ; Lee, W.R. ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 433~438
DOI : 10.7735/ksmte.2012.21.3.433
We have studied on welding dissimilar materials of Carbon steel SCP1-S by using laser beam. In this research we have performed some experiments to know the possibility of welding dissimilar materials using laser beam and magnetic fields by adjusting the power output of 35W laser. Other conditions of the experiments were as follows : the welding speed was varied in the range 10 m/min nitrogen gas was used as shield gas, the flow value of shield gas was ranged 10 L/min. In order to ascertain of the welded surface, we have done the tensile strength testing, the hardness testing and the microscope observation. As a result, we have found that tensile strength was the highest at the condition of the welding speed of 10mm/s, the flow value of 10 L/min, the gap of two materials 0, and the use of nitrogen gas. Above testings have also showed that the tensile strength was generally satisfactory since the penetration of welding was almost complete due to the thinness of the materials. In addition, the formation of the welded area was excellent when it had the highest tensile strength.
Analysis of Stress Singularity for the Excess Adhesive of Interface in Adhesively Bonded Joint
Chung, Nam-Yong ; Park, Cheol-Hee ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 439~445
DOI : 10.7735/ksmte.2012.21.3.439
The stress singularity for the excess adhesive on interface of adhesively bonded joint was investigated by using the 2-dimensional elastic boundary element method (BEM). To establish a reasonable strength evaluation method and a fracture criterion for the excess adhesive of interface in adhesively bonded joint, it is necessary to evaluate fracture parameters with various bonding conditions. Under the variations of adhesively bonded thickness (h) and diameter (d) for the excess adhesive, a stress analysis was performed, and from the results, the stress singularity index (
) and the stress singularity factor (
) were calculated. The variations have a great influences on the stress singularity for the excess adhesive of interface in adhesively bonded joint, and the
is reduced as the "h" and "d" increase.
The Development of Multi-Blades I.G.G Blower for Shipbuilding & Ocean
Jang, Sung-Cheol ; Park, Rae-Bang ; Hur, Nam-Soo ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 446~450
DOI : 10.7735/ksmte.2012.21.3.446
I.G.G is abbreviation for inert gas generator high temperature in cargo tank it desulfurize, exhaust and froze the gas that combined brimstone element and soot, then supply inert gas by blower and mack tank inside incombustible range this is equipment that nip in the bud the explosion. The blower for suppling inactivated gas has big impeller with heavy weight to achieve the high pressure, it causes a delay for first operation time and too much load is delivered to motor, total destruction by fire of motor is happen frequently. On this research, we will reduce the size and weight of impeller and install it with several stage, it makes an effect for reducing the first operation time. We also intend to contribute to efficient I.G.G. blower design by research a flow rate and pressure specialty from the diameter of impeller number of blades and size of casing.
Structural Analysis on the Wheel of Railway Vehicle
Cho, Jae-Ung ; Han, Moon-Sik ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 451~458
DOI : 10.7735/ksmte.2012.21.3.451
This study aims at the structural analysis with fatigue according to the configuration of railway vehicle wheel. Maximum equivalent stress or deformation is shown at the lower face in contact with wheel and rail. As model B has the maximum stress or deformation which becomes lower than model A, model B is shown to have more durability than model A. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to
Pa and the amplitude stress of 0 to
Pa, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE Bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of railway vehicle wheel by prevention and durability against its damage.
