• 대한기계학회논문집A
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• 제24권5호
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• pp.1203-1214
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• 2000

In this paper, a failure model for co-cured steel-composite tubular single lap joints has been proposed incorporating the nonlinear mechanical behavior of steel adherends and different failure mode s such as steel adherend failure and composite adherend failure. The characteristics of the co-cured steel-composite tubular single lap joint were investigated with respect to the test temperature, the stacking sequence of composite adherend, the thickness ratio of steel adherend to composite adherend, and the scarf ratio of steel adherend. Thus, the optimum design method for the co-cured steel-composite tubular single lap joint was suggested.

• 마이크로전자및패키징학회지
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• 제27권4호
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• pp.127-133
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• 2020

고분자 재료인 접착제와 금속 피착재 사이의 정량적인 접착강도 측정은 중요하다. 고분자 재료인 접착제와 금속 피착재 사이의 접착강도 측정 시, 피착재의 종류와 두께 변화가 접착강도에 미치는 영향에 대해 연구하였다. 금속 피착재의 종류로는 알루미늄과 스텐리스강 2종류가 선택되었으며, 접착강도의 측정에는 돌리테스트와 전단시험이 사용되었다. 인장응력 방식의 돌리테스트로 고분자 접착제와 금속 피착재 사이의 접착강도 측정 시, 금속 피착재의 두께 변화는 접착강도의 크기에 거의 영향을 미치지 않았으나, 피착재의 종류에 따라 접착강도는 다르게 나타났다. 반면, 전단시험으로 고분자 접착제와 금속 피착재 사이의 접착강도 측정 시, 금속 피착재의 상대적 두께 변화는 접착강도의 크기에 영향을 주었다. 이유는 전단시험 시 접착부의 모서리 부분에서 발생하는 피착재의 휘어짐 현상은 접착부에 추가적인 인장응력을 발생시켜 접착강도를 낮추는데 기여하기 때문이다. 이 연구의 결과, 돌리테스트는 피착재의 두께가 변해도 접착강도의 변화가 거의 없기 때문에 고분자 접착제와 금속 피착재의 정량적인 접착강도 측정 시 널리 사용될 것으로 예상된다.

• 대한기계학회논문집A
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• 제22권4호
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• pp.905-915
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• 1998

Static tensile tests using adhesive-bonded single-lap joints of aluminum alloy were conducted to investigate the effect of geometric factor, overlap length, adherend thickness, adhesive thickness and material composition of adherend/adhesive on the strength of adhesive joint. The average applied shear stress at joint fracture decreased with increasing lap length. However increasing the adherend thickness resulted in a higher joint strength. Higher yield strength of adherend and lower elastic modulus of adhesive is advantageous to the adhesive joint. Newly proposed modified joint factor could be well evaluated the influence of lap length, adherend thickness and adhesive thickness on the bond strength for adhesive joints.

• 한국자동차공학회논문집
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• 제6권4호
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• pp.56-65
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• 1998

The bonding strength evaluation of the light weight materials for an electrical vehicle has been performed through the T-peel joint test in which the design paramete- rs such as joint style, adherend type, adherend thickness, adhesive thickness, and adhesive type are considered. It is experimentally observed that the peel strength of joint increases with the increase of the adherend thickness. With the increase of the adhesive thickness, however, the peel strength of joint increases a little. Aluminum-FRP adherend combination shows such higher peel strength than that of Aluminum-Aluminum adherend combination. For the adhesive bonded joint, the results of FEM analysis agree with those of experiment. The adhesive bonded joint reinfored with a rivet gives higher peel strength than that of the joint without rivet.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.166-173
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• 1998

The evaluation of joint fatigue strength of light weight materials for an electrical vehicle body has been performed through T-peel joint tests with the design parameters such as joint style, adherend type, adherend thickness, adhesive thickness, and various adhesives. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the zero stress ratio. It was observed that the fatigue strength of the joint increases with the increase of the adherend thickness. With the increase of the adhesive thickness, however, the fatigue strength of the joint increases insignificantly. An aluminum-FRP adherend combination shows much higher fatigue strength than an aluminum-aluminum adherend combination. The results of fatigue tests were found to be consistent with those of static tests.

