• 제목/요약/키워드: Design and Fabrication

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Optimum design of stiffened plates for static or dynamic loadings using different ribs

  • Virag, Zoltan;Jarmai, Karoly
    • Structural Engineering and Mechanics
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    • 제74권2호
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    • pp.255-266
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    • 2020
  • The main requirements of modern welded metal structures are the load-carrying capacity (safety), fitness for production, and economy. The primary objective of attaching longitudinal stiffeners is to improve the buckling strength of relatively thin compression panels. This paper gives several comparisons for stiffened plates with different loadings (static, dynamic), different shape of stiffeners (flat, L-shape, trapezoidal), different steel grades, and different welding technologies (SMAW, GMAW, SAW), different costs to show the necessity of a combination of design, fabrication and economic aspects. Safety and fitness for production are guaranteed by fulfilling the design and fabrication constraints. The economy is achieved by minimizing the cost function. It is shown that the optimum sizes depend on the welding technology, the material yield stress, the profile of the stiffeners, the load cycles and the place of the production.

The mechanical design and fabrication of 162.5 MHz buncher for China accelerator driven sub-critical system injector II

  • Niu, Haihua;Li, Youtang;He, Yuan;Zhang, Bin;Huang, Shichun;Yuan, Chenzhang;Jia, Huan;Zhang, Shenghu
    • Nuclear Engineering and Technology
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    • 제49권5호
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    • pp.1071-1078
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    • 2017
  • A buncher is one of the main pieces of equipment in the medium energy beam transport line (MEBT) for China accelerator driven sub-critical system (C-ADS) Injector II. To focus the beam longitudinally and match the beam for the acceptance of the superconducting linac section, two room temperature quarter wave resonator (QWR) bunchers with frequency of 162.5 MHz have been designed as parts of the MEBT. According to the beam transmission matching of the MEBT and the geometric parameters requirements of bunchers, the unique mechanical structure and the main processing technology of buncher cavities and their couplers and tuners are described in this paper. The fabrication of bunchers and their parts have been completed and tested at high power, the test results agree well with the design requirements. These bunchers work well for about two years in Institute of Modern Physics, Chinese Academy of Sciences.

Characterization of Negative Photoresist Processing by Statistical Design of Experiment (DOE)

  • Mun Sei-Young;Kim Gwang-Beom;Soh Dea-Wha;Hong Sang Jeen
    • Journal of information and communication convergence engineering
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    • 제3권4호
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    • pp.191-194
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    • 2005
  • SU-8 is a epoxy based photoresist designed for MEMS applications, where a thick, chemically and thermally stable image are desired. However SU-8 has proven to be very sensitive to variation in processing variables and hence difficult to use in the fabrication of useful structures. In this paper, negative SU-8 photoresist processed has been characterized in terms of delamination, based on a full factorial designed experiment. Employing the design of experiment (DOE), a process parameter is established, and analyzing of full factorial design is generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

3차원 그래픽 설계와 3D 프린팅에 의한 보조기 쾌속조형 제작 방법 연구 (3D printing-based Fabrication of Orthotic Devices Using 3D Computer-Aided Design and Rapid Prototyping)

  • 최봉근;허서윤;손경태;이신영;나대영;이근민
    • 재활복지공학회논문지
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    • 제9권2호
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    • pp.145-151
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    • 2015
  • 본 연구에서는 3D 스캐닝에서 획득한 이미지 정보를 바탕으로 3차원 그래픽 제품설계와 3D 프린팅 기술을 적용한 보조기 제작방법을 제시하였다. 뇌성마비 환자를 대상으로 4가지 종류의 보조기를 기존의 수작업이 아닌 전산화된 작업 기술을 적용하여 제작해봄으로써 방법과 절차에 대한 기준을 마련하고, 이 기술이 임상적으로 사용 가능한지 여부에 대해 확인했다. 보조기 사용 시 환자만족도와 보조기 제작시간, 인장강도 등의 비교를 통하여 정량적, 정성적으로 제작방법의 적용 가능성을 검증한 결과 기존의 열가소성 수지가 표출했던 문제를 보완하고 대체가능한 방법이 될 가능성이 있음을 확인하였다.

