• 대한치과교정학회지
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• 제33권5호
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• pp.359-370
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• 2003

본 연구는 교정용 금속 브라켓에 다양한 방향에서의 복합적인 응력을 가하여 힘의 방향과 적용점에 따른 교정용 브라켓의 결합강도를 비교하고, 브라켓의 유지력을 평가하는데 기준이 되는 최소결합강도의 특성에 대해 알아보고자 시행되었다. 일정 한 표면특성을 갖는 금속봉에 Micro-Loc base, Chessboard base, Non-etched Foil-Mesh base 등 서로 다른 기저 면 형태를 가지는 3가지 종류의 금속 브라켓을 부착시키고, $0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;60^{\circ},\;75^{\circ},\;90^{\circ}$의 Peel 결합강도$(_0PBS, \;_{15}PBS,\;_{30}PBS,\;_{45}PBS,\;_{60}PBS,\;_{75}PBS,\;_{90}PBS)$ 및 전단결합강도(SBS)와 인장결합강도(TBS)에 대한 브라켓의 결합강도를 측정하고, 각 브라켓의 기저면 면적을 고려하여 단위면적당 결합강도를 산출하여 비교한 결과 다음과 같은 결론을 얻었다. 1. Micro-Loc base와 Chessboard base 및 Non-etched Foil-Mesh base 브라켓 모두에서 전단결합강도(SBS)가 가장 컸다(P<0.01). 2. Peel 응력의 방향 변화에 따른 peel 결합강도(PBS)의 변화양상은 Micro-Loc base와 Chessboard base, Non-etched Foil-Mesh base 브라켓 모두에서 유사하였으며 (p>0.05), peel 응력의 적용 각이 증가할수록 peel 결합강도(PBS)는 감소하였고 $60^{\circ}$에서 최저값을 보였다(p<0.05). 3. Micro-Loc base에서 최저 peel 결합강도$(_{60}PBS)$는 전단결합강도(SBS)의 $29\%$ 수준이었으며, 인장결합강토(TBS)에 대해서는 $52\%$ 수준이었고, Chessboard base에서 최저 Peel bond strength$(_{60}PBS)$는 전단결합강도(SBS)의 $34\%$ 수준이었으며, 인장결합강도(TBS)에 대해서는 $61\%$ 수준이었으며, Non-etched Foil-Mesh base에서 최저 Peel 결합 강도$(_{60}PBS)$는 전단결합강도(SBS)의 $34\%$ 수준이었으며, 인장결합강도(TBS)에 대해서는 $55\%$ 수준이었다. 4. 단위 면적 당 결합강도에 있어서 전단결합강도(SBS)와 인장결합강도(TBS) 및 $75^{\circ}\;와\;90^{\circ}$ peel 결합강도는 Micro-Loc base와 Chessboard base에서 차이 가 없었으며 Non-etched Foil-Mesh base에서 가장 작았고(p<0.05), $0^{\circ},\;15^{\circ},\;30^{\circ},\;60^{\circ}$ peel응력을 적용한 결과 Chessboard base에서 가장 큰 Peel결합강도를, Non-etched Foil-Mesh base에서 가장 작은 결합강도를 보였다(p<0.05).

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.98-107
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• 2004

The objectives of this research are to establish the criteria of peel occurrence considering the shape of bond terminus and to compare the strength properties of some adhesive joints. The criteria of feel occurrence at the bond terminus was suggested. Peel loads of some adhesive joint(butt joint, T -shape specimen, single lap joint) were determined from tensile tests. Principal stress distributions of these joints were determined from finite element method analysis. Then, peel occurrence was estimated with intensity of stress singularity ' $K_{prin.}$' when the terminus shape was square, with average principal stress when the terminus shape was rounded. The conclusions are summarized as follows; (1) In the non-filleted model(e.g., butt joint, T-shape specimen), principal stress shows singularity at the bond terminus, intensity of stress(principal stress) singularity ' $K_{prin.}$&apso; can use as the criteria of peel occurrence at the bond terminus. (2) In the filleted model(e.g., single lap joint), principal stress doesn't show singularity at the bond terminus. Average principal stress can use as the criteria of peel occurrence at the bond terminus.'t show singularity at the bond terminus. Average principal stress can use as the criteria of peel occurrence at the bond terminus.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.38-43
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• 2001

