• 한국항공우주학회지
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• 제35권3호
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• pp.204-211
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• 2007

연구에서는 5가지의 접착길이를 갖는 탄소 복합재-알루미늄 단일겹침 체결부에 대한 실험을 통해 단일겹침 접착 체결부의 파손양상 및 강도를 연구하였다. 시편은 필름 형태의 접착제인 FM73m을 사용하여 이차접착으로 제작하였다. 실험 결과, 이종재료 접착 체결부의 강도는 금속-금속 체결부의 강도보다는 낮고, 복합재-복합재 체결부의 강도보다는 높게 나타났다. 접착길이 대 폭의 비가 1보다 작은 경우, 접착길이의 증가가 강도 저하에 미치는 영향이 컸지만, 접착길이 대 폭의 비가 커질수록 접착길이의 효과는 줄어드는 것으로 나타났다. 모든 시편은 최종적으로 층간분리의 형태로 파손되었다. 따라서 고강도 접착제를 사용한 체결부의 강도향상을 위해서는 적층판의 층간분리 파손을 지연시킬 수 있는 설계가 중요할 것으로 판단된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1347-1348
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• 2013

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.796-801
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• 2007

The optical performance of the mirror for satellite camera is highly dependent on the adhesive properties between the mirror and its support. In order to design a mirror with high optical performance, the mechanical properties of adhesives should be well defined. In this research, the mechanical properties of three kinds of space adhesives are studied. In case of the materials which show nearly incompressible behavior such as space adhesives, it is important to measure shear modulus which governs deviatoric stress components. Shear moduli of the adhesives are determined by using single lap adhesively bonded joint. For the shear tests, several points have been selected from $-20^{\circ}C$ to $50^{\circ}C$ which is operating temperature range of the adhesive. The shear modulus of each adhesive is expressed as a function of temperature. Characteristics of the adhesives are discussed regarding their temperature sensitivity. The analysis results of RMS wavefront error w.r.t shear modulus are presented.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.139-140
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• 2017

This technology employs a method of forming a single-ply PLUS waterproofing sheet layer comprised of applying a single-ply synthetic polymer layer on a vibrating structure (steel frame, RC) or an inclined surface by using a T joint lap-filling coil and an embedded metal coated sheet. The T - joint reinforcing lap-filling coil was used to block the ingress channel of the rainwater by applying the material in the vulnerable area where the three sides of the waterproof sheet overlapped. Conventional waterproofing techniques have a problem in that the waterproof sheet is pierced because the end portion of the waterproof sheet applied to the vertical portion is fixed by a nail, and the sealant applied to the end portion of the sheet cannot easily secure long-term waterproof durability due to the influence of the external environment. Therefore, the developed technology secured the waterproof durability against the vertical part by using the embedded metal sheet. In addition, automatic hot-air fusing is used to improve the quality of waterproof construction and point fixation method using fixed hardware. This is a technology that is not significantly restricted in the high degradation level regions of domestic waterproof construction environments in Korea such as low-temperature environment, wet floor.

• Journal of Welding and Joining
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• 제33권4호
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• pp.44-49
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• 2015

The structural epoxy adhesive used in car body assembly needs the highest level of joint mechanical strength under lap shear, T-peel and impact peel conditions. In this study, the effect of nano functionalized block copolymer addition on the impact peel strength of epoxy adhesive was investigated. DSC analysis showed that the addition of nano functionalized block copolymer did not affect the curing reaction of epoxy adhesive. From single lap shear test, it was found out that the addition of nano functionalized block copolymer slightly decreased the cohesive strength of cured adhesive layer. The addition of nano functionalized block copolymer showed beneficial effect on T-peel strength by changing the adhesive failure mode to the mixed mode. However, the addition of nano functionalized block copolymer just decreased the room temperature impact peel strength. It was considered that the addition of nano functionalized block copolymer could have effect on disturbing the crack propagation only for the case of slow strain rate.

