• 제목/요약/키워드: Mechanical property evaluation

검색결과 380건 처리시간 0.03초

박막의 기계적 물성을 위한 새로운 인장 시편 및 인장 시험기 (A Novel Tensile Specimen and Tensile Tester for Mechanical Properties of Thin Films)

  • 박준협;김윤재
    • 대한기계학회논문집A
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    • 제31권6호
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    • pp.644-650
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    • 2007
  • Mechanical property evaluation of micrometer-sized structures is necessary to help design reliable microelectromechanical systems(MEMS) devices. Most material properties are known to exhibit dependence on specimen size and such properties of microscale structures are not well characterized. This paper describes techniques developed for tensile testing of thin film used in MEMS. Epi-polycrystalline silicon is currently the most widely used material, and its tensile strength has been measured as 1.52GPa. We have developed a tensile testing machine for testing microscale specimen using electro-magnetic actuator. The field magnet and the moving coil taken from an audio-speaker were utilized as the components of the actuator. Structure of specimen was designed and manufactured for easy handling and alignment. In addition to the static tensile tests, it is described that new techniques and procedures can be adopted for high cycle fatigue test of a thin film.

고온 열화된 Inconel 600강의 미세조직 및 기계적 특성 평가 (Evaluation of Microstructure and Mechanical Property of Inconel 600 Degraded under High Temperature)

  • 정광후;김성종
    • 한국표면공학회지
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    • 제50권6호
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    • pp.492-497
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    • 2017
  • In this study, we investigated the effect of thermal aging on mechanical characteristics of Inconel 600 nickel-based alloy. The thermal aging was conducted up to 1000 hours at an atmosphere of $650^{\circ}C$. The microstructure of thermally aged specimens was investigated by an optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). In addition, tensile test (strain rate: 2 mm/min) and micro Vickers hardness test were conducted to evaluate mechanical properties with time. As a result of the experiment, Cr-rich carbide continuously precipitated during thermal aging, leading to the change of the mechanical characteristics and fracture mode. With the increase of aging time, tensile strength, yield strength, and hardness gradually decreased. The fracture mode changed from ductile to brittle with the increase of grain boundary carbide.

향상된 구형압입 고무 물성평가법 (Enhanced Spherical Indentation Techniques for Rubber Property Evaluation)

  • 황규민;오중수;이형일
    • 대한기계학회논문집A
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    • 제33권12호
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    • pp.1357-1365
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    • 2009
  • In this study, we enhance the numerical approach of Lee et al.$^{(1)}$ to spherical indentation technique for property evaluation of hyper-elastic rubber. We first determine the friction coefficient between rubber and indenter in a practical viewpoint. We perform finite element numerical simulations for deeper indentation depth. An optimal data acquisition spot is selected, which features sufficiently large strain energy density and negligible frictional effect. We then improve two normalized functions mapping an indentation load vs. deflection curve into a strain energy density vs. first invariant curve, the latter of which in turn gives the Yeoh-model constants. The enhanced spherical indentation approach produces the rubber material properties with an average error of less than 3%.

박막 물성평가 압입시험의 수치접근법 (A Numerical Approach to Indentation Techniques for Thin-film Property Evaluation)

  • 이진행;유한석;이형일
    • 대한기계학회논문집A
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    • 제31권3호
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    • pp.313-321
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    • 2007
  • In this work, the prior indentation theory for a bulk material is extended to an indentation theory for evaluation of thin-film material properties. We first select the optimal data acquisition location, where the strain gradient is the least and the effect of friction is negligible. A new numerical approach to the thin-film indentation technique is then proposed by examining the finite element solutions at the optimal point. With this new approach, from the load-depth curve, we obtain the values of Young's modulus, yield strength, strain-hardening exponent. The average errors of those values are less than 3, 5, 8% respectively.

경량기포 모르타르를 이용한 NATM Composite 라이닝 터널 뒤채움재의 역학적 특성 평가 (An Evaluation of the Mechanical Property for the Backfilling Material of the NATM Composite Lining Tunnel using the Lightweight Foamed Mortar)

  • 마상준;최희섭;김동민;이흥수;김경덕
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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    • pp.717-720
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    • 2008
  • This paper, an evaluation of the mechanical property for the backfilling materials of the NATM Composite lining tunnel using the lightweight foamed mortar, relates to the performance of permeability, compressive strength and unit volume weight. Therefore, this study is aimed to prove the three main factor that refered to the above line for development of new tunnel method. As the result of this study, it would be confirmed that the D mix is better than other mixs a side of all tests and its relation that is for the tunnel backfilling materials.

