• 제목/요약/키워드: tensile tester

검색결과 168건 처리시간 0.025초

자유지지 박막의 기계적 물성 측정을 위한 띠굽힘시험기의 개발 및 검증 (Development and validation of strip bending tester for measuring mechanical properties of freestanding thin films)

  • 박정민;김재현;이학주
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.49-55
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    • 2008
  • Strip bending test has been frequently utilized to measure the mechanical properties of freestanding thin films in substitute for the micro-tensile test. However, in spite of its simplicity and reliability, strip bending test has a few problems, for example, the measurement of strain and the calculation of stress at zero strain. In this study, these problems are precisely reviewed and proved. Upon this review, strip bending tester has been developed, which uses the confocal laser displacement meter to measure the deformed configuration of the specimen and the possibility and limitation of this testing system is carefully investigated including the estimation of uncertainty of the measurement of strain. Finally, to prevent errors and to improve the accuracy of this testing system, the shape of the specimen has been carefully studied and is proposed.

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치과용 Co-Cr 합금의 제성질에 미치는 Boron과 Silicon의 영향 (Effect Boron and Silicon on Various Properties of Dental Cobalt-Chromium Alloys)

  • 정종현
    • 대한치과기공학회지
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    • 제14권1호
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    • pp.119-132
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    • 1992
  • This paper aims to investigate the effect of B and Si upon the mechanical properties, microstructure and corrosion resistance of Co-Cr base alloy. Ten groups of alloy ingot ingot with various contents of B and Si were remelted by high frequency electrical induction furnace and cast into tensile specimen of ADA Specification No. 14 Tensile and hardness test were carried out by Amsler and Rockwell hardness tester(R-30N), respectively. The microstructures of specimen were observed by SEM. The results obtained are summarized as follows : 1. As B content is increased, tensile strength, yield strength and Rockwell hardness number(R-30N) are also increased significantly, while the elongation is decreased significantly. 2. As Si contect os increased, no significant chang in tensile strength is noticed, yield strength is slightly decreased, but Rockwell hardness number(R-30N) is moderately in creased, Elongation marks maxium value with 1% Si content while with more than 1% Si it is decreased. 3. As B content is increased corrosion resistance is decreased and is at best with 1.5% B content. Corrosion resistance is increased with the increase of Si content and the alloys with Si over 3.0% showed corrosion resistance. 4. As B content increased, precipitates are increased in number at grain boundaries. The grain size tends to become coarse with the increase of Si content. 5. Co rich-Cr alloy is present through matrix whereas at the grain boundaries Cr base precipitates are primarily formed.

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윤하중 시험과 유한요소해석을 통한 강상판 교면포장의 거동분석 연구 (An Evaluation of Orthotropic Steel Bridge Deck Pavement Behavior Using Wheel Load Testing and 3D Finite Element Analysis)

  • 김태우;최지영;이현종;백종은;엄병식
    • 한국도로학회논문집
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    • 제15권1호
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    • pp.103-110
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    • 2013
  • PURPOSES: The objective of this study is to analyze and evaluate the behavior of orthotropic steel bridge deck pavement using three-dimensional finite element analysis and full-scale wheel load testing. METHODS: Since the layer thickness and material properties used in the bridge deck pavement are different from its condition, it is very difficult to measure and access the behavior of bridge deck pavement in the field. To solve this problem, the full-scale wheel load testing was conducted on the PSMA/Mastic bridge deck pavement and the deflection of bridge deck and horizontal tensile strain on top of pavement were measured under the loading condition. Three-dimensional finite element analysis was conducted to predict the behavior of bridge deck pavement and the predicted deflection and tensile strain values are compared with measured values from the wheel loading testing. RESULTS: Test results showed that the predicted deflections are 10% lower than measured ones and the error between predicted and measured horizontal tensile strain values is less than 2% in the critical location. CONCLUSIONS: The fact indicates that the proposed the analysis is found to be accurate for estimating the behavior of bridge deck pavements.

자외선 보호성분이 포함된 헤어오일의 자외선에 대한 모발 보호성능 연구 (UV Protection Effect of Hair Treated with Hair Oils Containing UV Protective Substances)

  • 김수환;박선화;안춘순
    • 한국의류학회지
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    • 제44권6호
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    • pp.1205-1223
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    • 2020
  • This research investigated the protective effect on hair for 3 commercial hair oil products containing UV filters upon UVA and UVB irradiation. Hair tresses each weighing 2 g were prepared from black virgin hair. Hair tresses treated with 0.5 g of hair oil were irradiated by UVA (365 nm) and UVB (302 nm) lamp for up to 600 hours. Color of hair was measured using a spectrocolorimeter, tensile strength and elongation of hair were measured using a biological tensile tester, surface morphology was examined using a scanning electron microscope. Experimental results were analyzed using SPSS statistical software. Hair color and tensile strength were both affected by UVA and UVB irradiation. Significant differences in the color and tensile strength were observed between untreated hair and hair treated with hair oils. Good UV protective effect observed in Oil 2 and Oil 3 was attributable to the type and the combination of UV filters contained in the products.

