• 한국염색가공학회지
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• 제35권1호
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• pp.29-41
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• 2023

This study is about a hybrid lightweight cowl crossbeam structure with high rigidity and ability to absorb collision energy to support the cockpit module, which is an automobile interior part, and to absorb energy during a collision. It is a manufacturing process in which composite material bracket parts are inserted and injected into existing steel bars. When considering the mounting condition of a vehicle, the optimization of the fastening condition of the two parts and the mechanical properties of the composite material is acting as an important factor. Therefore, this study is about a composite material having a volume content of Polyamide(PA) and Glass Fiber used as a composite material for a composite material-metal hybrid cowl crossbeam. As a result of analyzing the physical properties of the PA/GF composite material, experimental data were obtained that can further enhance tensile strength and flexural strength by using PA66 rather than PA6 used as a base material for the composite material. And based on this, it contributed to securing the advantage of lightening by using high-stiffness composite material by improving the high disadvantage of the weight of the cowl crossbeam material, which was made only of existing metal materials.

• Advanced Composite Materials
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• 제17권3호
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• pp.225-233
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• 2008

The analysis in this paper is focused on the pattern of mixing of filaments over a cross-section of hybrid yarns according to different combinations of reinforcement and matrix filament yarns through microscopic view. The volume content of filament in hybrid yarn cross-section was maintained at 50% for both reinforcement and matrix, and the hybrid yarns count at 600 tex throughout the experiments. It was observed from the experiments that diameters of reinforcement and matrix filaments have strong effects particularly on the pattern of mixing of filaments over a cross-section of hybrid yarns such that the hybrid yarns with more or less equal diameters of reinforcement and matrix filaments showed considerably even distributions over the hybrid yarn cross-section. This paper also investigates the possibility of hybridizing carbon/aramid, carbon/glass and aramid/glass matrices through the commingling process. In the experiment, several process parameters were selected and they include pressure, yarn oversupply-rate and different nozzle types. As a result of these experiments, it was concluded that the hybridized materials show better performance than individual reinforced filament yarns in terms of mechanical properties. For small tensile forces, the carbon/glass/matrix combination turned out to be good enough for general purpose applications.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.48-52
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• 2002

This paper describes the need for a ductile Fiber Reinforced Plastic(FRP) reinforcement for Concrete Structures. Using the material hybrid and geometric hybrid, it is demonstrated that the pseudo-ductility Characteristic can be generated in FRP rebar. Ductile hybrid FRP bars were successfully fabricated at Ø3mm and Ø10mm nominal diameters using the braidtrusion process. Tensile and bending specimens from these bars were tested and compared with behavior of stress-strain of steel bar and GFRP rebar

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.84-87
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• 2000

Square tubes used for vehicle structure components have an important role on keeping its stiffness and preserving occupant safety in vehicle collision and rollover in which it experience axial collapse, bending collapse or both. Bending collapse, which absorbs kinetic energy of the impact and retains a survival space for the occupant, is a dominant failure mode in oblique collision and rollover. Thus, in this paper, the bending collapse characteristics such as the maximum bending moment and energy absorption capacity of the square tube replaced by light-weight material were evaluated and presented. The bending test of cantilever tubes which were fabricated with aluminum, GFRP and aluminum/ GFRP hybrid by co-curing process was performed. Then the maximum bending moment and the energy absorption capacity from the moment-angle curve were evaluated. Based on the test results, it was found that aluminum/ GFRP hybrid tube can show better specific energy absorption capacity compared to the pure aluminum or GFRP tube and can convert unstable collapse mode which may occur in pure GFRP tube to stable collapse mode like a aluminum tube in which plastic hinge is developed.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.143-146
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• 2002

Mg alloy is the lightest material of structural materials and is noticed for lightweight automotive parts because of excellent castability, superior ductility and damping capacity than Al alloy. But Mg Alloy is poor corrosion resistance and high temperature creep properties. In this study, Mg Matrix Composites were fabricated by squeeze casting method to improve high temperature creep properties and damping capacity. Hybrid Mg composites reinforced with Alborex, graphite particle, and SiCp was improved creep properties and damping capacity compared with Mg alloy. Compared to the length ($9\mu\textrm{m}, 27\mu\textrm{m}, 45\mu\textrm{m} etc.$), Hybrid Mg composites reinforced with SiCp, one of the most superior of the length and Alborex were more superior than those reinforced with graphite particle and Alborex in mechanical properties, creep characteristics, and damping capacity, etc.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.106-109
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• 2000

