• Elastomers and Composites
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• 제28권4호
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• pp.274-282
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• 1993

Resorcinol-tannin-formaldehyde-latex(RTFL) adhesive was prepared to bond SBR to nylon in reinforced rubber composites. A key factor of adhesive contributes to the adhesion strength between SBR and nylon was the toughness of adhesive itself. Although the stiffness and strength of adhesive film decreased slightly with increasing level of tannin substitution for resorcinol in a standard RFL adhesive, the maximum toughness of adhesive film, which showed yield behavior and high dissipative capacity, was obtain by 60% tannin substitution. However, a marked softening and reduction in toughness occurred at sufficiently high substitution. Also, the adhesive film, which was heat-treated to simulate cure, showed higher strength than the unheated film. Thus, the properties of tannin containing adhesives could be optimized by using 40/60 weight ratio of the resorcinol/tannin in RTFL adhesive composition as well as heat treatment of adhesive film.

• Elastomers and Composites
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• 제47권4호
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• pp.297-309
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• 2012

나노보강제의 하나인 아연 메타아크릴레이트 (ZMA)로 보강된 천연고무(NR)/부타디엔고무(BR) 블랜드에 발포제 함량을 달리하여 적용하여 발포거동을 관찰하였다. ZMA 첨가에 따라 전반적인 발포고무의 물성은 향상되었지만, 발포입자크기, 밀도, 발포도 등 발포입자의 모폴로지에는 크게 영향을 미치지 않았다. 발포제의 함량에 따라 발포고무의 기계적 물성은 크게 영향을 받는 것으로 나타났다. 발포제 함량 증가에 따라 발포도가 증가하였고, 이는 발포고무의 밀도감소로 나타났지만, 발포입자의 크기나 분산성은 크게 영향을 받지 않았다. 고함량 스티렌-부타디엔 고무(HSBR)의 영향도 함께 조사하였다. HSBR 함량 증가에 따라 발포입자의 크기는 작아졌고 분산성은 향상되었다. 발포고무는 대변형에서 에너지 흡수성이 뛰어난 것으로 나타났다.

• Elastomers and Composites
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• 제50권3호
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• pp.205-209
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• 2015

Magnesium oxide (MgO) reinforced polyamide-66 (PA66) composites were prepared through melt-compounding method in order to determine the possibility of using MgO particle as conductive filler in the polymer-based composite. The effects of MgO filler content on the thermal conductivity and mechanical properties for the PA66/MgO composites were investigated. The results showed that the addition of MgO filler to the PA66 matrix led to a large increase in thermal conductivity of the PA66/MgO composites. Tensile strengths of the PA66/MgO composites were slightly decreased as MgO filler loading increased. However, flexural strength and flexural modulus were improved with increasing filler loading. Notched Izod impact strengths were dramatically lowered by the addition of MgO filler.

• 국제초고층학회논문집
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• 제10권3호
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• pp.173-178
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• 2021

In this paper we introduce Shinagawa HEART, located in Shinagawa district, Tokyo. It is a mixed-use building with residences on the upper floors, offices on the lower floors, and commercial uses on the first and second floors, and is intended to meet the various needs of a building on the border between residential and commercial areas. The upper floors of the building are made of reinforced concrete, while the middle and lower floors are made of steel with CFT columns. First, an overview of the structural plan of the building is presented. Next, the adoption of the middle layer seismic isolation and the switch between the lower steel structure and the upper reinforced concrete structure, which are the features of this building, are explained. Finally, the construction method adopted to achieve the design performance is explained.

• Elastomers and Composites
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• 제53권4호
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• pp.234-238
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• 2018

The influence of reinforcing UHMWPE powder on the tribological and mechanical properties of HDPE was investigated. The circularizing of UHMWPE powder was improved by high-speed rotation to enhance particle distribution and flowability. HDPE composites reinforced with UHMWPE powder in the range of 0-50 wt% were prepared by co-rotating twin screw extrusion. The abrasion resistance, plane friction coefficient, tensile strengths, and impact strengths of the composites were investigated as a function of the UHMWPE content. An increasing UHMWPE content decreased the plane friction coefficient and increased the abrasion resistance and impact strength. It is expected that HDPE composites reinforced with spherical UHMWPE powder particles can be used to improve the durability of products such as pipes in the future.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.383-390
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• 2000

The purpose of this paper is to investigate dynamic characteristics of an isolated bridge with a different location of seismic isolation at piers and to determine the best location of seismic isolation. The substructure of the bridge is two column framed type reinforced concrete and has relatively high piers so it has long natural period, To decide the best location of seismic isolations displacement shear force bending moment acceleration and absorbed energy are compared using fast nonlinear analysis. To isolate overall structures is effective to bending moments and shear forces for long period bridges.

