• 한국융합학회논문지
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• 제10권12호
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• pp.281-286
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• 2019

자동차의 하부를 수리하기 위해서는 차 밑으로 들어가야 된다. 그러나 이 작업은 수리공이 수리하기에 불편하기도 하고 사고를 일으킬 수도 있다. 이러한 난제들을 해결하기 위하여 개발된 장비가 자동차의 리프트이다. 본 연구에서는 세 가지의 자동차의 리프트 Model 1, 2, 3을 설계하였다. 구조용 강의 물성치를 모델들에 적용하고 동일한 조건으로 같은 하중을 가하여 해석을 하였다. Model 2, 3이 Model 1보다 더 적은 구조적 변형을 보였으며 Model 2, 3이 Model 1보다 구조적으로 더 안정적인 것을 나타냈다. 본 연구결과를 토대로 얻은 자동차 리프트 형상에 따른 내구성 해석을 통한 융합 연구에 대한 설계데이터를 활용함으로서 실생활에서의 자동차 수리 기자재 부품에 융합하여 그 미감을 보일 수 있다.

• 대한치과보철학회지
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• 제30권1호
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• pp.65-72
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• 1992

The purpose of this study was to evaluate the flexure stregth of posterior 4-unit acrylic resin bridge with different pontic designs : 1) Conventional pontic 2) Hygienic pontic and 3) Modified hygienic pontic. All specimens were made of self-curing acrylic resin for provisional restorations. Self-curing acrylic resin was filled in a silicone mold by the drop-on technique ; and was polymerized in a pressure spot under 20 psi pressure. The test specimens which were simply shaped posterior 4-unit bridge were 38mm ion 4mm wide, and 35mm thick(connector : 3mm thick). Each specimen was subjected to an increasing load of Instron machine with its tip centered on the specimen at 90-degree angle, and the machine was operated with its load cell of 50kg and its crosshead speed, 2mm/minute : and then the load values at the moment of the fracture of them were recorded. This study was also performed to analyze their stress distributions by the finite element method. The obtained results were as follows : 1. Flexure strength of the hygienic pontic(9.78kg) and the modified hygienic pontic(10.17kg) was higher than that of conventional pontic(6.96kg). But no significant difference was found between the hygienci pontic and the. modified hygienic pontic. The above statistic values were appraised by ANOVA and Duncan's multiple range test 2. Stress was concentrated on the middle portion in every group : and the stress of conventional pontic was found the greatest of all pontic designs.

• 한국의류산업학회지
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• 제17권3호
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• pp.429-439
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• 2015

This study develops a new brassiere for new silver women. A new brassiere design was developed for the silver generation based on apreliminary survey; subsequently, a wire and no-wire type of brassier were developed after a second fitting evaluation. The results were as follows. First, in terms of brassiere design, the cup shape was designed as mold type full cup, shoulder straps were designed as camisole type with cups, bias tape was designed for body correction in the side line and mash tape was designed for easy movement below the cups. On the other side ofthe cup shape was a pocketdesigned on a support pad forthe wire type and a support panel to serve as a wire in the no-wire type brassiere. Second, brassiere patterns were designed by referencing the educational H pattern. Thetotal length was elongated by 5cmto reduce pressure when wearing a brassiere and the height of the front center increased by 8cm for the stability of the front center of the brassiere. In addition, the side line was moved back by 3cm and the width of the brassiere wings was designed widely at 10.5cm. Third, a wearing test was conducted for the wire type and the no-wire type brassiere with comparison products, using a 7-point Likert scale. Appearance results and movement tests for the wire and no-wire type showed a higher score than comparison products.

• 한국정밀공학회지
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• 제29권11호
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• pp.1256-1263
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• 2012

The present study covers the ultrasonic patterning process to replicate micro-patterns on a polymer substrate. The ultrasonic patterning process uses ultrasonic waves to generate frictional heat between an ultrasonic horn and the polymer substrate, from which the surface region of the polymer substrate is softened sufficiently for the replication of micro-patterns. The ultrasonic patterning process can divided into two categories according to the direction of vibration transmission: direct patterning and indirect patterning. The direct patterning uses a patterned horn, and the ultrasonic vibration is transferred directly from the patterned horn to the substrate. On the contrary, the indirect patterning process uses a plain horn, and the micro-patterns are engraved on a mold that is located below the substrate. Thus, the micro-patterns are replicated as an indirect manner. In this study, these direct and indirect patterning processes are compared in terms of the replication characteristics. Additionally, the possibility of double-side patterning is also discussed in comparison with the conventional single-side patterning process.

• 소성∙가공
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• 제29권4호
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• pp.194-202
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• 2020

In this paper, experimental and numerical study on a combined sheet metal forming and plate forging of a seal part of a passenger car's hub bearing is conducted to develop the new process of which target is to remove machining process by plate forging and to achieve near-net shape manufacturing. The previous process of a sheet metal forming inevitably needed a machining process for making stepped sheet after conventional sheet metal forming in a progressive way. The stepped sheet is intended to be formed by plate forging in this study. Through the systematic way of developing the combined forming process using solid elements based-elastoplastic finite element method (FEM), several conceptual designs are made and an optimized process design in terms of geometric dimensioning and tolerance of straightness of the thin part is found, which is exposed to bending in metal forming of axisymmetric part. The predicted straightness measured by the slope angle of the tilted thin region is compared with the experimental straightness, showing that they are in a good agreement with each other. Through this study, a systematic approach to optimal process design, based on elastoplastic FEM with solid elements, is established, which will contribute to innovating the conventional small-scaled sheet metal forming processes which can be dealt with by solid elements.

