• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.389-396
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• 2002

Engineers should be careful in the design of bonding piles into pile caps because they are weak points in the pile foundation. Therefore in this study, the mechanism of bonding piles into pile caps was explained, and the design method of the composite bonding method was proposed. And the proposed design method was verified in comparison with the result of the full scale test. Also, the characteristic for the bearing capacity and the mechanism of compressive load of bonding method were analyzed.

• 한국방재학회 논문집
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• 제8권5호
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• pp.7-13
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• 2008

본 논문은 염해에 의한 부착성능 저하에 따른 철근-콘크리트 국부 비부착 구간 변화에 따른 보의 휨 실험 및 해석적 연구이다. RC보의 휨 실험 및 해석적 연구를 통하여 부착강도 및 부식정도에 대한 휨 강성을 평가, 분석하였다. 철근부식에 따른 국부적 부착손상 구간을 표현하기위하여 본 연구에서는 고무호스를 이용한 비부착 구간 모사 시험체를 제작, 염해에 의한 철근콘크리트 보의 국부 부식구간을 표현하였고 이에 대한 휨 성능을 평가하였다. 해석적 연구에서는 상용해석프로그램을 이용한 성능평가와 균열해석을 수행하여 국부적 부착구간 변화에 따른 균열 폭, 균열깊이, 위치를 파악함으로써 실제 실험결과와의 균열 확산을 예측, 비교하였다. 본 연구의 부식정도 및 국부적 비부착 구간 확대에 따른 실험적, 해석적 철근부식-강성변화율은 향후 노후 철근콘크리트 구조물의 국부적 손상 모델의 개발 및 평가에 있어 기초자료로 활용될 수 있을 것이다.

• Asian Journal for Public Opinion Research
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• 제3권1호
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• pp.1-21
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• 2015

A recent public opinion survey found that the anti-corporate sentiment of South Korean citizens is primarily due to the misbehavior of Korean corporations. South Korean citizens' skepticism of corporations may hinder the democratic and economic development of the country. As a driving force for community development, social capital is considered to enable citizens to collaborate with one another to resolve a shared problem. Specifically, this study pays attention to the relationship among social capital, corporate capacity, and trust, which may perhaps contribute to developing a democratic environment in Korean society. The study aims to explore whether Korean citizens' perceived corporate bonding and bridging social capital affect corporate capacity for collaborative action and trust in corporations. A Web survey of 385 South Koreans was conducted. The findings show that perceived bonding social capital among employees is positively related to corporate capacity for collaboration action. Moreover, perceived bonding among employees and bridging social capital between employees and local residents are positively related to corporate capacity for collaboration action and trust in corporations. These findings suggest that researchers and practitioners for organizational development and community-building need to enhance corporate social capital.

• 복합신소재구조학회 논문집
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• 제6권4호
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• pp.30-37
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• 2015

iFLASH System is new structural floor system which consists of sandwich panels filled with nano-composite. The nano-composite has low specific gravity and high bonding strength with steel plates. The bonding strength is one of important factors for structural performance of iFLASH System and it can further be improved by surface preparation such as blast metal cleaning. However, using none blast steel plates is recommended since surface preparation generates additional fabrication time and cost. In this study, a bonding strength test and bending experiment were conducted to check feasibility of applying none blast steel plates to iFLASH System. Moreover, stress in bonding plane between steel plates and nano-composite was analytically evaluated by finite element method. Consequently, flexural capacity of the specimen was 11% higher than theoretically calibrated value and its flexural behavior was structurally efficient without defect of bonding.

• 한국전기전자재료학회논문지
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• 제23권1호
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• pp.29-33
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• 2010

As the demands for the higher data transmission speed and capacity as well as integration density grow throughout the network, much works have being done in order to integrate the Electrical PCB with Optical PCB. However, one of the most troublesome problems in the commercial bonding process is to need the high temperature for the bonding. Due to the high temperature bonding process, lots of side problems are followed such as warpage and crack, etc. In this paper, we tried to develop the new bonding technology with low temperature around $100^{\circ}C$. As a result of this study, the PCB bonding technology with high bonding strength is demonstrated with the value of bonding strength from 7 to 8 MPa at the temperature of $100^{\circ}C$.

