• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.67-71
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• 2008

The study analyzed on fire resistance of high strength concrete followed by thickness of fireproof plaster board and change of adhesive method. In spalling characteristics after fire resistance test, all four-side covering concretes were left out of testing screens. Thus, serious spalling was happened by exposing their internal reinforcing rods. in partial testing screens, spalling was happened till the internal concrete of main reinforcing rod. Only, temperature history didn't have special differences among changes of adhesive method. However, thickness of fireproof plaster board is very important. Namely, mock member reinforcing 25mm general adhesive + Bending was 583℃ in the highest temperature of surface part and 479℃ in the highest temperature of the main reinforcing rod, which was relatively good temperature history.

• 한국재료학회지
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• 제32권10호
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• pp.442-447
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• 2022

Sealing treatment is a post-surface treatment of the plasma spray coating process to improve the corrosion resistance of the coating material. In this study, the effect of the sealing on the corrosion resistance and adhesive strength of the plasma spray-coated alumina coatings was analyzed. For sealing, an epoxy resin was applied to the surface of the coated specimen using a brush. The coated specimen was subjected to a salt spray test for up to 48 hours and microstructural analysis revealed that corrosion in the coating layer/base material interface was suppressed due to the resin sealing. Measurement of the adhesive strength of the specimens subjected to the salt spray test indicated that the adhesive strength of the sealed specimens remained higher than that of the unsealed specimens. In conclusion, the resin sealing treatment for the plasma spray-coated alumina coatings is an effective method for suppressing corrosion in the coating layer/base material interface and maintaining high adhesive strength.

• Journal of Welding and Joining
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• 제33권2호
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• pp.69-77
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• 2015

High strength steels have been continually being developed to improve in fuel economy in automotive and ensure safety of passengers. New bonding and welding methods have been required for improving weldability on high strength steels. In this study, resistance spot welding and Weld-bond with nugget diameters of 4.0mm, 5.0mm, 6.0mm and 7.0mm were produced and tested, respectively. In order to confirm the effect of nugget diameters on tensile shear characteristic of the Weld-bond, tensile shear characteristics of Weld-bond were compared with those of resistance spot welding and adhesive bonding. Peak load of Weld-bond were increased as the nugget diameter increases. After appearing maximum peak load continuous fracture followed with second peak owing to load being carried by resistance spot weldment. Fracture modes of the adhesive layer in Weld-bond fractures were represented by mixed fracture mode, which are cohesive failure on adhesive part and button failure at resistance spot welds. The results showed that the tensile shear properties can be improved by applying Weld-bond on TRIP steel, and more apparent with nugget diameter higher than 5${\surd}$t.

• 한국지진공학회논문집
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• 제19권4호
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• pp.183-194
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• 2015

In this paper, Nonlinear Static Pushover analysis method(NSP) is proposed which apply to RC buildings reinforced by external retrofit for seismic performance. Based on previous analysis and research, NSP is more developed by connection nonlinearity according to shear resistance mechanism such as dowel and adhesive resistance as major shear resistance elements. According to the proposed method, structural analysis for example buildings was carried out to evaluate seismic performance of buildings. And, it was confirmed that depending on shear strain and characteristics of joint resistant of external retrofitting are different from internal retrofitting. Furthermore, the strength reduction coefficient of the anchor needs to be considered at the joint design.

• 접착 및 계면
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• 제19권3호
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• pp.118-122
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• 2018

본 연구에서는 에스터기를 함유하는 직물 접착용 폴리우레탄 핫멜트 접착제를 합성하였다. 분자량 증가를 위하여 서로 다른 3종의 사슬 연장제를 사용하였고, 사슬연장제의 종류에 따른 분자량 변화와 접착물성 변화를 비교하였다. 사슬연장제로써1,4-부탄디올을 사용한 경우 다른 사슬연장제를 사용했을 때 보다 더 높은 박리강도를 나타내었으며, 높은 박리강도를 발휘하는 최적의 분자량이 존재함을 알게 되었다. 또한, 핫멜트 접착제를 다양한 직물 즉, 면, 폴리에스터 그리고 우레탄이 코팅된 폴리에스터에 대하여 접착시킨 후 접착력 측정과 $60^{\circ}C$ 물에 대한 내수성 실험을 수행한 결과 면직물에 대한 박리강도가 가장 큼을 보였고 우레탄 코팅된 폴리에스터 직물에 대해 가장 큰 내수성을 보였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.121-124
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• 2003