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소형펀치 시험법에 의한 초전도 마그넷 구조용강 TIG 용접부의 극저온 파괴특성 평가 (Evaluation of Cryogenic Fracture Characteristics on TIG Weldments of Superconducting Magnets Structural Steel by Small Punch Testing Method)

  • 권일현;;정세희
    • Journal of Welding and Joining
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    • 제14권5호
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    • pp.122-133
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    • 1996
  • In order to evaluate the cryogenic fracture characteristics of structural steels for superconducting magnets of fusion reactor, small punch (SP) testing was performed on austenitic stainless steel (JN1 base metal) and its TIG weldments at 293K, 77K and 4K. The mechanical properties with respect to the extracted location of the weld metal, on the effects of welding heat cycle about base metal near fusion line in TIG weldments were investigated. The mechanical property of the weld metal in TIG weldments depends on distance from welding root, root region of weldments having the lowest mechanical property. The base metal near fusion line showed degradation of mechanical property caused by cyclic heating during the TIG welding. Based on the test results, HAZ was found to be up to 5mm from the fusion line. It is shown that SP testing is a useful tool to evaluate the mechanical properties with respect to the microstructures changes such as HAZ as well as weld metal in TIG weldments at cryogenic temperature.

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MEMS 소재의 기계적 특성 평가를 위한 인장형 시편 및 시험기 제작 (A Novel Tensile Specimen and Test Machine for Mechanical Properties of MEMS Materials)

  • 박준협;김정엽;이창승;좌성훈;송지호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.258-263
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    • 2004
  • Mechanical property evaluation of micrometer-sized structures is necessary to help design reliable microelectromechanical systems(MEMS) devices. Most material properties are known to exhibit dependence on specimen size and such properties of microscale structures are not well characterized. This paper describes techniques developed for tensile testing of materials used in MEMS. Epi-polycrystalline silicon is currently the most widely used material, and its tensile strength has been measured as 1.52GPa. We have developed an uniaxial testing machine for testing microscale specimen using electro-magnetic actuator. The field magnet and the moving coil taken from an audio-speaker were utilized as the components of the actuator. Structure of specimen was designed and manufactured for easy handling and alignment. In addition to the static tensile tests, new techniques and procedures for measuring strength are described.

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타월용 시판소재의 촉감과 역학적 특성 (Tactility and Mechanical Properties of Marketing Towel)

  • 정하경;김선경;조효숙;김주용
    • 대한가정학회지
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    • 제44권10호
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    • pp.57-66
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    • 2006
  • The purpose of this study was to evaluate the relationship between the tactile sensation and mechanical properties of towel. Six kinds of towels with different surface structure and fiber composition were used for this study. To evaluate the tactility of towel, 36 adjectives were collected and then 11 adjectives were selected. The subjective evaluation was examined by one to one comparative method and by blind test for estimating the only the sense of touch of the towels. Kawabata's Evaluation system for fabrics was used to measure the mechanical properties which are tensile, bending, shear, compression, surface, weight, and thickness of six towels. The results are as follows; First, surface structure of the towels had an effect on estimation the sense of touch. Pile surface was evaluated thicker, compacter, more cushiony, and more elastic. Waffle surface was evaluated knottier and rougher, and microfiber suede surface was evaluated softer and denser. Second, the highest value of the mechanical properties measured were G, 2HG, B, and SMD of 100% cotton 100% pile, WC, T, and W of elban loop pile, WT, 2HB, and LC of 100% cotton cut pile, RT and MIU of microfiber suede, and RC of microfiber waffle. Third, the 11 adjectives were correlated with more than one mechanical property. 'Knotty' and 'rough' were correlated with MMD and SMD, 'soft' were correlated with B, 2HB, MMD, and SMD. 'Thick', 'heavy', 'compact', and 'elastic' were correlated with WC, T, and W, 'cushiony' was correlated with WC. 'Stiff' was correlated with B and 2HB, 'dry out' was correlated with RT, WC, MIU, and T. 'Dense' was correlated with RT and SMD.

치과용 시술기구(Micro Handpiece)재료의 특성평가 및 표면품질에 대한 연구 (Study on Evaluation of Material Property of Micro Handpiece for dentistry and Surface Quality)

  • 손재환;한창우;최상일;김용중;최창진
    • 한국산업융합학회 논문집
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    • 제9권3호
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    • pp.221-228
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    • 2006
  • As Industrialization gets more and more advanced, human technological medical apparatus for dentistry has been developed. Such a medical apparatus have to let precision revolution and torque control facilitate. Consequently, Development of Micro hand-piece with strong durability should be required. Moreover, It's also very important to evaluate performance of such a Micro hand-piece, Evaluation of Mechanical property of Material and ANOVA have been known as useful methods in the field of Quality Evaluation. For Verification of Quality Evaluation, It has been evaluated by One-way layout ANOVA based on the data of Surface Roughness Test. Anyhow, This test has been respectively carried out by 3 kinds of Test and Superior performance has appeared in the Test result.

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