• 접착 및 계면
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• 제7권4호
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• pp.1-9
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• 2006

The single lap joint is the most studied joint in the literature in terms of both theory and practice. It is easy to manufacture and the lap shear strength is a useful value for strength assessment and quality control. Simple design rules exist such as the one present in standard ASTM 1002 or in a recent paper by Adams and Davies. The main factors that have an influence on the lap shear strength are the type of adhesive, i.e. ductile or brittle, the adherend yield strength and the overlap length. The overlap increases the shear strength almost linearly if the adhesive is sufficiently ductile and the adherend does not yield. For substrates that yield, a plateau is reached for a certain value of overlap corresponding to the yielding of the adherend. For intermediate or brittle adhesives, the analysis is more complex and needs further investigation. In order to quantify the influence of the adhesive, the adherend and the overlap on the lap shear strength, the experimental design technique of Taguchi was used. An experimental matrix of 27 tests was designed and each test was repeated three times. The influence of each variable could be assessed as well as the interactions between them using the statistical software Statview. The results show that the most important variable on the lap shear strength is the overlap length followed by the type of adherend.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.143-150
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• 1998

The evaluation of joint fatigue strength of light weight materials for electrical vehicle body has been performed through single lap joint tests with the design parameters such as joint style, adherend, bonding overlap length and bonding thickness. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the stress ratio zero value. It is experimentally observed that fatigue strength of joint increases for the increase of overlap length. The combinations of Al-Al and Al-FRP adherends show that fatigue strength of joint is hardly changed for the increase of bonding thickness, but FRP-FRP adherend specimen shows that fatigue strength of joint increases after decreases for the increase of bonding thickness. Al-Al adherend specimen has much higher fatigue length than Al-FRP and FRP-FRP adherend specimens. Riveting at adgesive bonded joint gives little effect on fatigue strength.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.87-93
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• 1997

The bonding strength evaluation of light weight materials for electrical vehicle applications has been performed through single lap joint tests in which the design parameters such as fillet, joint style, adherend, bonding overlap length,bonding thickness, and environmental condition(soaking time in $25^{\circ}C$ water) are considered. It is experimentally oberved that lap shear strength of joint increases for higher fillet height, longer overlap length, and thinner bonding layer thickness. Al-Al adherend combination shows much higher lap shear strength than AL-FRP and FRP-FRP adherend combinations. Riveting at adhesive bonded joint of AL-AL adherend combination makes lap shear strength decrease. Effect of soaking time on lap shear strength is negligible.

• 마이크로전자및패키징학회지
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• 제26권2호
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• pp.1-8
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• 2019

금속, 세라믹스, 플라스틱 등 고체의 표면에 적용되는 접착제와 페인트 도장막의 수요와 중요성은 점점 증가하고 있다. 본 연구에서는 금속 피착재에 고분자 재료인 접착제 혹은 페인트 도장막을 적용할 때, 이들 고분자 코팅층과 금속 피착재 사이의 접착강도 측정시 영향인자에 대한 연구를 돌리테스트로 수행하였다. 접착제로는 2액형 에폭시 접착제가 사용되었으며, 페인트로는 방청용 2액형 에폭시 페인트인 EH2350가 사용되었다. 특히, 영향인자로는 피착재의 종류(Al, Fe, STS, Cu, Zn), 표면거칠기 및 표면오염(수돗물, 소금물) 등을 선택해서 접착강도에 미치는 영향에 대해 연구하였다. 접착제와 피착재의 접착강도는 동일한 접착제를 사용해도 피착재의 종류가 달라지면 다르게 나타났으며, 수돗물 혹은 소금물로 산화 오염된 피착재의 표면은 페인트 도장공정 이전에 수돗물로 스프레이 세척이 필수적임을 알았다. 본 연구의 결과로 돌리테스트는 도장막과 피착재의 접착강도를 측정하는데 향후 널리 사용될 수 있음을 확인하였다.

• 대한기계학회논문집A
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• 제30권12호
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• pp.1543-1550
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• 2006

Since the performance of joints usually determines the structural efficiency of composite structures, an extensive knowledge of the behavior of adhesive joints and the related effect on joint strength is essential for design purposes. In this study, the torque capacity of adhesive joints was predicted using the combined thermal and mechanical analyses when the adherend was a composite tube. A finite element analysis was performed to evaluate residual thermal stresses developed in the joint, and mechanical s stresses in the adhesive were calculated including both the nonlinear adhesive behavior and the behavior of composite tubes. Three different joint failure modes were considered to predict joint failure: interfacial failure, adhesive bulk failure, and adherend failure. The influence of the composite adherend stacking angle on the residual thermal stresses was investigated, and how the residual thermal stresses affect the joint strength was also discussed. Finally, the predicted results were compared with experimental results available in literature.