• 제목/요약/키워드: Invariant of Principal Stretches

검색결과 3건 처리시간 0.016초

초탄성고무 물성평가용 미소압입시험법 개발 및 검증 (Development and Verification of Micro-indentation Technique for Material Property Evaluation of Hyper-elastic Rubber)

  • 이형일;이진행
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.132-137
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    • 2004
  • In this work, effects of hyper-elastic rubber material properties on the indentation load-deflection curve and subindenter deformation are first examined via [mite element (FE) analyses. An optimal data acquisition spot is selected, which features maximum strain energy density and negligible frictional effect. We then contrive two normalized functions. which map an indentation load vs. deflection curve into a strain energy density vs. first invariant curve. From the strain energy density vs. first invariant curve, we can extract the rubber material properties. This new spherical indentation approach produces the rubber material properties in a manner more effective than the common uniaxial tensile/compression tests. The indentation approach successfully measures the rubber material properties and the corresponding nominal stress.strain curve with an average error less than 3%.

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초탄성고무 물성평가용 미소압입시험기의 소프트웨어 및 하드웨어 개발 (Software and Hardware Development of Micro-indenter for Material Property Evaluation of Hyper-Elastic Rubber)

  • 이형일;김동욱;이진행;남승훈
    • 대한기계학회논문집A
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    • 제28권6호
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    • pp.816-825
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    • 2004
  • In this work, effects of hyper-elastic rubber material properties on the indentation load-deflection curve and subindenter deformation are examined via finite element (FE) analyses. An optimal location for data analysis is selected, which features maximum strain energy density and negligible frictional effect. We then contrive two normalized functions, which map an indentation load vs. deflection curve into a strain energy density vs. first invariant curve. From the strain energy density vs. first invariant curve, we can extract the rubber material properties. This new spherical indentation approach produces the rubber material properties in a manner more effective than the common uniaxial tensile/com-pression tests. The indentation approach successfully measures the rubber material properties and the corresponding nominal stress-strain curve with an average error less than 3%.

초탄성 고무 물성평가를 위한 구형 압입시험의 수치접근법 (Numerical Approach Technique of Spherical Indentation for Material Property Evaluation of Hyper-elastic Rubber)

  • 이형일;이진행;김동욱
    • Elastomers and Composites
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    • 제39권1호
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    • pp.23-35
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    • 2004
  • 본 연구에서는 먼저 유한요소해석을 통해 주요 물성계수들이 압입시 하중-변위 곡선형상에 미치는 영향을 분석하였다. 또한 유한요소 압입해석을 통해 마찰계수의 영향으로 하중-변위 곡선, 시편하부의 단위부피당 변형에너지 및 변형률 주불변량이 바뀌지 않는 최적 압입깊이와 시편하부지점을 선정하였다. 이러한 관찰을 통해 하나의 요소에서 얻어지는 단위부피당 변형 에너지와 변형률 주불변량을 하중-변위 데이터와 모사 시킬 수 있는 무차원 함수를 얻을 수 있었으며, 이 과정에서 예측된 물성계수를 바탕으로 공칭응력-공칭변형률 곡선을 얻을 수 있었다.