Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of The Korean Society of Manufacturing Technology Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Manufacturing Technology Engineers
Editor in Chief :
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
Selecting the target year
Fabrication and Optical Characterization of Porous Silicon Nanowires
Kim, Jungkil ; Choi, Suk-Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 855~859
DOI : 10.7735/ksmte.2012.21.6.855
Silicon nanowires (SiNWs) were fabricated by a metal-assisted chemical etching of Si and the porous structure on their surfaces was controlled by changing the volume ratio of the etching solution composed of hydrofluoric acid, hydrogen peroxide, and deionized water. The concentration of hydrogen peroxide as the oxidant was varied for controlling the porosity of SiNWs. The optical properties of porous SiNWs were unique and very different from those of single-crystalline Si, as characterized by measuring their photoluminescence and Raman spectra for different porosities.
Effect of wear of Contact Tips to Welding Consumable for Gas Metal Arc Welding
Kim, In-Gyu ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 860~864
DOI : 10.7735/ksmte.2012.21.6.860
The contact tip is higher the wear of resistance and the longer life are demanded to GMA welding process. In this study, four different contact tips with three different compositions by two wires were evaluated their wear resistance by measuring in every one hour the area of enlarged hole at the exit side during actual wleding. Experimental results clearly showed that the Cr-containing tips strengthened by precipitation hardening have much better resistance to wear than those made by work hardening. In addition, flux cored wire is excellent abrasion resistance test results showed. Based on these results, the domestic industry, the life of the contact tip to know will be used as basic data.
Collapse Characteristics of CFRP hat Shaped Structural Member with Various Orientation Angle for a Use of Lightweight
Hwang, Woochae ; Yang, Yongjun ; Yang, Inyoung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 865~870
DOI : 10.7735/ksmte.2012.21.6.865
CFRP of the advanced composite materials as structure materials for vehicles has a widely application in lightweight structural materials of air planes, ships and automobiles because of high strength and stiffness compared with conventional materials. This study is to investigate the energy absorption characteristics and collapse mode of CFRP single and double hat shaped structural member under the axial static collapse test. The CFRP single and double hat shaped structural members stacked at different angles (
where the direction on
coincides with the axis of the member). The axial static collapse tests were carried out for each member. Collapse mode and energy absorption characteristics of the each member were analyzed.
A Study on Surface Integrity in Hard Turning
Lee, Han Gyo ; Shin, Hyung Gon ; Yoo, Seung Hyeon ; Kim, Tae Young ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 871~877
DOI : 10.7735/ksmte.2012.21.6.871
New materials widely used for automobile related industry, aircraft, space development area are mostly high hardness materials. The hardness value of some hardened materials is over HRC45 and machining of this hardened materials is called as hard turning. Hard turning has its advantage on processing flexibility, cycle time and tool cost reduction. Also this process obtains high efficiency in processing and precise surface roughness through application of the CBN tools. In hard turning process with CBN tool, surface integrity is the important factor for considering the design of machine part and component under high stress and load conditions. A purpose of this study is to analyze optimal condition in hard turning process of AISI 52100 steel (HRC62) with high CBN and low CBN on turning characteristics, tool wear mechanism comparison and surface integrity.
Anti-Sway Tracking Control of Container Cranes with Friction Compensation
Baek, Woon-Bo ; Shin, Jin-Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 878~884
DOI : 10.7735/ksmte.2012.21.6.878
In this paper, we consider the sway suppression control problem for container cranes with the frictions between the trolley and the rail. If the friction effects in the system can be modelled, there is an improved potential to design controllers that can cancel the effects. The proposed control improves the trolley positioning and sway suppressing against various frictions. The proposed synthesis combines a variable structure control and the adaptive control to cope with various frictions including the unknown constants. First, the variable structure control with the simple switching action is designed, which is based on a class of feedback lineariztion methods for the fast stabilization of the under-actuated sway dynamics of container. Second, the adaptive control with a parameter estimation is designed, which is based on Lyapunov stability methods for suppressing the oscillation of the trolley travelling, especially due to Coulomb friction in the vicinity of the target position. The asymptotic stability of the overall closed-loop system is assured irrespective of variations of rope length. Simulation are shown under initial sway, external wind disturbances, and various frictions.