• 한국안전학회지
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• 제27권2호
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• pp.78-83
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• 2012

This is a study to confirm how to improve and substitute the existing re-bar with other material such as a fiber rope, especially super fiber rope having much more strong tensile strength. 6(b) different fiber rope reinforced beam with a section of $20{\times}30cm$ have been made and tasted as variables designed in the study. The larger diameter of fiber rope, the more capacity of the beam, even though fiber reinforced beam are increased with ten(10)percent, each. Lower capacity of fiber-reinforced beam than normal RC beam has been analyzed theoretically and empirically, based on a lot of experiences of the same size beam test. Fiber rope-reinforced concrete beam does not have sufficient capacity than RC beam due to insufficient bonding capacity of fiber rope in concrete. It leads to decrease beam bearing capacity and crack around lower center of the beam. Therefore, bonding reinforcement of fiber rope beam such as pinning a triangles steel pin in each knot of fiber rope contributes to improving bearing capacity of fiber rope reinforcing beam.

• 소성∙가공
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• 제28권1호
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• pp.15-20
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• 2019

The superplastic forming/diffusion bonding process has been developed to fabricate a core frame structure with joint nodes out of tubes, for the development of a titanium high performance bicycle. The hydroforming process has been applied for bulging of a tube in the superplastic condition before, and during the diffusion bonding process. In this experiment, a commercial Ti-3Al-2.5V tube was selected as raw material for the study. The forming experiment has been performed using a servo-hydraulic press with a capacity of 200 ton. Next, nitrogen gas was used to acquire necessary pressure for the bulging and bonding of the tubes to fabricate the joint nodes. The pertinent processing temperature was $870^{\circ}C$ for the superplastic hydroforming/diffusion bonding (SHF/DB) process, using the Ti-3Al-2.5V tube. The bonding quality and the progress of bulging and diffusion bonding have been observed by the investigation of the joining interfaces at the cross section of the joint structure. The control of the nitrogen pressure throughout the SHF/DB process, was an important factor to avoid any significant defects in the joint structure. The whole progress stage of the diffusion bonding could be observed at a joint interface. A core structure with 5 joint nodes to manufacture a titanium bicycle could be obtained in a SHF/DB process.

• Steel and Composite Structures
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• 제19권3호
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• pp.735-757
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• 2015

Composite bonding steel plate (CBSP) is a newly developed type of structure strengthened technique applicable to the existing RC beam. This composite structure is applicable to strengthening the existing beam bearing high load. The strengthened beam consists of two layers of epoxy bonding prestressed steel plates and the RC beam sandwiched in between. The bonding enclosed and prestressed U-shaped steel jackets are applied at the beam sides. This technique is adopted in case of structures with high longitudinal reinforcing bar ratio and impracticable unloading. The prestress can be generated on the strengthening steel plates and jackets by using the CBSP technique before loading. The test results of full-scale CBSP strengthened beams show that the strength and stiffness are enhanced without reduction of their ductility. It is demonstrated that the strain hysteresis effect can be effectively overcome after prestressing on the steel plates by using such technique. The applied plates and jackets can jointly behave together with the existing beam under the action of epoxy bonding and the mechanical anchorage of the steel jackets. The simplified formulas are proposed to calculate the prestress and the ultimate capacities of strengthened beams. The accuracy of formulas was verified with the experimental results.

• 한국초전도ㆍ저온공학회논문지
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• 제1권2호
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• pp.1-7
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• 1999

we evaluated the effects of joining process such as contact method. shape of joined area and pressure on the electrical and mechanical properties of Bi-2223 superconducting tape, Specifically. the current capacity of the jointed tape was measured as a function of uniaxial pressure. and the thermal shock, bonding strength and the thermal of the tape were evaluated and correlated to the microstructural evolution. It was observed that the current capacity was significanrly dependent on the uniaxial pressure The jointed tape, fabricated with a pressure of 1,000-1,600 Mpa. showed the highest value of current capacity results from improvements in core density, contacting area and grain alignment, ect. In addition, the strength of jointed tape was measured to be 86 Mpa, which is about 88% of the unjoined ape's strength. The irreversible strain($\varepsilon$irrev) for the jointed tape was measured to be 0.1%, smaller than that of unjoined tape ($\varepsilon$irrev= 0.3%). The decrease in the strength and irreversible strain for jointed tape is believed to be due to the irregular geometry/morphology of the transition area of the tape.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.183-190
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• 2006

Generally, application of steel pile as deep foundation member needs specials requirement for the connection method between steel pipe and concrete footing. To investigate real compressive behavior of connection member between steel pipe pile and concrete footing, three specimens were tested with carefully designed experimental system. Main test variable is the connection method between steel pipe pile and concrete footing. The bolted bonding method and hook bonding method was considered as the connection method in this study. From the test results gained from experiment, it was conformed that two types of connection method have the almost same compressive resistance capacity. Therefore, we can conclude that these two connection methods can be used as the strengthening method to verify the compressive composite action of concrete and steel pipe pile.