A new form-joining process with the aid of an adhesive is proposed in which an epoxy adhesive is applied to a sheet metal pair, and before it cures the pair is clinched to cause the geometric constraint in the form of a protrusion. In order to reduce the forming load and the height of protrusions, a new die and punch set with a very small clearance was devised to reduce the depth of drawing and the forming load. Taguchi method was employed to find the optimal values of design parameters. To implement each case of the orthogonal array, the finite element method was used. The experiments showed that on the tensile-shear test, the bonding strength of the new form-joining process with an epoxy adhesive is approximately the same as that of the resistance spot welding; and in comparison with the other two form-joining processes with an epoxy adhesive, the height of protrusions was reduced by more than 65 percent and the forming load by 50 percent.

• Steel and Composite Structures
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• 제43권1호
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• pp.19-30
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• 2022

The static strength and fatigue crack resistance of the aircraft skin structures depend on the materials used and joint type. Most of the commercial aircraft's skin panel structures are made from aluminium alloy and carbon fibre reinforced epoxy. In this study, the fatigue resistance of four joint configurations (metal/metal, metal/composite, composite/composite and composite/metal) with riveted, adhesive bonded, and hybrid joining techniques are investigated with experiments and finite element analysis. The fatigue tests were tension-tension because of the typical nature of the loads on aircraft skin panels susceptible of experimenting fatigue. Experiment results suggest that the fatigue life of hybrid joints is superior to adhesive bonded joints, and these in turn much better than conventional riveted joints. Thanks to the fact that, for hybrid joints, the adhesive bond provides better load distribution and ensures load-carrying capacity in the event of premature adhesive failure while rivets induce compressive residual stresses in the joint. Results from FE tool ABAQUS analysis for adhesive bonded and hybrid joints agrees with the experiments. From the analysis, the energy release rate for adhesive bonded joints is higher than that of hybrid joints in both opening (mode I) and shear direction (mode II). Most joints show higher energy release rate in mode II. This indicates that the joints experience fatigue crack in the shear direction, which is responsible for crack opening.

• Journal of Pharmaceutical Investigation
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• 제18권1호
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• pp.5-8
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• 1988

Physical properties of oral adhesive tablets prepared with four kinds of gums for topical or systemic drug delivery were investigated. Oral adhesive tablets containing 5mg of brilliant blue(BB) were prepared from direct compression. Viscosity of 2% gum solutions, water absorption, fracture resistance, stickiness of tablets, and dissolution of BB in pH 6.8 dissolution medium were tested. Acacia showed good stickiness and fracture resistance, and tragacanth showed good retarding effect on the release of BB from tablets. Therefore, tablets with varing ratios of acacia and tragacanth were prepared and their physical properties were examined. In conclusion, it was possible to obtain some adequate properties by compounding acacia and tragacanth.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 추계 학술논문 발표대회 논문집
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• pp.61-65
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• 2006

Urethane, epoxy, acrylic have common property to adhere on the concrete dried surface in the waterproofing materials at present. In the wet condition, however, the materials such as urethane, epoxy, acrylic need a long hardening time and it become a reason of water leakage as the materials breaking down. it is one of the problem to adhere to the substrate. Therefore, in this thesis, I focused to assure the structural safety and durability and quality for waterproofing and safe of construction cost by cut down the cost of labor and reduce the term of works as searching the application of field condition for hish adhesive spray type of degenerated and rubberized asphalt membrane material.

• 공업화학
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• 제33권6호
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• pp.661-665
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• 2022

In this study, 2,5-dichlorobenzophenone was synthesized as a monomer using 1,4-dichlorbenzene, and subsequently, copolymers of benzoyl-p-phenylene and p-phenylene were prepared. The average molecular weight was improved using the low-molecular-weight polymer cutting method. The average molecular weight and glass transition temperature of the synthesized polymers were estimated. The as-prepared polymer was used as a hard coating material, and the coating was conducted on a poly(methyl methacrylate) plate. Furthermore, physical properties of the coatings, such as pencil hardness, adhesive strength, and abrasion resistance, were estimated. As the amount of p-phenylene in the copolymer increased, pencil hardness and abrasion resistance improved. The amount of p-phenylene in the copolymer can be increased to 30 mol% in order to increase the hardness of the coating, and the adhesive strength was insufficient for the copolymers with p-phenylene ratio greater than 35 mol%.