Structural Analysis of Booms and Basket in the Multi-aerial Platform
So, Soo-Hyun ; Kang, Sung-Soo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 885~891
DOI : 10.7735/ksmte.2012.21.6.885
In this study, some structural analysis using 3D CAD data, material properties, load conditions and boundary conditions are carried out to evaluate structural stability of the multi-aerial platform for high-rise fire fighting and rescue. We conduct structural analysis for the upper structures such as turn table, booms and basket, by using a universal structural analysis program NASTRAN. As the results, there is local stress exceeding the yield strength, but it is able to relax stress concentration in a way such as changing thickness of the structure or making larger inertia moment in cross section of booms.
Strength Evaluation on CFRP Hat-shaped Sectional Members According to Changes in Temperature Under Hygrothermal Environment
Yang, Yongjun ; Kook, Hyun ; Yang, Inyoung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 892~896
DOI : 10.7735/ksmte.2012.21.6.892
CFRP composites with light weight, high strength, and high elasticity by comparing with metal are widely used rather than previous steel plates. However, CFRP composite material has the weakness at hydrothermal and collapsed impact environment. Especially, moisture absorption into composite material can change molecule arrangement and chemical properties under hydrothermal environment. And static collapse experiment is the research in the differences of absorbed energy and deformation mode between moisture and non-moisture absorbed specimens. This study is compared and analyzed on the progress change of moisture absorption ratio after setting up the temperatures of 60 and 80 degrees C in order to comprehend how the change in the temperature influences on moisture absorption status inside CFRP composite materials.
Durability Performance Analysis of a Differential Gear for a Low Speed Vehicles
Cheon, Jong-Pil ; Pyoun, Young-Sik ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 897~902
DOI : 10.7735/ksmte.2012.21.6.897
Low speed vehicle(LSV), golf carts have unique requirements to differential gear design. For double axle torque LSV differential loading conditions were determined with the help of analytical model and ANSYS finite element analysis. With stress safety factor 3.15, fatigue safety factor 1.08 and fatigue life 106 cycle ring gear teeth strength analysis is performed and structure design optimized. This allows reducing overall cost of differential unit.
A Study on the Characteristics of Temperature Distribution according to Material and Position of Filter in a Diesel Particulate Filter
Kim, Gyu-Sung ; Park, Sung-Cheon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 903~909
DOI : 10.7735/ksmte.2012.21.6.903
This study analyzed the temperature distribution in DPF with five partitioned electric heaters. The temperature distribution in DPF is an important design factor for regeneration and durability of filter. The design Factors that influence the temperature distribution in DPF there are several. In this study, the characteristics of temperature distribution in DPF were analyzed according to the following changes. First, the thermal conductivity of the filter was analyzed about effect on the durability of the filter. Second, the length from exhaust manifold to inlet of DPF was analyzed about effect on the temperature distribution in DPF. The boundary conditions of analysis has been verified with comparison to the results of existing experimental study and the numerical analysis. Based on the identified boundary condition, on assuming the condition of the actual driving, the temperature distribution in DPF was analyzed according to material properties of filter and the position of DPF.
A Study on Indications in Radiographic Tests in Welding Specimens According to Shielded Amounts of ATOS 80 High-strength Steel
Baek, Jung-Hwan ; Choi, Byung-Ky ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 910~914
DOI : 10.7735/ksmte.2012.21.6.910
In constructing all kinds of equipment and steel structures, discontinuous areas such as weld defects formed in a welded structure tend to generate cracks that will result in damage. In this study, ATOS high-strength steel welding becomes important in butt welding where the tensile strength of the steel is over 80kg/
. Structural discontinuities such as joints are more susceptible cracks in part due to their repeated loading and fatigue crack growth. The quality of parts produced depend or the shielded amounts of steel and on the skill of the welders in making strong welds. It is true that there are many factors that can be used to generate a lot of research in this area. However geometry and load conditions due to the combined effects with many issues could be solved through this study. Butt welding material at a plate thickness of 12t in ATOS 80 high-strength steel with a 4 pass, 20l/min, 24V/200A welder is good at making specimens with the quality shown in radiographic testing.