• 한국철도학회논문집
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• 제13권6호
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• pp.546-551
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• 2010

본 연구에서는 단일겹치기 접착 체결부에 대한 유한요소해석을 통해 요소의 조밀도 및 유한요소의 종류에 따른 접착 층의 변형률 분포를 Tsai의 시험치 와 비교하여 분석하였다. 이를 위해 접합부재의 길이방향, 접착체결부의 길이방향, 접합부재의 두께방향, 접착 층의 두께방향 및 조인트의 폭방향의 요소 조밀 도를 변화시켰다. 또한, 솔리드, 쉘 및 평면 변형률 요소에 따른 효과도 분석하였다. 해석은 단일 겹치기 접착 체결부의 대변형을 고려하기 위한 기하학적 비선형 해석을 수행하였다. 이를 통해 솔리드 요소를 적용할 경우 접착부재의 길이방향으로의 요소 수는 최소 2개 이상이면 해석의 신뢰도를 확보할 수 있음을 확인할 수 있었다. 쉘 요소의 겨우 x/c=1에서 수직 변형률의 시험결과와 22.8%의 오차를 보였으나, 전단응력의 경우에는 1.67%로 시험치와 거의 일치하였다.

• Composites Research
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• 제20권5호
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• pp.34-42
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• 2007

본 논문에서는 탄소 복합재와 알루미늄으로 구성된 이종재료 단일겹침 접착 체결부에서, 파손하중에 영향을 미치는 주요인자들의 효과를 실험적으로 연구하였다. 실험을 위해 접착압력 4가지(2, 3, 4, 6기압), 겹침길이 6가지(15, 20, 25, 30, 35, 40 mm), 모재 두께 2가지(1.58, 3.01 mm)에 대한 시편 총 66개를 제작하였다. 실험 결과 접착제 FM73에 대해 제작사에서 제시한 접착압력은 약 3기압이었지만 본 연구에서 사용한 이종재료 접착의 경우, 최소 4기압 이상의 접착압력이 필요함을 확인하였다. 겹침길이를 증가시킬 경우 파손하중이 증가하지만 접착부의 폭과 길이의 비가 1을 넘어갈 경우 접착강도 즉 단위 접착면적당의 파손하중의 증가는 크지 않았다. 모재의 두께도 접착부 파손하중 및 강도에 큰 영향을 미쳤으며 모재의 두께가 약 2배로 증가할 때 접착강도는 $12{\sim}32%$까지 증가하였다. 접착부의 파손은 대부분 복합재 모재의 층간분리 형태로 발생하였으며, 접착압력이 높아질수록, 접착길이가 길어질수록 층간분리가 발생하는 위치가 적층판 내부로 깊게 확대되는 경향이 있다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 1999년도 춘계학술발표대회 논문집
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• pp.57.1-60
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• 1999

This paper presents the effects of partial dampers on the lateral vibration of beams. Both shear and normal stresses in the viscoelastic layer were studied. Analytical results were compared with those obtained by a finite element method. Effects of the size of partial dampers on the system loss factors and resonant frequencies were discussed.

• 연구논문집
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• 통권27호
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• pp.175-181
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• 1997

Superconducting joints between Bi-2223/Ag tapes are fabricated by a press & reaction anneal and a multiple press & anneal. The silver sheath was mechanically or chemically removed from one side of each tape without altering the superconducting core. The exposed superconducting core of the two tapes were brought into contact and pressed so as to form a lap joint. The joined tapes were then subjected to a series of different thermomechanical treatments to achieve optimum heat treatment condition. The result from transport measurements shows that critical current ($I_c$) transmitting through joined area reaches 9A, approximately 60% of the current capacity of the tapes themselves. The critical current through joined area was improved by repeated press and reaction annealing. Measurements of the current-voltage relationship were made with several configuration of the voltage probes to characterize the critical current variation and I-V curve along the joint. Also discussed are microstructural aspects of the superconducting joint.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.234-238
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• 2005

One approach to testing the suitability of a adhesive joint for a particular application is to build and test to destruction of a representative sample of the joint. The nondestructive test will not measure strength directly but will measure a parameter which can be correlated to the strength. It is therefore, essential that a suitable nondestructive test is chosen and its results are correctly interpreted. In this paper, typical ultrasonic signal analysis in adhesive joints are evaluated together with interface stress from the result of finite element analysis.