토글식 사출성형기의 타이바 연신율 평가 (Tie-bar Elongation Evaluation of Toggle Type Injection Molding Machine)

  • 정현석;유중학
    • 한국생산제조학회지
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    • 제21권4호
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    • pp.672-676
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    • 2012
  • This paper studies the relation between the deformation of platen caused by clamping force, the bending stress and elongation at the tie-bar in injection molding machine of toggle type. These data are analyzed through analytical molding and numerical approach by tensile tester. The effect of bending stress on the stress concentration of teeth and nut system is also analyzed by 2 dimensional numerical approach. The bending stress of tie-bar caused by platen deformation becomes less than 20% of average tensile stress. And the effect of bending stress on stress concentration at teeth and nut system of tie-bar is found to be small.

철도차량용 유리섬유직물/페놀릭 복합재의 가속노화 특성 (Aging Characteristics of Glass Fabric/Phenolic Composites in Train Carbody)

  • 윤성호;남정표;황영은;신광복
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.352-357
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    • 2004
  • In this study. the effects of combined environmental factors on mechanical and thermal analysis properties of graphite/epoxy composites were evaluated through a 2.5KW accelerated environmental aging tester. Environmental factors such as temperature. moisture, and ultraviolet were considered. A xenon-arc lamp was utilized for ultraviolet light. and exposure times of up to 3000 hours were applied. Several types of specimens - tensile, bending, and shear specimens those are warp direction and fill direction were used to investigate the effects of environmental factors on mechanical properties of the composites. The glass fabric $\sharp$650/AP300 was used for the fabrication of specimens. Mechanical degradations for tensile, bending and shear properties were evaluated through a UTM. Also. storage shear modulus. loss shear modulus, and tan $\delta$ were measured as a function of exposure times through a dynamic mechanical analyzer. Finally exposed surfaces of the composites were examined using II scanning electron microscope.

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치과주조용 금-은-팔라듐합금의 물리적 특성에 관한 연구

  • 김철위
    • 대한치과의사협회지
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    • 제20권12호통권163호
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    • pp.1073-1081
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    • 1982
  • The purpose of this study was to measure and compare the tensile strengths, elongation and Vicker's hardness values by heat treatments of three·commercial dental casting gold-silver-palladium alloys(Type A,B and G-50 alloys) used in Korea. Instron universal testing instrument and Vicker's hardness tester were used to determine their physical properties. The following results were obtained with the alloys tested. 1. It was determined that the tensile strengths generally tended to increase as the hardened condition (55.50 - 72.98 Kg/mm₂)than in softened condition (28.75 - 41.16 Kg/mm₂). 2. The results indicated that the elongation was the highest in the softened condition(12.30 - 27.0 %), and was the smallest in the hardened condition (3.6 - 5.8 %). 3. It was found that the Vicker's hardness number was the greatest in type G-50 hardened alloys (304.0), and the smallest in the type A softened alloys (130.0).

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Thermal Assisted UV-Ozone Treatment to Improve Reliability of Ag Nanoparticle Thin Films

  • Lee, Inhwa;Kim, Taek-Soo
    • 마이크로전자및패키징학회지
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    • 제21권1호
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    • pp.41-44
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    • 2014
  • We employed UV-Ozone treatment method for the fabrication of dense and highly conductive nanoparticle thin films. We demonstrated the UV-Ozone treatment effect on the silver nanoparticle thin films as a function of time and temperature. The capping layers of nanoparticles were decomposed after UV-Ozone treatment and dense nanoparticle thin films were obtained. Moreover, electrical and mechanical properties of the thin films after UV-Ozone treatment were measured by using resistance measurements under tension in an in-situ tensile tester. The initial resistance of nanoparticle thin films was decreased by 82.6% with optimized UV-Ozone treatment condition of $150^{\circ}C$ for 20 minutes.

Synthesis of Biomass-derived Polyurethane by Chain Extender Type

  • Sohn, Mi Hyun;Li, Xiang Xu;Cho, Ur Ryong
    • Elastomers and Composites
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    • 제54권4호
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    • pp.279-285
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    • 2019
  • Bio-based polyester polyols were synthesized using esterification with azelaic acid, sebacic acid, and 1,3-propanediol. Polyurethanes were prepared using chain extenders (1,4-Butanediol, 1,3-Propanediol, and isosorbide) and 4,4'-diphenylmethane diisocyanate with a mixing ratio of 1:1:1.1. Subsequently, the properties of the polymers prepared using the different chain extenders were compared. The synthesis of polyurethane was confirmed by FT-IR, TGA, and GPC. The mechanical properties (hardness, ball rebound, and tensile strength) of the materials were analyzed using shore A tester, taber abrasion, and UTM. heat, chemical, and water resistances of the prepared materials were measured by comparing the tensile strengths according to external changes.

실내 시험기에 의한 지오그리드의 시공 시 손상 평가 (Installation Damage Assessment of Geogrids by Laboratory Tester)

  • 진용범;변성원;전한용
    • 한국지반신소재학회논문집
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    • 제5권4호
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    • pp.43-47
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    • 2006
  • 다짐조건을 달리하여 3가지 종류 지오그리드의 내시공성을 측정하였다. 이 실험은 ENV ISO 10722-1에 근거하여 실행되었다. 채움재와 관계없이 다짐횟수가 증가할수록 지오그리드의 인장강도는 감소하였으며, 지오그리드 종류에 따라 감소되는 경향이 다르게 나타남을 알 수 있었다. Woven 및 warp-knitted type 지오그리드의 경우 접합형 지오그리드에 비해 더 큰 감소경향을 나타내었다.

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