A Study on the Radiograph Inspection of Specimen in Welding Pass Using ATOS 80 High-strength Steel
Baek, Jung-Hwan ; Choi, Byung-Ky ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 915~919
DOI : 10.7735/ksmte.2012.21.6.915
In constructing all kinds of equipment and steel structure, parts with discontinuities such as weld defects formed in the welded structure can generate fatigue cracks that results in damage or accidents. In this study, weld zones are investigated with X-rays and the latent images are put on film. Weld zone defects can be verified by developing the film. As weld defects are investigated by radiographic testing and correlated with the welding condition, more appropriate welding conditions can be found. According to the result of X-ray radiographic inspection of butt welding ATOS 80 high-strength steel with a thickness of 12mm, the best conditions for welding without creating weld defects are 4 weld-passes, a protective gas of 20%
and 80% Ar, a protective gas flow of 20L/min, a welding current of 200A, an arc voltage of 24V, a welding speed of 14.4cm/min, a welding rod angle of
, a welding gap of 5 mm with a ceramic base, and sand pre-heating to
Celsius prior to welding.
A Study on the Structural Design of Effective Composite Joint and Light Weight in Body Floor
Kim, Hong Gun ; Oh, Sang Yeob ; Kim, Kwang Choul ; Kim, Hyun Woo ; Kwac, Lee Ku ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 920~925
DOI : 10.7735/ksmte.2012.21.6.920
A study of vehicle weight lightening has been progressed to reduce the fuel consumption. In this paper, the body floor in an EV (Electric Vehicle) bus has been applied by composites as CFRP and GFRP. In order to analyse a various reliability and safety, an experiment and FEM analysis was carried out to obtain weight lightening. Especially, the joint. An effective design is obtained through an experiment as well as FEM analysis. Results of stress analysis of GFRP material showed twice as much displacement than those of CFRP material. Among three kinds of joint methods, the bond joint method is occurred to a substantial shape change in the body and floor. It is found that the rivet joints are fairly suitable for stress sustaining capability.
The Research on Development and Performance of the Rotary bar Cutting tool
Seo, Jeong-Hwan ; Yang, Hae-Jeong ; Kim, Kwang ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 926~931
DOI : 10.7735/ksmte.2012.21.6.926
Rotary bar was cutting tool being in use for deburring scale after welding metal and for eliminating sharp edges. It was necessary to develop exclusive 6-axis machine being possible to process machining continuously for making an cutting edge of rotary bar and to revise easily machining program. This study aimed at the structural analysis of strength according to the configuration of new made 6-axis machine and at the machining accuracy and durability of rotary bar. As a result of test, the runout of new rotary bar manufactured out of 6-axis machine was decreased from 0.385 mm to 0.027mm extensively than old one. And good cutting ability and durability was obtained equal quality compared with imported products.
A Study on the Mechanical Properties of the Friction Welding with Solid Shaft of SM45C
Koo, Keon Seop ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 932~937
DOI : 10.7735/ksmte.2012.21.6.932
In the presented study, SM45C carbon steel parts were joined by friction welding. The welding process was carried out under optimized conditions using statistical approach. The study of SM45C is conducted with various combinations of process parameters. Parameter optimization, microstructure and mechanical property correlation are the major contribution of the study. The welded joints were produced by varying spindle revolution speed, friction pressure, upset pressure and burn-off length. Tension tests were applied to welded parts to obtain the strength of the joints. Fracturs properties were additionally obtained experimentally under fluctuated tensile loads. Microstructures using microphotographs were examined in the weld interface and weld region and heat affected zone and base metal and flash zone of welded parts. Finally, Hardness variations in welding zone and base metal were also obtained. Through these tests, the optimum conditions of parameters for
SM45C in friction welding were obtained when the friction spindle revolution was 1,950 rpm, the friction pressures was 30 MPs, upset pressures was 50 MPs.