The interfacial adhesive joining characteristics of the foams are very important for the structural integrity of sandwich structures. Peel strength is one of the best criteria for the interfacial characteristics of the sandwich structures and peel energy is most commonly used for the interfacial characteristics. The peel strength is the first peak force per unit width of bond line required to produce progressive separation by the wedge or other crack opening type action of two adherends where one or both undergo significant bending and the peel energy is the surface active energy per unit width of bond line. In this work, to investigate the strengthening effect of resin treatment on the interfacial surface of foam material, peel strength and peel energy of epoxy resin treated polyurethane foam core sandwich structures were obtained by the cleavage peel tests and compared with those of non surface treated polyurethane foam core sandwich structures.

• 한국공작기계학회논문집
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• 제14권5호
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• pp.62-73
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• 2005

The objects of this research are to establish the criteria of peel occurrence considering the shape of bond terminus and to compare the strength properties of adhesive joint of different three type such as butt joint, T-shape, and single lap Joints. The criteria of peel occurrence at the bond terminus was suggested. Peel loads of three type adhesive joint (butt Joint, T-shape specimen, single lap joint) were determined from tensile tests. Principal stress distributions of these joints were determined from finite element method analysis. Then, peel occurrence was estimated with stress singularity factor$(K_{prin})$ when the terminus shape was square, with average principal stress when the terminus shape was rounded. The conclusions are summarized as follows; (1) In the non-filleted model(e.g., butt joint, T-shape specimen), principal stress shows singularity at the bond terminus, intensity of stress(principal stress) singularity $(K_{prin})$ can use as the criteria of peel occurrence at the bond terminus. (2) In the filleted model(e.g., single lap joint), principal stress has not affected singularity at the bond terminus. Average principal stress$(K_{av})$ can use as the criteria of peel occurrence at the bond terminus.

• 한국표면공학회지
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• 제28권4호
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• pp.219-224
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• 1995

The peel adhesion and plastic deformation in Cu-Cr alloy films, sputter-deposited onto polyimide films, have been studied as a function of Cr content in the film. The adhesion strength has been measured by T-peel test and the amount of plastic deformation in the peeled metal strip was determined qualitatively by XRD technique. Peel adhesion strength has a maximum in the film containing 22-33wt.% Cr and the peel strength of pure Cr film is lower than the maximum. The film having the highest peel strength is deformed most heavily. The effect of Cr content on the peel strength is discussed in terms of the interfacial bond strength and mechanical properties of Cu-Cr alloy film.

• 구강회복응용과학지
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• 제16권2호
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• pp.123-132
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• 2000

The field of maxillofacial prosthetics is concerned with the prosthetic reconstruction of missing head and neck tissue. Currently, facial prostheses are usually applied in cases of defects caused by the surgical removal of tumors or congenital defects. While silicone has been most widely used for the reconstruction of missing maxillofacial defects, it does not have ideal physical properties. Therefore, bonding a thin polyurethane sheet to silicone prostheses was recommended. In this case skin adhesives were used for the retention of maxillofacial prostheses. But retention of devices has always been problematic. The contributions of implants can be made to solve these problems. Implants have reduced the need for adhesive use, simplifying cleaning procedures and thus extending the life of the prostheses. For implant-retained prostheses, retentive matrix is necessary to hold attachments and/or magnets. The retentive matrix is usually fabricated with autopolymerizing acrylic resin or visible light- polymerized resin. The purpose of this study was to compare the adhesion-in-peel force of silicone adhesive to autopolymerizing acrylic resin and polyurethane sheet with two different surface textures : pumice polish only or retention groove, and three surface primers : Dow corning 1205 primer or Dow corning S-2260 primer or FactorII A-304 primer, and two polymerization methods : room temperature or dry heat oven. The t-peel bond strength of specimens was determined as described in ASTM Standard D1876-72. The results were statistically analyzed using the ANOVA test, multiple range test and t-test The results were as follows. 1. The t-peel bond strength of A-304 primer was the highest and statistically higher than that of S-2260(p<0.05). 2. The t-peel bond strength of specimens with retention groove was statistically higher than that of specimens polished with pumice(p<0.05). 3. The t-peel bond strength of specimens polymerized in dry heat oven was statistically higher than that of specimens in room temperature(p<0.01).