Impact tester was build up to evaluate the characterization of CFRP laminate plates under the low velocity impact. The tests were conducted on several laminates of different ply orientation A system was budded for the impact strength of CFRP laminates in consideration of stress wave propagation theory using drop-weight impact tester as one of impact test. Results indicate that absorbed energy of quasi-isotropic specimen having four interfaces is higher than that of orthotropic laminates with two interfaces. Also the damage area was measured with ultrasonic C-scanner on some samples. In the specimens the relationship was linear between damaged area and absorbed energy to some degree. Absorbed energy in the specimen that ply number, interface number and fiber stacking sequences is same but having hybrid is higher than that of orthotropic laminates without hybrid.

• Composites Research
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• 제26권4호
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• pp.223-229
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• 2013

본 연구에서는 자동차가 불규칙한 노면을 주행 시 받게 되는 충격으로 인하여 마운트 상단에 발생하는 영구변형을 방지하고자 하이브리드 복합재료를 사용한 스트럿 타워를 설계하였다. 타이어와 현가장치에서 흡수 가능한 에너지량을 초과하였을 시 잔류 충격은 마운트로 전이되며, 특히 고속주행성능을 향상시키기 위하여 강직한 현가장치를 도입한 경우, 에너지 흡수량 저하로 인하여 기존의 스트럿 타워가 쉽게 변형될 수 있다. 유한요소해석을 통하여 압연강판과 탄소섬유 복합재료로 이루어진 하이브리드 복합재료 스트럿 타워의 최적설계를 진행하였으며, 낙하충격시험을 실시하여 동적 거동을 연구하였다. 또한 3차원 형상측정과 초음파 비파괴 검사방법을 이용하여 스트럿 타워의 손상 유무를 확인하였다.

• 연구논문집
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• 통권26호
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• pp.103-112
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• 1996

$Al_2O_3/SiC$ Hybrid-Composite이 일반적인 분말공정에 의하여 제조되었다. 소결시 $\gamma-Al_2O_3에서 $\alpha-Al_2O_3$로의 전이에 seed역할을 하는 $\alpha-Al_2O_3의 첨가는 균일한 미세구조를 발달시켜 강도의 증진을 가져왔다. nano size의 SiC의 첨가는 $Al_2O_3$의 소결성과 입성장에 영향을 미쳐 파괴강도의 증진을 가져왔다. $Al_2O_3/SiC$ nano-Composite에 SiC plates의 첨가는 파괴강도의 감소를 가져왔지만, 상대적으로 파괴인성은 증진되었다. SiC plates에 nitride (BN, $Si_3N_4$ 코팅을 할 경우 crack deflection을 더욱 유발하여 파괴인성이 증진되었다.

• Composites Research
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• 제33권3호
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• pp.140-146
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• 2020

본 논문은 차량에 사용되는 파티션 패널을 기존의 알루미늄 소재에서 Carbon Fiber Reinforced Plastics(CFRP)로 소재를 변경하여 경량화 가능성을 확인하는 것을 목적으로 한다. 복합재 제작에는 3가지 방법의 직조 방법(평직, 능직, 주자직)이 사용되었고, 복합재 시편을 제작하고 시험을 수행하여 물성을 도출하였다. 이를 통해 비틀림 조건에 대한 복합재 파티션 패널 해석 모델을 구성하고, Tsai-Hill 파손 기준에 따라 구조적 안정성과 시스템 강성을 평가하였다. 섬유 배향 각도와 적층 순서에 대한 설계변수를 통해, 진화론적 알고리즘을 수행하였고, 그 결과로 최적의 복합재 파티션 패널을 설계하였다. 또한, 강도 및 비강성에 대한 구조해석 결과를 기존의 알루미늄 파티션 패널과 복합재 파티션 패널를 비교하여, 경량화 가능성을 검증하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.9-12
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• 2004

Presented is a preliminary design concept of the carbon-glass hybrid composite rebars for the application in the construction field. A glass fiber rod with indentation is used for the core of the rebar. Carbon fibers are placed over the glass core by pultrusion. To increase the mechanical locking force and bonding surface, carbon filament windings are added in the hoop direction over the carbon face. Finite element analysis and test were conducted to evaluate the effective stiffness and strength of the rods. The results show that the effective axial stiffness of the rebar with indentation are about $50\%$ of the straight rebar.