A Study on Characteristic of Residual Stresses in a wind Tower Using the Tandem Circumferential Welding Process
Kim, Ji Sun ; Kim, In Ju ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 938~945
DOI : 10.7735/ksmte.2012.21.6.938
This research proposes FEM analysis for Tandem welding process used in wind tower and predicts optimal welding process to improve the stability of welded structures. Three dimensional elasto-plastic analyses are employed to evaluate thermo-mechanical behavior of residual stress and deformation during Tandem welding for different distance between two touches. To confirm the thermal distribution, Goldak`s ellipse heat source model and the real size wind tower pipe model are utilized. Four different analyses are being performed, where in each case the distance between two electrode torches is being changed and residual stress and welding deformation are predicted. Depending on base material state, each case is divided into: Liquid (100mm), Austenite+Liquid (200mm), Austenite+Cementite (400mm), Pearlite+Cementite (800mm).
A Study on Development of High Efficiency Toilets with VOF Numerical Analysis
An, Il Yong ; Lee, Young Lim ; Jo, Woo Suck ; Kim, Jin Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 946~953
DOI : 10.7735/ksmte.2012.21.6.946
When water shortage has been getting worse recently, toilet water-saving is one of the most effective way to solve the water shortage. Therefore, in this study, toilet flushing performance was investigated with VOF(Volume Of Fluid) model to obtain the basic design data for the development of high-efficiency toilets. The result showed that the shorter trapway, the longer the flushing duration time. However, the shorter trapway is found to have disadvantage in exhausting dirt due to relatively weak siphon and higher curvature. Since the remaining water in a trapway appears to help siphon, it is also an important factor in developing high-efficiency toilets. Although higher water level in the water tank shows better performance in flushing, lower water level is preferred to save water. Too low water level may cause dirt to clog the trapway due to relatively weak siphon.
Approximate Multi-Objective Optimization of Robot Casting Considering Deflection and Weight
Choi, Ha-Young ; Lee, Jongsoo ; Park, Juno ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 954~960
DOI : 10.7735/ksmte.2012.21.6.954
Nowadays, rapidly changing and unstable global economic environments request a lot of roles to engineers. In this situation, product should be designed to make more profit by cost down and to satisfy distinguished performance comparing to other competitive ones. In this research, the optimization design of the industrial robot casting will be done. The weight and deflection have to be reduced as objective functions and stress has to be constrained under some constant value. To reduce time cost, CCD (Central Composite Design) will be used to make experimental design. And RSM (Response Surface Methodology) will be taken to make regression model for objective functions and constraint function. Finally, optimization will be done with Genetic Algorithm. In this problem, the objective functions are multiple, so NSGA-II which is brilliant and efficient for such a problem will be used. For the solution quality check, the diversity between Pareto solutions will be also checked.
Design of Air-Conditioner Frame Structure Using TRIZ Based Contradiction Analysis
Choi, Ha-Young ; Jeong, Yiemoon ; Lee, Jongsoo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 961~967
DOI : 10.7735/ksmte.2012.21.6.961
The metal is frequently used in the air-conditioner frame, which must have the durability from the various external environments, but has difficulties in being manufactured for many complex shapes. On the other hand, the plastic, used as a material of injection molding, enables the realization of various shapes and the mass-production of complex ones and leads low production cost. As the air-conditioner frame becomes increasingly complex and detailed, the plastic material is highlighted as an alternative for the frame. But the product molded by plastic with a complex shape might have a noise problem. Therefore this study attempts to design the product through TRIZ in order to reduce the noise of the air-conditioner with the frame of plastic material.
A Study on the Antiabrasion of the Aircraft Carbon Disk Brake
Lee, Jang-Hyun ; Yum, Hyun-Ho ; Hong, Min-Sung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 968~975
DOI : 10.7735/ksmte.2012.21.6.968
ABS(Anti-skid Brake System) had been developed on purpose of most effect at breaking in limited runway. An aircraft has a large amount of kinetic energy on landing. When the brakes are applied, the kinetic energy of the aircraft is dissipated as heat energy in the brake disks between the tire and the ground. The optimum value of the slip during braking is the value at the maximum coefficient of friction. An anti-skid system should maintain the brake torque at a level corresponding to this optimum value of slip. This system is electric control system for brake control valve at effective control to prevent slip and wheel speed or speed ratio. In this study we measured the thickness of the carbon disk before and after to find its wear and it shows that carbon disk brake has higher stiffness and strength than metal disk at high temperature. In addition, thermal structural stability and appropriate frictional coefficient of the carbon disk brake prove its possible substitution of metal disk brake.
