• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1229-1230
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• 2012

• Transactions of Materials Processing
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• v.8 no.1
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• pp.38-46
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• 1999

This paper deals with the shape fixability of press formed parts through the use of a V-bending process and a U-bending one. The influence of material properties on the shape fixability in forming processes was investigated. A V-bending process had on optimum ben radius for each combination of parameters which caused maximum shape fixability. In the U-bending process the blank holder force could control the degree of shape fixability. A ha호 blank holding force resulted in a uniform strain distribution and increased shape fixability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.6
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• pp.560-565
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• 2005

This paper deals with the development of manually operated die used for the manufacture of octagonal boxes into two sets of automated die. In particular, theoctagonal boxes are used fur the switch boxes intended fur the cable conduit of buildings or f3r wiring connection. Manufacturing these boxes requires forming the materials using the primary press before they undergo 2nd through 6th processing by the press machine including the four sides of the octagonal outlet box and bending. Such complicated process hikes up labor cost, slows down production, and results in defect rate of $10\%$ or higher; hence the overall rise in manufacturing cost. Moreover, workers avoid this type of work due to the roar and vibration coming from the press and the risk of accident. To eliminate such phenomenon, a CAM die made by integrating five sets of die into one set of die and an automatic conveyor system were developed. As a result, unmanned work was realized with only two units of press and two sets of die; thus solving the problem of work being avoided and saving on manufacturing cost.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.4
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• pp.712-720
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• 1988

This paper describes some development of computer-aided system called "COLD-FORMING" and "DESIGN-DIE". "COLD-FORMING" is designed for the forming sequence and "DESIGN-DIE" for the die design of press forming rotationally symmetric parts. The computer program developed is used in interactive and written in BASIC. Design rules for process planning and die design are formulated from process limitations, plasticity theory and know-how of experience of the field. "COLD-FORMING" capabilities include (1) analysis of forming sequence and recognition of individual operation involved each step, (2) determination of intermediate shape and dimensions, (3) calculation of forming loads to perform each forming operation and (4) graphic out put for the operation sheet. "DESIGN-DIE" capabilities include (1) optimum die design corresponding to the output of "COLD-FORMING" and (2) graphic output for the die design.of "COLD-FORMING" and (2) graphic output for the die design.ie design.

• Composites Research
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• v.27 no.6
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• pp.254-259
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• 2014

In this study, a device and pressure press process that is able to substitute autoclave process is developed. This process complements disadvantages of autoclave process which are long process-time and high production cost. The developed device provides air pressure as well as the vacuum which are greatest feature of autoclave process. The device is sealed using hydraulic pressure to keep the air pressure inside the mold. The transfer of the heat is designed to be direct. The heating and pressure charging time are decreased by reducing the interior space. Tooling cost is reduced dramatically compared to autoclave process. Spring-back phenomenon is measured and compared. The temperatures of several parts of the mold during molding are measured. The fiber volume fraction of the parts molded by autoclave process and by the developed process are compared.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5769-5777
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• 2015

According to the forming or bending deformation in the press die, the thin plate occurs a work-hardening, the sheet hardening and cam unit's deformation causes incomplete forming during the cam molding process by the reacting spring forces. This study treated the input parameters of the stress and strain as given properties and also used Cam forming pressure considering the sheet hardening in the forming process of the aluminum sheet. The Hyperstudy are operated be linked with the Abaqus of the finite element analysis tool and the shape of Cam were carried out with non-linear shape optimization analysis. As a result removing the deformation of plate, the cam shape were optimized under conditions reduced deformation, having a minimum stress range and the minimum deformation. Therefore, a stress-strain curve and a normal distribution of stress-thickness can be obtained and optimization could be obtained for the shape of the stress and strain on the die plate hardened cam considering the thickness and reaction force of gas spring as iteration process.

• Design & Manufacturing
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• v.16 no.4
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• pp.1-6
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• 2022

Fine blanking is a press processing technology that can process most of the product thickness into a smooth surface with a single stroke. In this fine blanking process, shear is an essential step. The punches and dies used in the shear are subjected to impacts of tens to hundreds of gravitational accelerations, depending on the type and thickness of the material. Therefore, among the components of the fine blanking mold (dies), punches and dies are the parts with the shortest lifespan. In the actual production site, various types of tool damage occur such as wear of the tool as well as sudden punch breakage. In this study, machine learning algorithms were used to predict these problems in advance. The dataset used in this paper consisted of the signal of the vibration sensor installed in the tool and the measured burr size (tool wear). Various features were extracted so that artificial intelligence can learn effectively from signals. It was trained with 5 features with excellent distinguishing performance, and the SVM algorithm performance was the best among 33 learning models. As a result of the research, the vibration signal at the time of imminent tool replacement was matched with an accuracy of more than 85%. It is expected that the results of this research will solve problems such as tool damage due to accidental punch breakage at the production site, and increase in maintenance costs due to prediction errors in punch exchange cycles due to wear.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.43-49
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• 2004

With building structures becoming higher and having longer spans, new structural steel with better strength, thicker plate, and performance may be required rather than conventional structural steel. TMC steel is widely used in building structures largely due to its excellent seismic performance, superior weldability, and design strength that is not affected by plate thickness. To make use of TMC steel in pipe structures with large diameter and heavy wall, however, the this study, the degradation of material properties in submerged are welded SM520TMC steel pipes and tubes was evaluated using variable fabrication process and material change. Degradation test results showed that the yield and ultimate strength increased and elongation decreased regardless of the mode of fabrication, i.e., through roll bending or press forming, or steel used, i.e., domestic SM520TMC steel or SM520TMC steel from Japan.

• Archives of design research
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• v.18 no.4 s.62
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• pp.155-164
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• 2005

In contrast with product design field, some designers who work in furniture field tend to do their own studio works as well as typical designing part. Especially in the small furniture studios for the limited quantity batch production, custom made or handmade craft furniture which is finished with high quality, the propensity for their own production is more obvious than in the big furniture companies in this case. In this kind of small-scale furniture studios, they have more chance to create the various formative works and 'curved shape' is one of the most important elements to form creative pieces. Except by caning, it is very difficult to make curved wooden shape because of own characteristic of wood. Therefore, the special techniques of bending wood are essential to formative furniture production and vacuum press system is introduced as a main subject for the bending wood method in this study. Especially for the designers who work as makers as well at the small furniture studios, the value of vacuum press system on efficiency and productivity of work was sought by testing and improving the method of wood bending techniques. According to this practical searching, ideally sufficient condition on vacuum pressing work was founded as a result on this study.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.43-50
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• 2012

Database for the information of the shape accuracy is constructed with the finite element stamping analysis of the center pillar member. Analyses are carried out in order to investigate the effect of tool compensation on the product quality previously performed by an expert in the press shop. The compensation procedure is provided with three sequences for improving shape accuracy of the member by reducing the amount of springback. The analysis result shows that shape inaccuracy in the product is caused by sagging and twisting phenomena from displacement of the section part due to excessive amount of springback. From the database with springback analyses, design modification guidelines are proposed for improving the shape accuracy. The guideline is directly applied to a member with the similar shape and the sound product is obtained successfully reducing the amount of springback.