• 대한기계학회논문집A
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• 제26권3호
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• pp.570-575
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• 2002

It is well-known that the bond strength between CFRP(Carbon Fiber Reinforced Plastic) and aluminum is significantly affected by the surface treatment of the CFRP and the aluminum. This study investigates the surface treatment of CFRP to improve the T-peel strength of CFRP/aluminum composites. The surface of %CFRP([0^0]_{14})$ was treated by the ion assisted reaction method under oxygen environment. T-peel strength tests were performed based on the procedure of ASTM D1876-95. The T-peel strength of surface-treated CFRP/aluminum composites was compared with that of untreated CFRP/aluminum composites. The results showed that the T-peel strength of surface-treated CFRP/aluminum composites was about 5.5 times higher than that of untreated CFRP/aluminum composites. SEM examination showed that the improvement of T-peel strength was attributed to the uniform spread and fracture of epoxy adhesive.

• 대한기계학회논문집A
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• 제26권11호
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• pp.2374-2382
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• 2002

Aluminum alloy/aramid fiber reinforced plastic(Al/AFRP) laminates consists of high strength metal(A15052) and laminated aramid fiber with structural adhesive bond. The mixture ratio effect of epoxy resin curing agent accelerator on the tensile strength and T-peel strength characteristic in Al AFRP laminates were investigated in this study. The epoxy. diglycidylether of bisphenol A(DCEBA), It'as cured by methylene dianiline(MDA) with or without an accelerator(K-54). Eight different kinds of resin mixture ratios were selected for the test , five kinds of Al/AFRP laminates were named as Al/AFRP(1) and three others of Al/AFRP laminates were named as Al/AFRP(2). The comparison of tensile strength and T-peel strength with variation of resin mixture ratio were studied. Respectively. Al/AFRP(1) and Al/AFRP(2) indicated approximately 6.0 times and 7.0 times more improved maximum tensile strength in comparison with those of monolithic A15052. Al/AFRP(2) indicated approximately 1.5 times more impoved maximum T-peel strengths in comparison with those of Al/AFRP(1). As results. Al/AFRP(2) turned out to have more effective characteristics on the tensile strength and T-peel strength than those of Al/AFRP(1).

• 한국안전학회지
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• 제24권3호
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• pp.7-12
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• 2009

The tensile and fatigue experiments were conducted with tensile-peel specimens for investigating on strength of adhesively bonded and mechanical press joints of aluminum sheet used in the field of the automobile industry. The combining epoxy adhesive bonding and mechanical press joining exhibits an increase in joining force as a result of interaction between static forces of the two joining methods. The fatigue strength of pure adhesive joint was measured as 91% of that of the combination of adhesive bond and mechanical press joint, suggesting that the interaction between the bonding and mechanical joining was about 9%.

• 소성∙가공
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• 제6권2호
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• pp.136-144
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• 1997

(Ag-10%Ni)/Cu clad metals for electric contact switch were fabricated by cold-roll bonding process. 2 or 3 passes of cold-rolling was carried out for each process to investigate the effect of the rolling passes on the bonding property. The effect of the annealing temperature of copper before the cold-roll bonding on the bond strength was also studied. The specimen bonded with copper annealed below 30$0^{\circ}C$ before roll bonding showed good bond strength. This is because high stored energy in copper promoted the short range diffusion and the grain refinement of copper by the static recrystallization increased the degree of the interfacial coherency. The maximum peel strength of clad metals bonded with Cu annealed below 30$0^{\circ}C$ was 120N.