• 방사성폐기물학회지
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• 제8권1호
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• pp.85-89
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• 2010

사용후핵연료 파이로프로세싱 공정 생성물인 우라늄 전착물을 잉곳 형태로 주조하는 공정이 있다. 이 논문에서는 실험실 규모의 우라늄 전착물 잉곳 주조 장치에 대한 설계 개념을 소개하고, 이에 따라 제작된 장치의 성능 시험 결과 및 우라늄을 사용한 잉곳 주조 시험 결과를 소개한다. 이 장치는 도가니를 경동시켜 우라늄 용탕을 주형에 주입하여 우라늄 잉곳을 제조하며, 우라늄 전착물을 연속으로 주입할 수 있는 컵 형태의 원료 장입장치를 장착하였다. 이러한 장치를 사용하면 우라늄 전착물의 잉곳 생산성을 높일 수 있다. 실험 결과 우라늄 원료를 장입하여 주조한 결과 수축공이 적은 양호한 주물을 제조하는데 성공하였으며, 이러한 실험실 규모의 장치를 개발한 경험을 활용하여 공학규모의 장치를 설계하는데 활용하였다.

• 구강회복응용과학지
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• 제32권3호
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• pp.246-254
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• 2016

Direct metal laser sintering (DMLS) 방식은 3D 프린팅 중 한 방식으로, 재료를 쌓아가면서 레이저를 이용하여 선택적으로 sintering하는 방식이다. 이는 주조 방식에서 문제되는 결손과 뒤틀림을 방지할 수 있으며 절삭 가공 방식으로 제작하기 어려운 복잡한 구조물을 제작할 수 있다. 본 증례들은 DMLS 방식을 이용하여 지대치 간 길이가 긴 고정성 보철물, 포스트 등 다양한 고정성 보철물을 제작하여 수복하였고, 주기적인 관찰 결과 심미적, 기능적으로 만족할만한 결과를 얻었기에 이를 보고하는 바이다.

• 한국기계가공학회지
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• 제16권6호
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• pp.117-124
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• 2017

In this study, we investigated the optimization of process conditions by using the Six Sigma process, design of experiment (DOE) method and response surface method (RSM) to resolve dimensional deviation and appearance problems arising from the shortened process time of the mobile phone rear cover. The analysis of the trivial many was performed by 2-sample T-test and cooling time, and mold temperature and packing pressure were selected as the vital fews affecting the overall width of the product. The optimal conditions of the process were then studied using the DOE and the RSM. We analyzed the improvement effects by applying the selected optimal conditions to the production process and the results showed that the difference between the mean value and target value of the overall width stood at 0.01 mm, an improvement of 88.89% compared to current process that fell within the range of standard dimension. The short-term process capability stood at $4.77{\sigma}$, which implied an excellent technology level despite a decrease by $0.22{\sigma}$ compared to the current process. The difference in process capability decreased by $2.44{\sigma}$ to $0.41{\sigma}$, showing a significant improvement in management capability. Ultimately, the process time of the product was shortened from 18.3 seconds in the current process to 13.65 seconds, resulting in a 34.07% improvement in production yield.

• 한국기계가공학회지
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• 제20권5호
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• pp.76-84
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• 2021

In this study, an optimal stiffness model of the C-frame, which was supporting the mold and tool load, was proposed to obtain quality self-piercing riveting (SPR) joining. First, the load path acting on the C-frame structure was identified using topology optimization. Then, a final suggested model was proposed based on the load path results. Stiffness and strength analyses were performed for a rivet pressing force of 7.3 [t] to compare the design performance of the final proposed model with that of the initial model. Moreover, to examine the reliability of continuous and repeated processes, vibration analysis was performed and the dynamic stiffness of the final proposed model was reviewed. Additionally, fatigue analysis was performed to ascertain the fatigue characteristics due to simple repetitive loading. Finally, stiffness test was performed for the final proposed model to verify the analysis results. The obtained results differed from the analysis result by 2.9%. Consequently, the performance of the final proposed model was superior to that of the initial model with respect to not only the SPR fastening quality but also the reliability of continuous and repetitive processes.

• 한국융합학회논문지
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• 제10권7호
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• pp.149-154
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• 2019

본 논문은 오프로드용 SUV 자동차의 프론트 언더커버에 대한 구조해석을 통하여 내구성을 연구하고자 한다. 실제 사용되는 차체 하부 보호용 언더커버의 형상과 비슷한 3종류의 모델들을 해석하여 어떤 모델이 구조적으로 가장 좋은 것인지 고찰하였다. 언더커버의 모델들은 CATIA 프로그램을 통하여 Model A, B, C 3종류로 설계하였고 ANSYS 프로그램을 이용하여 해석을 하였다. 해석 결과들을 통하여 세 모델들 중에서 Model B가 최대 등가 응력이 가장 작고 피로 수명도 길어서 내구성이 가장 좋은 것으로 나타났다. 본 연구결과를 토대로 얻은 언더커버의 내구성 있는 설계데이터를 활용함으로서 실생활에서의 기계나 구조물에 융합하여 그 미적 감각을 나타낼 수 있다.