• 제목/요약/키워드: 형상기억

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긴장력이 적용된 초탄성 형상기억합금 장수명 댐퍼의 특성 분석 (Characteristic Analysis of Superelastic Shape Memory Alloy Long-Lasting Damper with Pretension)

  • 이헌우;김영찬;허종완
    • 대한토목학회논문집
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    • 제44권1호
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    • pp.11-17
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    • 2024
  • 제진 구조는 댐퍼라는 장치를 구조물에 장착시켜 지진에너지를 소산하는 내진설계이다. 지진피해를 저감하고자 하는 연구가 성행하고 있는 가운데 제진 구조는 댐퍼의 재료, 형상을 변경함으로써 기술을 발전시켜왔다. 하지만 댐퍼의 특성상 에너지를 소산하기 위해 재료에 발생하는 소성변형은 피할 수 없는 한계가 있다. 따라서 본 연구에서는 발생한 변형를 스스로 회복할 수 있는 초탄성 형상기억합금(Superelastic shape memory alloy, SSMA)을 활용하여 반영구적으로 사용할 수 있고 추가적인 긴장력을 적용하여 구조적 성능을 향상한 장수명 댐퍼를 제안하였다. 장수명 댐퍼의 거동 특성 분석을 위해 재료, 와이어 직경, 긴장력 유무의 설계 변수에 따라 유한요소해석을 진행하였고 응답 거동을 도출하여 하중 저항, 에너지 소산, 잔류변위 등의 특성을 분석하여 장수명 댐퍼의 성능적 우수성을 입증하였다.

Vacuum Hot Pressing에 의한 6061Al기지 지적복합재료의 제조 및 기계적 특성 (Process and Mechanical Properties of Smart 6061Al Matrix Composite by Vacuum Hot Pressing)

  • 이준희;;;;박창선;김순국
    • 한국재료학회지
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    • 제7권11호
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    • pp.951-956
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    • 1997
  • Vacuum Hot Pressing을 이용하여 제조한 TiNi형상기억섬유 강화 6061 AI기지 복합재료를 제조하고 미세조직 및 기계적 특성 등을 연구하였다. 제조된 복합재의 항복응력은 예비변형량, 섬유체적율 및 열처리에 따라 증가하였다. 복합재의 지적특성은 예비변형이 가하여진 후 재가열되었을 때 기지 내 TiNi 섬유의 형상기억효과에 의한 압축잔류응력 발생에 기인된다. 미세조직 관찰 섬유와 기지 사이에는 AI$_{3}$Ti및 AI$_{3}$Ni의 금속간화합물층이 관찰되었다. 또한 시험온도 증가와 더불어 TiNi섬유강화된 복합재의 유동강도는 높은 값을 나타내었다.

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형상기억합금 상호작용 에너지의 유한요소 계산 (Finite element calculation of the interaction energy of shape memory alloy)

  • 양승용
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.79-84
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    • 2004
  • Strain energy due to the mechanical interaction between self-accommodation groups of martensitic phase transformation is called interaction energy. Evaluation of the interaction energy should be accurate since the energy appears in constitutive models for predicting the mechanical behavior of shape memory alloy. In this paper, the interaction energy is evaluated in terms of theoretical formulation and explicit finite element calculation. A simple example with two habit plane variants was considered. It was shown that the theoretical formulation assuming elastic interaction between the self-accommodation group and matrix gives larger interaction energy than explicit finite element calculation in which transformation softening is accounted for.

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NITINOL을 이용한 차동식 액츄에이터의 설계에 관한 연구 (A study on the Design of Bidirectional Actuator using NITINOL)

  • 정상화;김현욱;신형성;차경래;신병수
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 춘계학술대회 논문집
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    • pp.670-674
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    • 2002
  • In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

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형상기억입자 강화 복합체의 탄성계수 평가 (Evaluation of Elastic Modulus in a Particulate Reinforced Composite by Shape Memory Effect)

  • 김홍건
    • 대한기계학회논문집A
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    • 제25권1호
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    • pp.25-31
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    • 2001
  • The theoretical modeling to predict the modulus of elasticity by the shape memory effect of dispersed particles in a metal matrix composite was studied. The modeling approach is based on the Eshelbys equivalent inclusion method and Mori-Tanakas mean field theory. The calculation was performed on the TiNi particle dispersed Al metal matrix composites(PDMMC) with varying volume fractions and prestrains of the particle. It was found that the prestrain has no effect on the Yonugs modulus of PDMMC but the volume fraction does affects it. This approach has an advantage of definite control of Youngs modulus in PDMMCs.

형상기억합금 기반 공구클램핑 장치를 위한 자동공구교환 시스템 개발 (Development of Automatic Tool Change System of the SMA-Based Tool Clamping Device)

  • 신우철;노승국;김병섭;박종권
    • 한국생산제조학회지
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    • 제19권5호
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    • pp.710-715
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    • 2010
  • This study developed an automatic tool change system of the SMA-based tool clamping device for applications of micro-machine tools. This paper first describes clamping and unclamping procedures of the automatic tool change system and its basic configuration. Second, it presents fabrication techniques of components, such as a heating/cooling system and a tool loader. Finally, it describes automatic tool change test conducted with a prototype in which the fabrication techniques of components were employed. As the results of the test, times needed for clamping and unclamping operations were estimated to 18(s) and 8(s) respectively. The experimental results confirm that the proposed automatic tool change system can be sucessfully applied to micro-machine tools.

초소형 내시경 작동기의 개발과 제어에 관한 연구 (A Study on Development and Control of Micro Active Catheter Actuator)

  • 이장무;김종현;이상원;박준형
    • 한국정밀공학회지
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    • 제16권2호통권95호
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    • pp.15-22
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    • 1999
  • This paper demonstrates the feasibility of Shape Memory Alloy (SMA) actuators in controlling the motion of micro active catheter. The dynamic behavior of SMA is obtained by several experiments for the design of the controller. With the control parameters obtained in experiments, temperature feedback control algorithm is proposed and realized. The prototype of micro active catheter is fabricated, and its control performance which uses the designed controller is investigated. The results obtained show the potential of the SMA as viable means for actuating the micro active catheter.

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