CFRP composites have high specific strength, specific stiffness, long fatigue life, light weight environmental safety characteristics. In this study, the mechanical properties are investigated through the compressive simulation analysis on the carbon fiber reinforced plastic sandwich. The experiment is carried out with the same condition as the analysis to verify the analysis result. One sandwich plate is composed with four layers. From the upper, this plate has the first, second, third and fourth layers due to the arrangement of angle direction. A plate has the symbol of [0/30/30/0] as the first, second, third and fourth layers due to the angle directions of 0°, 30°, 30° and 0°. There are the plates of [0/30/30/0], [0/60/60/0] and [0/90/90/0] in this study. The maximum compressive load becomes 53.139kN during the compression time of 12 sec in case of the plate of [0/30/30/0]. The maximum compressive load becomes 61.826kN during the compression time of 12 sec in case of the plate of [0/60/60/0]. The maximum compressive load becomes 53.002kN during the compression time of 12 sec in case of the plate of [0/90/90/0]. So, the plate of [0/60/60/0] endures the most load among three plates. The result of this study can be applied practically through the validation of experimental data on the simulation data. In this study, the mechanical characteristics are examined systematically through the impact analysis on the composite material of the carbon fiber reinforced plastic with aluminum foam by using the impact absorption due to CFRP plate.

기계의 무게를 대폭 줄이는 것을 목적으로 복합재료에 대해서 많은 연구를 진행하고 있다. 본 연구에서 탄소 섬유 강화 플라스틱과 알루미늄 폼으로 조합해서 만든 샌드위치에 대해서 압축 시뮬레이션 해석을 하였다. 또한 탄소 섬유 강화 플라스틱의 섬유의 배열방식은 [0/90/90/0]이다. 시뮬레이션 해석 방법은 ANSYS를 이용하여 실제와 같은 경계조건을 주고 유한요소해석을 진행하였다. 시편을 압축하는 동안에 탄소 섬유 강화 플라스틱과 알루미늄 폼이 그 접착력보다 크게 발생되어 떨어지는 형상이 일어났다. 또한 2438.3MPa의 최대 등가응력이 발생된 것을 확인하였다. 본 연구에서 나온 해석결과는 안전설계 및 복합재료의 개발에 필요한 자료를 제공할 수 있을 것으로 사료된다.

In this study, carbon fiber reinforced plastic and aluminum foam used in impact absorber are assembled and modelled. These models are investigated by impact simulation and verified by experimental data. Impact energies of 30 J, 60 J and 100 J are applied on these specimens by striker. For example the experiment for impact energy of 30 J is done and verified by referring to analysis result. As the structural safeties of these assembled composite materials can be anticipated through this study result, these simulation analysis results can be applied into real field.

본 논문에서는 탄소 섬유 강화 플라스틱 샌드위치 복합재료의 시뮬레이션 해석을 통해 기계적 충격특 성에 대해 연구를 하였다. 스트라이커에 30 J, 60 J, 100 J의 충격에너지를 부여하여 고정 된 시험편에 충격을 가했다. 시뮬레이션 해석 방법은 ANSYS를 이용하여 실제와 같은 경계조건을 주며 유한요소해 석을 진행하였다. 그 결과는 100J의 충격에 에너지를 가해졌을 때 스트라이커가 시험편을 완전히 관통하는 모습이 보이고 충격에너지 30J과 60J일 때는 스트라이커가 시험편을 관통하지 않았다. 본 연구의 결과로 탄소 섬유 강화 플라스틱과 알루미늄 폼으로 조립한 복합재료의 구조적 안전성을 예측과 구조적 안전성이 높이는 사료가 된다.

The CFRP composite has a lot of merits such as mechanical characteristic, light and thermal resistance. For these merits, CFRP is applied to so many industrial area. In order to use the composite materials in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joints must be provided, which require precise ,machining. In this study, the specimens differentiating the stacking sequence of 5kinds were used. When drilling the carbon fiber reinforced plastics, it was checked on whether the stacking sequence reached any effect on the cutting force. Also relationship between the drill diameter is examined from the drilling experiment, which is the drilling of Fabric, Unidirectional specimen with ∅6mm, ∅10mm, ∅12mm cemented carbide drill. Considering cutting force and drilling diameter, the results are analyzed.

CFRP (Carbon Fiber Reinforced Plastic) has high tensile strength, light weight, and excellent corrosion resistance, so it is used for construction such as seismic reinforcement and explosion proof in construction area. Dynamic loads, such as earthquakes and explosions, cause rapid deformation of the material and the material behaves differently from its static condition. Therefore, in this study, tensile tests of CFRP were conducted under static and dynamic loads, and the tensile performance of was evaluated according to the strain rate.

The purpose of this research is to develop a joint system for two concrete pipes with reduced wall thickness by a carbon fiber reinforced polymer (CFRP) fabric. As compared to conventional concrete pipe, the concrete pipe with the reduced wall thickness has more flexibility. However, the reduced wall thickness makes the conventional joint system not feasible. As an alternative joint, externally wrapping system with the CFRP fabric was proposed. The two CFRP widths (75mm and 150mm) were accounted for as a variable under joint shear test from ASTM C497M specification. The externally wrapping system showed 81.07% higher shear strength, as compared to the required shear strength by ASTM C497M.