Hardware Configuration and Paradox Measurement for the Determination of Arrow Trajectory
Jeong, Yeong-Sang ; Yu, Jung-Won ; Lee, Han-Soo ; Kim, Sung-Shin ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 459~464
DOI : 10.7735/ksmte.2012.21.3.459
The point of impact, the shot group, and the flight traces depend on the combination of unique features which decide moving traces of the arrow (paradox of the archer, length of the arrow shaft, weight, angle of the feather, and spline of the arrow shaft). The more dense the impact points in the shot group and the earlier elimination of paradox of the archer, the higher assessment is given for the product. However, there is no way to objectively assess the efficiency and quality of the arrow, and there is no numeric data to be used as the basis for comparison with other products. Although capturing the images of flying arrow using a high-speed motion picture camera is possible, we are limited to observation from specific view angle only. Hence, the criteria for efficiency and quality assessment are mostly based on subjective opinions of experts or hunters, or review on consumers' remarks. In this paper, we propose a hardware composition that are based on three detection frames consisting of line lasers and photo diode arrays without the high-speed motion picture camera. Predicated on measured coordinates data, a nobel method for the archer's paradox measurement, a key parameter that determine the arrow's trajectory, and corresponding numerical analysis model is proposed.
Design of a Controller for Enhancing Positioning Performance of a PZT Driven Stage
Park, J.S. ; Jeong, Kyu-Won ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 465~472
DOI : 10.7735/ksmte.2012.21.3.465
This paper describes a new robust control algorithm which can be used to enhance the positioning performance of an ultra-precision positioning system. The working table is supported by flexure hinges and moved by a piezoelectric actuator, whose position is measured by an ultra-precise linear encoder. The system dynamics is very complicated because the movement of the table is governed by both the mechanical characteristics and those of the PZT actuator. So that, the dynamics of the stage was modeled roughly in this paper, and the overall system was formularized to solve the small gain problem. A series of experiments was conducted in order to verify the usefulness of the proposed algorithm. From the experimental results, the positioning performance such as the accuracy, the rise time and the hysteresis nonlinearity were greatly improved.
Analytic and Numerical Study for air Bubble Defect of UV-NIL Process
Seok, Jeong-Min ; Kim, Nam-Woong ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 473~478
DOI : 10.7735/ksmte.2012.21.3.473
In this paper, the air bubble formation mechanism in the rectangular and triangular line-and-space pattern during dispensing UV Nanoimprint Lithography (UV-NIL) at an atmospheric condition is studied. To investigate the air bubble formation, an analytic model based on geometric approach and a numerical model based on CFD(computational fluid dynamics) were used in the analysis. It was found in the numerical analysis that every time the flow front passed through a corner of the pattern, it proceeded with a newly formed shape, occurring due to interface reconfiguration, since the flow fronts were formed such that they minimized the surface energy. Moreover, the conditions for the air bubble formation were investigated by applying the analytic analysis based on geometric approach and the numerical analysis. Good overall agreement was found between the analytic and numerical analysis.
Analysis and Design of 3-DOF Parallel Mechanism Based on Kinematic Couplings
Wang, Wei-Jun ; Han, Chang-Soo ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 479~486
DOI : 10.7735/ksmte.2012.21.3.479
This paper presents a high-speed automatic micro-alignment system that is a part of an inspection machine for small-sized molded lenses of mobile phones, palm-top computers, and so on. This work was motivated by the shortcomings of existing highest-grade commercial machine. A simple tip/tilt/Z parallel mechanism is designed based on kinematic couplings, which is a 3-degree-of-freedom (3-DOF) moderate-cost alignment stage. It is used to automatically adjust the posture of each lens on the tray, which is impossible by the conventional instrument. Amplified piezoelectric actuators are used to ensure the accuracy and dynamic response. Forward kinematic analysis and simulation show that the parasitic motion is small enough compared to the actuator stroke. From the workspace analysis of the moving platform, it is clear that the output motion range satisfies the design requirements.
A Study on the LED Spotlight with a High Power using an Aspherical Optical System
Moon, Jae-Il ; Yoo, Kyung-Sun ; Hyun, Dong-Hoon ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 487~492
DOI : 10.7735/ksmte.2012.21.3.487
In this study we researched a spotlight in LED lighting. Ordinary LED spotlight was manufactured with characterized property of traveling straightness of LED light source, but multiple use of shell type LED, a yellow band has formed caused by light source interference between the LED. Also, there was a high miscellaneous light efficiency with losing light source homogeneity and efficiency due to light source control uneasiness. The study uses aspheric reflector and aspheric lens, so we can control the light source of LED spotlight with effectively and we reached surface light source by using COB/COM for LED module. Furthermore it can change its use by a reduced scale of light system. It has been designed to make its various application from low power consumption of bicycle lamp, up to high power consumption of automobile lamps and lighthouse.
