• Title/Summary/Keyword: 접착구조물

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Adhesive Strength of dry Adhesive Structures Depending on the Thickness of Metal Coating (건식 접착 구조물의 금속 코팅 두께에 따른 접착강도 변화)

  • Kim, Gyu Hye;Kwon, Da Som;Kim, Mi Jung;Kim, Su Hee;Yoon, Ji Won;An, Tea Chang;Hwang, Hui Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.7
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    • pp.673-677
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    • 2016
  • Recently, engineering applications have started to adopt solutions inspired by nature. The peculiar adhesive properties of gecko skin are an example, as they allow the animal to move freely on vertical walls and even on ceilings. The high adhesive forces between gecko feet and walls are due to the hierarchical microscopical structure of the skin. In this study, the effect of metal coatings on the adhesive strength of synthetic, hierarchically structured, dry adhesives was investigated. Synthetic dry adhesives were fabricated using PDMS micro-molds prepared by photolithography. Metal coatings on synthetic dry adhesives were formed by plasma sputtering. Adhesive strength was measured by pure shear tests. The highest adhesion strengths were found with coatings composed of 4 nm thick layers of Indium, 8 nm thick layers of Zinc and 6 nm thick layers of Gold, respectively.

내열성 Modified PU접착제의 특성에 관한 연구

  • 강영구;김근유
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2003.10a
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    • pp.66-69
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    • 2003
  • 기능성 접착소재는 리벳이나 볼트를 이용한 기계적 접합에 비해 접합부의 하중 분산, 중량감소, 기밀 및 수밀 기능성 등의 장점이 있어 각종 구조물의 접착에 이용되고 있으나 Polymer를 주성분으로 하여 소재특성상 고온 노출 시 변형이나 접착 부위 파괴가 발생하는 등 단점을 가지고 있어, 구조물의 안전성 및 신뢰성 저하에 큰 영향을 미치는 요소이다.(중략)

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Effect of Surface Film on Void Behavior in Composite Integrated Structure (표면접착필름이 복합재 일체형 구조물에서의 기공 거동에 미치는 영향)

  • Park, Dong-Cheol;Kim, Yun-Hae
    • Composites Research
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    • v.33 no.3
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    • pp.147-152
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    • 2020
  • In this study, void behavior of composite laminate by local internal pressure gradient due to structural geometry and surface film application condition was experimentally evaluated through fabrication of spar/skin integrated structure specimens. Viscosity comparison and thermal analysis for both carbon fiber prepreg and surface film were conducted and cure characteristic and rate difference were analyzed. 2 types of spar/skin integrated structural specimens were prepared based on different application condition of surface film. Subsequently, those specimens were evaluated through visual surface inspection, non-destructive and destructive inspection. In a specimen #1 with full application of surface film, low pressurized area of composite laminate created by pressure gradient of structural geometry had voids. It exhibited that voids could not be evacuated and were locked in cured laminate by the influence of pre-cured surface film with relatively faster cure rate. In a specimen #2 without surface film, it revealed that all internal voids disappeared in the cured laminate. Therefore, it is verified that surface film acts as barrier film preventing void movement and evacuation during autoclave cure.

Evaluation Method of Bonded Strength in Adhesively Bonded Structures of the Aluminum Alloys (알루미늄 합금의 접착구조물에 대한 접착강도의 평가방법)

  • 정남용
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.1
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    • pp.35-44
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    • 1999
  • In a view point of earth environmental protection and social requirement, adhesively bonded structures of aluminum alloys have become to be employed for the purpose of decreasing fuel ratio by weight reduction and to improve performance in various engineering fields such as aircrafts, automobiles, rolling stocks and so on. In spite of such wide applications in adhesively bonded structures of aluminum alloys, the quantitative fracture criterion and evolution method of its bonded strength have not been established yet. The objective of this paper is to establish fracture criterion considering stress singularity at interface edges in adhesively bonded structures of aluminum alloys. Through the analyses of boundary element method and static fracture experiments with three different types of specimens in the adhesively bonded joints of aluminum alloys, its fracture criterion was proposed and discussed about strength evolution of adhesively bonded structures.

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Thickness Assessment of Adhesive Layer in Inhomogeneous Layer by Guided Wave (유도초음파에 의한 비균질 적층의 접합층두께 평가)

  • Cho, Youn-Ho;Ham, Hyo-Sik;Choi, Heung-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.21 no.4
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    • pp.391-397
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    • 2001
  • The guided wave propagation in inhomogeneous multi-layered structures is experimentally explored based on theoretical dispersion curves. It turns out that proper selection of incident angel and frequency is critical for guided wave generation in multi-layered structures. Theoretical dispersion curves greatly depend on adhesive zone thickness, layer thickness and material properties. It was possible to determine the adhesive zone thickness of an inhomogeneous multi-layered structure by monitoring experimentally the change of dispersion curves.

