• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.29-32
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• 2002

The mechanical and thermal properties of spun carbon fabric/continuous carbon fabric interplay hybrid composite materials have been studied. The properties of the hybrid composites are compared with those of the continuous carbon fabric/phenolic composites and spun carbon fabric /phenolic composites. Through hybridization, tensile strength and flexural strength of hybrid composites were increased by about 17%, and 10%, respectively compared with spun carbon composites. The thermal conductivity of the hybrid composite is lower approximately 4~6% along the direction parallel to the laminar plane than that of the continuous carbon/phenolic composite.

• Composites Research
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• v.20 no.4
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• pp.18-24
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• 2007

The mechanical and thermal properties of PAN-based/rayon-based carbon fabrics interply hybrid composite materials have been studied. Mechanical properties including tensile and interlaminar shear strengths were improved with increasing amount of continuous PAN-based carbon fabrics. The erosion rate and insulation index were determined through the torch test. Continuous rayon-based carbon fabrics composite indicated relatively low ablation resistant property. The thermal conductivity of hybrid composite of spun PAN-based/continuous rayon-based carbon fabrics is lower than that of the continuous PAN-based carbon fabrics composite.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.107-110
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• 2005

Tribological behaviors of carbon epoxy composites whose surfaces have many small grooves were compared with respect to coating method under dry sliding and water lubricating conditions. The surface coating materials were epoxy (Ep) and polyethylene (PE) mixed with self-lubricating $MoS_2$ and PTFE powders. The wear morphology of the composites observed with a scanning electron microscopic (SEM) revealed that the surface coating layer mixed with the self-lubricating powder on the grooved surface significantly improved the wear resistance under water lubricating condition because the surface coating layer blocked water to penetrate the composite surface and the self-lubricating powder reduced the wear on the coating by suppressing the generation of blisters.

• Korean Journal of Materials Research
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• v.6 no.10
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• pp.986-990
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• 1996

본 논문에서는 정속마찰 시험기를 사용하여 공기중에서 핏치/CVI계와 페놀/CVI계 낱소/탄소 복합재료의 마찰특성을 평가하고 상호 비교하였다. 운용조건(마찰거리, 마찰속도, 마찰압력)에 관계없이 페놀/CVI계의 평균 마찰계수가 핏치/CVI계 보다 높은 값을 나타내었다. 마찰거리가 4Km이하 일때는 평균 마찰계수가 불안정한 경향을 나타내고 그 이후에서는 안정한 평균 마찰계수 값을 갖는다. 또한 마찰속도와 마찰압력이 증가할수록 평균 마찰계수는 감소하는 경향을 나타내며, 페놀/CVI계의 평균 마찰계수가 핏치/CVI계 보다 높고 마찰면 온도 상승률과 최대 마찰면 온도도 높다. 마찰계수는 마찰면 온도의 영향을 받으며, 마찰속도와 3kg/$\textrm{cm}^2$이하에서 마찰압력이 커질수록 최대 마찰계수를 갖는 마찰면 온도는 높아진다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.215-219
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• 2003

Buckling and post-buckling Analysis of Ludwick type and modified Ludwick type elastic materials was carried out. Because the constitutive equation, or stress-strain relationship is different from that of linear elastic one, a new governing equation was derived and solved by $4^{th}$ order Runge-Kutta method. Considered as a special case of combined loading, the buckling under both point and distributed load was selected and researched. The final solution takes distinguished behavior whether the constitutive relation is chosen to be modified or non-modified Ludwick type as well as linear or non-linear. We also derived strain energy function for non-linear elastic constitutive relationship. By doing so, we calculated the criterion function which estimates the stability of the equilibrium solutions and determines critical buckling load for non-linear cases. We applied this theory to the constitutive relationship of fabric, which also is the non-linear equation between the applied moment and curvature. This results has both technical and mathematical significance.