A Study on the Physical Property of Epoxy Resin Due to After-Curing Condition
Han, Jeong-Young ; Kim, Myung-Hun ; Kang, Sung-Soo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 976~981
DOI : 10.7735/ksmte.2012.21.6.976
In this study, hardness, microstructure and temperature of glass transition are measured respectively by using SEM (Scanning electron microscope) and DSC (Differential scanning calorimeter) to analyze the effects on material properties by after-curing in the epoxy resin. As the result of hardness test according to the after-curing conditions, the higher the temperature of after-curing, hardness and heat resistance are, the higher hardness is. As a result of microstructure for each specimen by SEM, it could be confirmed that the specimen with after-curing has more dense fracture surface. It is also found that temperatures of glass transitions by DSC are comparatively higher in the specimens with after-curing, and the differences between after-curing conditions are negligible.
A Study on Machinability Evaluation of Inconel 718 in Flat End Milling
Jeong, Jihoon ; Kwon, Haewoong ; Koo, Joonyoung ; Kim, Pyeongho ; Kim, Jeongsuk ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 982~987
DOI : 10.7735/ksmte.2012.21.6.982
Inconel 718 alloy has been widely used in the aerospace, heavy industry and electronic industry. However, the machinability of this alloy is very poor, which is attributed to their inherent high strength that is maintained at elevated temperatures. The tool life is dominant problem in machining difficult-to-cut materials, so it is necessary to select the efficient cutting conditions for the improvement of tool life. In this study, the cutting force, tool wear and surface roughness are investigated in end milling machining under various cutting conditions. By this experiment, the efficient machining condition of this alloy is suggested to adopt in various industries.
Characteristics of Surface Hardening of Nd:YAG Laser According to Temperature Changes of SM45C
Lee, Ka-Ram ; Yang, Yun-Seok ; Hwang, Chan-Youn ; Yoo, Young-Tae ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 988~997
DOI : 10.7735/ksmte.2012.21.6.988
Laser surface hardening is one of core technologies to enhance various characteristics such as the strength, hardness, toughness, abrasion resistance, and fatigue resistance for the mold material. This paper focuses on testing characteristics of the laser heat treatment according to the preheating parameters in case of the SM45C medium carbon steel. In this paper, we assume that the power and travel speed of the laser are 1,800W and 0.5m/min, respectively, and the range of the preheating temperature is
. From the result of the test, we observed that the hardness width and depth are enhanced as the temperature is increased. Also, the best average hardness was 751.7Hv for the temperature of
A Study on the Behavior of Bubbles Trapped in the In-Mold Coating Process
NguyenThi, Phuong ; Kwon, Arim ; Yoo, Yeong-Eun ; Yoon, Jae Sung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 998~1002
DOI : 10.7735/ksmte.2012.21.6.998
This paper investigates the behavior of bubbles trapped in the in-mold coating (IMC) process. Silicon oil with different viscosity, 100, 150, 200, 300 and 400cps, was selected instead of the coating materials. To observe the flow front inside, a special mold was designed, where front plate was made of transparent material (acrylate). The overall size of front plate was
. Mold gate location can be changed from up to down. Four heaters were used to investigate the effectiveness of temperature. The results show that silicon viscosity, mold gate location and mold temperature play an important role on the appearance of bubbles trapped in IMC process.