• 폴리머
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• 제35권4호
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• pp.342-349
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• 2011

실리카의 표면 개질제인 vinyltriethoxysilane(VTEOS)의 함량에 따른 실리카로 보강된 실리콘 고무의 기계적 물성 변화 및 내열성, 내유성, 압축 영구줄음률, 반발탄성 및 가교밀도 변화를 연구하였다. 결과로 VTEOS의 함량이 2.0 phr까지 증가함에 따라 경도는 상승하였으나 인장강도 파단신율, 인열강도가 감소하였다. 내열시험에서는 VTEOS의 함량이 증가될수록 경도변화, 인장강도 변화율, 파단신율 변화율이 크게 감소하였다. VTEOS 2.0 phr에서 가장 우수한 내열특성을 나타내었다. 또한 VTEOS의 함량이 증가될수록 실리콘 고무의 내유성이 증진되었으며, VTEOS 미첨가 시보다 경도 하락폭이 크게 낮았으며, 파란신율 변화율은 약 2배 이상 감소하였다. 반발탄성도 VTEOS의 함량이 증가될수록 우수하였으며, 압축 영구줄음률 역시 VTEOS가 증가될수록 감소하였다. 가교실험 결과 VTEOS가 증가될수록 최대 토크값와 가교밀도가 크게 향상되었다.

• International Journal of Precision Engineering and Manufacturing
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• 제8권4호
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• pp.38-44
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• 2007

Combat vehicles are frequently maneuvered in battlefields when the lives of combatants are being threatened. These vehicles are important elements that influence the consequences of a battle. Their armor must be lightweight and provide excellent protection to ensure successful operations. Ceramic composite armor has recently been developed by many countries to fulfill these requirements. We reviewed previous research to determine an effective armor design, and then fabricated a composite armor structure using $Al_2O_3$ and glass fiber-reinforced polymer. Specimens were manufactured under controlled conditions using different backing plate thicknesses and bonding methods for the ceramic layer and the backing plate. The penetration of an armor-piercing bullet was evaluated from ballistic protection tests. The bonding method between the ceramic layer and the fiber-reinforced polymer influenced the ballistic protection performance. A bonding layer using rubber provided the best protection.

• 한국농공학회논문집
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• 제59권5호
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• pp.73-81
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• 2017

The improved movable weir supplements the advantages and disadvantages of the rubber weir and the conduction gate. It consists of a stainless steel gate, air bags, and a steel clamping plate. The stainless steel gate is the main body of the weir, and the inflatable rubber sheet serves to support the steel gate. The steel clamping plate is typically in direct continuous contact with water, but this leads to corrosion issues that can reduce the life of the entire movable weir. In this study, a panel-type glass-fiber-reinforced polymer (GFRP) clamping plate was designed and fabricated. The test results showed that the flexural load of the panel-type GFRP composite clamping plate was over twice that of the wings type GFRP clamping plate. The lowest moisture absorption value was obtained upon exposure to tap water, and exposure to other solutions showed similar values. Additionally, flexural load testing after exposure to an accelerated environment found the lowest residual loads of 80.51 % and 78.50 % at 50 and 100 days, respectively, for exposure to a $CaCl_2$ solution, while exposure to other environments showed residual failure loads of over 80 % at both 50 and 100 days.

• Elastomers and Composites
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• 제40권2호
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• pp.112-118
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• 2005

실란 커플링제가 카본블랙과 점토로 보강된 천연 고무 가황물의 회복 특성에 미치는 영향에 대해 연구하였다. Bis-(3-(triethoxysilyl)-propyl)-tetrasulfide (TESPT)를 실란 커플링제로 사용하였다. 실란 커플링제가 함유된 가황물은 실란 커플링제가 함유되지 않은 가황물에 비해 전반적으로 빠른 회복 거동을 보였다. 그러나, 점토 함량이 높은 가황물의 경우 $-20^{\circ}C$보다 낮은 온도에서는 실란 커플링제가 함유된 가황물이 실란 커플링제가 함유되지 않은 가황물에 비해 느리게 회복되었다. 실란 커플링제가 함유된 가황물과 실란 커플링제가 함유되지 않은 가황물의 회복량 차이는 점토 함량이 증가할수록 감소하였다. 실험 결과는 가교 밀도, 모둘러스, 그리고 결합 고무량으로 설명하였다.