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Characterization of Photoresist Processing by Statistical Design of Experiment (DOE)

  • Kim, Gwang-Beom;Park, Jae-Hyun;Soh, Dae-Wha;Hong, Sang-Jeen
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.43-44
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    • 2005
  • SU-8 is a epoxy based photoresist designed for MEMS applications, where a thick, chemically and thermally stable image is desired. But SU-8 has proven to be very sensitive to variation in processing variables and hence difficult to use in the fabrication of useful structures. In this paper, negative SU-8 photoresist processed has been characterized in terms of delamination. Based on a full factorial designed experiment. Employing the design of experiment (DOE), a process parameter is established, and analyzing of full factional design is generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

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The Consequences of Data Fabrication and Falsification among Researchers

  • KANG, Eungoo;HWANG, Hee-Joong
    • 연구윤리
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    • 제1권2호
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    • pp.7-10
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    • 2020
  • Purpose: The experience by a researcher highlighted steps is guided by a specific ethical codes of conduct. The purpose of the current study is to discuss the fabrication and falsification of data as the key ethical misconduct committed by many researchers focus on their causes and impact in the research field. Research design, data and methodology: To obtain suitable textual resource, the current study used content analysis to closely take a look at the fabrication and falsification based on prior research in the realm of publication ethics. As a result, the current authors could collect and understand adequate textual data from appropriate prior resources. Results: The Research misconduct is a common practice in different countries across the world. Based on the findings from this study, data fabrication or falsification have a grievous impact on all the stakeholders of a study. The unethical behavior affects the parties concerned both psychologically and financially. Conclusions: It is, therefore, recommended that researchers should be held accountable. This can be done through different means, including raising awareness of vulnerability to data fabrication and falsification. The government and research institute should also advocate for effective policies guiding research studies across the world.

마이크로 거울의 구동을 위한 저전압 비틀림형 열구동기의 설계 및 제작 (Design and Fabrication of Low-Voltage Twisting-Type Thermal Actuators for Micromirrors)

  • 김동현;박용철;박승호;권오명;최영기;이준식
    • 대한기계학회논문집B
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    • 제33권10호
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    • pp.803-810
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    • 2009
  • Micromirrors have a wide range of applications such as optical switches, laser scanners, and digital projection displays. Due to their low performances and high costs, however, practical applications of micromirrors are quite limited. At present micromirrors demand not only a better design but also a simple fabrication process. In this study a twisting-type micromirror that can be driven by two thermal bimorph actuators bending in opposite directions is designed from electro-thermo-mechanical theories and fabricated through a simple MEMS process. Each actuator consists of $SiO_2$ and gold thin-film layers. Simplified analytical model has been built to optimize the performance of micromirror. Due to unexpected resistance increase of metal film and alignment mismatch during fabrication process, experimental rotation angles of micromirrors are about $11^{\circ}$ at applied voltages less than 0.6V. From numerical simulation and analytical studies, however, the next design can provide rotation angles over $20^{\circ}$ at the same applied voltage.

솔벤트 증기처리 Reflow를 이용한 폴리머 마이크로 렌즈 제작 및 특성고찰 (Fabrication and Characterization of Polymer Microlens using Solvent-vapor-assisted Reflow)

  • 양승우;김신형;김보현;조영학
    • 한국정밀공학회지
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    • 제32권3호
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    • pp.299-305
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    • 2015
  • In this paper, we propose a simple and low-cost fabrication method of polymer microlens using solvent-vapor-assisted reflow (SVAR). Metal molds for replication of polymer were fabricated using micro milling and the cylindrical shape of polymer was imprinted using hot-embossing process. The cylindrical shape of polymer was changed to hemispherical lens shape by SVAR. The characteristics of fabricated microlens were evaluated according to the condition of SVAR such as temperature and time. The focal length of polymer microlens could be controlled more easily in low-temperature and long-time condition than in high-temperature and short-time condition. That is, the level of concentrated light to focal point could be improved through the control of temperature and time. Also, we confirmed that toluene was more appropriate solvent than acetone in fabrication of PMMA polymer microlens using SVAR.

Research on the WIP-based Dispatching Rules for Photolithography Area in Wafer Fabrication Industries

  • Lin, Yu-Hsin;Tsai, Chih-Hung;Lee, Ching-En;Chiu, Chung-Ching
    • International Journal of Quality Innovation
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    • 제8권2호
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    • pp.132-146
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    • 2007
  • Constructing an effective production control policy is the most important issue in wafer fabrication factories. Most of researches focus on the input regulations of wafer fabrication. Although many of these policies have been proven to be effective for wafer fabrication manufacturing, in practical, there is a need to help operators decide which lots should be pulled in the right time and to develop a systematic way to alleviate the long queues at the bottleneck workstation. The purpose of this study is to construct a photolithography workstation dispatching rule (PADR). This dispatching rule considers several characteristics of wafer fabrication and influential factors. Then utilize the weights and threshold values to design a hierarchical priority rule. A simulation model is also constructed to demonstrate the effect of the PADR dispatching rule. The PADR performs better in throughput, yield rate, and mean cycle time than FIFO (First-In-First-Out) and SPT (Shortest Process Time).