A Study on the Design of a Rotational Force Generator for Molten Metal
Lee, Jun-Ho ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 493~501
DOI : 10.7735/ksmte.2012.21.3.493
A rotational force generator for molten metal is developed using a linear motor design technology. Also, the developed device is applied to reproduce aluminum scraps and easy to control the rotate, stop, and forward and reverse rotation of molten metal. In addition, the developed device improves the melting speed and reproduction rate about 250 (%) and 96-99 (%), respectively, compared to the conventional handmade methods. Because it generates almost no dusts, it can improve working environments in a factory. Also, it has no losses in energy because it directly melts scraps. The device generates small amounts of the loss in refractory materials and aluminum caused by its oxidation because the molten metal is continuously rotated in which the loss and oxidized aluminum are the problems in the conventional melting and holding furnaces. Thus, it is possible to extend the life of furnaces and to produce high quality aluminum products.
Development of a Static Pressure Radial Air Bearing and Estimate of Design Variables
Kim, Ock-Hyun ; Lee, Kyu-Ho ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 502~506
DOI : 10.7735/ksmte.2012.21.3.502
Air bearing is characterized by its extremely low friction and cleanliness such that it is widely used especially for spindles with ultra-high rotational speed at several tens of thousands rpm. This paper contributes to design of a static radial air bearing suggesting numerical analysis to anticipate its performances. The numerical analysis is an iteration method based on finite difference formulation of the Reynolds equation. A prototype air bearing has been designed and manufactured. Its load capacity has been measured and compared with the numerical solutions. The result shows good consistency between the experiment and theory, which informs that the numerical analysis can be used as an useful tool to anticipate the performances. Effects of design variables on the bearing performance have been examined by Taguchi's experimental methods using orthogonal array. Number of holes for supplying pressurized air, clearance between shaft and bearing, the hole diameter and bearing length are chosen for the design variables. The result shows that the clearance and the bearing length are the most influential variables while the others can be considered as almost negligible.
Investigation of Improve to RFID Tag Packaging Reliability
Ban, Chang-Woo ; Jang, Dong-Young ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 507~515
DOI : 10.7735/ksmte.2012.21.3.507
Recently RFID(Radio Frequency Identification) technology advances in wireless communication technologies are bringing new challenges. But RFID tag packaging technology has been lagging compared to the demand, so this technology is being required to improve productivity and reliability. This study is performed on FMEA, reliability at development level and analysis failure mode through environment and mechanical test. Robust design is applied to search the optimized condition of factor and RFID tag packaging should be satisfied with high MTTF.
An Experimental Study for Drawing of Optimal Process Condition in the SLS Process
Bae, Sung-Woo ; Yoo, Seong-Yeon ; Kim, Dong-Soo ;
Journal of the Korean Society of Manufacturing Technology Engineers, volume 21, issue 3, 2012, Pages 516~524
DOI : 10.7735/ksmte.2012.21.3.516
Selective Laser Sintering(SLS) system consists of various element technologies. Main components of the system include a position control system, a speed control system of the roller, and nitrogen atmosphere furtherance for the powdered sintering. Other systems which make the core of the SLS system are build room and the feed room for powder epitaxial, a temperature control system, and a scan path generator for the laser. The powder material for laser sintering is necessary to produce prototypes in Solid Freeform Fabrication(SFF) based on SLS process. This powder material is sintered in powder room using
laser after spreading evenly using roller to reproduce mold via SFF. This study addresses an SFF system by using the SLS process which applies single laser system to enable manufacturing of 3D shape. And to evaluate applicability of the single laser system, experiments were conducted with optimal fabricating process.