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Detection of Real Defects in Composite Structures by Laser Measuring System (레이저 계측시스템에 의한 복합재료 구조물의 실제결함 검출)

  • 정성균;김태형;김경석;강영준
    • Composites Research
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    • v.15 no.5
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    • pp.19-26
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    • 2002
  • Real defects in composite structures were detected by using laser measuring system. Four types of real defects, that is, impact-induced delamination in a composite laminate, debond in a honeycomb structure, free-edge delamination in a composite laminate and debond in an adhesive joint, were made by applying several types of loads to the specimens. Laser measuring system such as ESPI and shearography technique were used to detect those defects. Thermal loading method, which can easily induce the surface deformation of specimen, was used to detect the defects. Experimental results show that the defects in composite structures could be easily detected by ESPI and shearography technique. Moreover, it shows that ESPI and shearography technique could be usefully applied to the detection of defects in various kinds of composite structures.

Thickness Measurement of Adhesive Layer of Multilayer Using Power Cepstrum Technique (전력 켑스트럼 기법을 이용한 다층구조물 접착면의 두께측정)

  • Shin, Jin-Seob;Jun, Kye-Suk
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.2
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    • pp.26-30
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    • 1997
  • In this paper, the thickness measurement method of adhesive layers of multilayers using power cepstrum signal processing technique has been proposed. The peak values for reflected signal from each layer have been separated by power cepstrum technique. Therefore, thickness of adhesive layers have been measured by the intervals of peak signal. In the experiment, the adhesive layers of 0.5mm-0.75mm thickness using epoxy(2-Ton and Plastic Steel Putty(A)) between the aluminum and the brass were formed. The adhesive layer thickness which is calculated with data of reflected signal by ultrasonic pulse-echo method was within error 1.34% of the measured values.

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Detection of Defects in Composite Structures by using ESPI (ESPI를 이용한 복합재료 구조물의 결함 검출)

  • Kim, Kyung-Suk;Cheong, Seong-Kyun;Kang, Jin-Shik;Chang, Ho-Seob
    • Journal of the Korean Society for Nondestructive Testing
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    • v.21 no.3
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    • pp.299-306
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    • 2001
  • In this paper, artificial and real defects(delamination and debond) in composite structures were detected by using ESPI system. Three types of specimens, that is, composite laminates, honeycomb structures, and adhesive joints, were used to study the applicability of ESPI to composite structures. To detect defects in specimens, we selected thermal loading method that can easily induce the surface deformation of specimen. Experimental results show that defects in composite structures could be easily detected by ESPI. Moreover, it shows that ESPI could be usefully applied to the detection of defects in various composite structures.

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Epoxy계 및 Silicon계 접착제의 난연성 부여에 관한 연구

  • 강영구;김근유
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2003.05a
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    • pp.191-196
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    • 2003
  • 난연성 접착소재는 핵발전소, 선박, 철도차량, 항공기 등 고도의 화재 안전성 확보를 위한 구조재 및 내장재의 접착소재로서 테이프, 필름, 벌크 형태로 사용되고 있으며 건축분야에서도 구조물에 사용되는 접착 소재들의 난연화에 대한 중요성이 부각되어 그 에 따른 다양한 연구가 이루어지고 있다.(중략)

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Effects of Metal Coatings on Adhesive Characteristics of Gecko-like Micro Structures (도마뱀 인공섬모 구조물의 접착 특성에 금속코팅이 미치는 영향)

  • Kim, Gyu Hye;An, Tea Chang;Hwang, Hui Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.11
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    • pp.1099-1103
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    • 2015
  • Recently, there have been several studies on the inspiration and application of optimized natural structures. One study introduced a new adhesion method that was inspired by the feet of geckos because of their superior features such as high adhesion strength, ease-of-removal, and they are environmentally friendly. Various micro- or nano-structures were fabricated and tested for gecko-like dry adhesives, but gecko-like dry adhesives that were developed became easily worn from frequent use. In this study, we propose a metal-coating method to improve the durability of gecko-like dry adhesives. We evaluate the initial adhesion strength and durability by performing repeated adhesion tests on a glass plate. The initial adhesive strength of gold-coated micro-structures was 60% of that for non-coated ones. However, the adhesive strength of gold-coated micro-structures was kept as 58% of their initial adhesion strength, while that of non-coated ones was only 40%.