Characterization of Fiber Direction Influence in CFRP Composites Using Advanced NDE Techniques
Im, Kwang-Hee ; Jang, Ju-Hwan ; Back, Chong-Gui ; Jeong, Ok-Su ; Hsu, David K. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 1003~1007
DOI : 10.7735/ksmte.2012.21.6.1003
A nondestructive technique would be very useful. Advanced NDE T-ray (terahertz ray) techniques of technology and instrumentation has provided a probing field on the electromagnetic spectrum. However, the T-ray is limited in order to penetrate a conducting material to some degree. Here, the T-ray would not go through easily the CFRP composite laminates since carbon fibers are electrically conducting while the epoxy matrix is not. So, investigation of terahertz time domain spectroscopy (THz TDS) was made and reflection and transmission configurations were studied for a 48-ply thermoplastic PPS(poly-phenylene sulfide)-based CFRP solid laminate. It is found that the electrical conductivity of CFRP composites depends on the direction of unidirectional fibers.
Determination of Thermal Contact Conductance of an Injection Mold Assembly for the Prediction of Mold Surface Temperature
Lee, Ki-Yeon ; Kim, Kyeong-Min ; Park, Keun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 1008~1012
DOI : 10.7735/ksmte.2012.21.6.1008
Injection molds are fabricated by assembling a number of plates in which mold core and cavity components are inserted. The assembled structure causes a number of contact interfaces between each component where the heat transfer is affected by the thermal contact resistance. However, the mold assembly has been treated as a one body in numerical analyses of injection molding, which has a limitation in predicting the mold temperature distribution during the molding cycle. In this study, a numerical approach that considers the thermal contact effect is proposed to predict the heat transfer characteristics of an injection mold assembly. To find the thermal contact conductance between the mold core and plate, a number of finite element (FE) simulations were performed with the design of experiment (DOE) and statistical analysis. Thus, the heat transfer analyses using the obtained conductance values can provide more reliable results than conventional one-body simulations.
Nondestructive Evaluation of the Defects in Composite-sintered Bushes Using Ultrasonics
Im, Kwang-Hee ; Kim, Ki-Youl ; Shin, Ki-Taek ; Lee, Han-Hee ; Jung, Il-Woong ; Kang, To ; Cho, Hyun-Joon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 1013~1017
DOI : 10.7735/ksmte.2012.21.6.1013
Advanced composite-sintered bushings are widely utilized in the areas of excavators and injection molding machines as a journal bearing. Since the bearings are mainly used under high loads, service life should be long and the stored oil of inner bushings has to be continually fed into the bearing. The composite-sintered bushings are consisted of the two different materials; outer steel materials and inner porous sintered materials respectively. High temperature diffusion bonding has been applied for holding the both materials of the bushing together. Therefore, it is very important that the bonding reliability has to be assured and evaluated in manufacturing process. Finite element method (FEM) is performed in order to evaluate the minimum allowable flaw sizes that are possibly generated in the composite-sintered bushings. Additionally, the composite-sintered bushings were undergone ultrasonic C-scan tests to find out the size of inherent flaws through artificially simulated UT signal analysis.
Strength and Efficiency during Lap Joining Molding of GMT-sheet
Kim, Jin-Woo ; Kim, Hyoung-Seok ; Kim, Tae-Ik ; Lee, Dong-Gi ; Sim, Jae-Ki ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 6, 2012, Pages 1018~1023
DOI : 10.7735/ksmte.2012.21.6.1018
In order to substitute and recycle the existing automobile parts for GMT-sheet, researches on the effects of GMT-sheet on the establishment of precise joining strength, joining condition that are lap length of joining part, compression ratio, and closure speed must be carried out but until now. Besides, many researches on adhesion joint had been conducted until now but no systematic research on press lap joint of GMT-sheet has been implemented until recently and the reliability of joining strength is not yet established. In press lap joining molding of GMT-sheet, tensile stress and lap joining connection efficiency was increased according to the increase of lap length L. However, as the increase of compression ratio and fiber content ratio per unit area was higher in tensile test, it has caused the deterioration of lap joining efficiency after joining molding of GMT-sheet. Clarify joining strength and lap joining efficiency during high temperature compression press lap joining molding of GMT-sheet and research data regarding to the lap length of joining part was presented. The purpose of this study is to contribute to the substitution of existing products as well as usage development in non-automobile field and also to find out precise dynamic characteristics as designing data of structures.