The fragmentation test using dogbone shape of single fiber composite (E-glass fiber/epoxy system) was applied in order to investigate the durability against the environment. The effect of immersion time on the interfacial shear strength was studied by means of measuring the interfacial shear strength of the specimens which were immersed in distilled water at 75℃ for a certain period of time. Water uptake increased continuously as the imversion time was increased and the critical fiber aspect ratio (L_c/D_f) increased with increasing water uptake. It was also found that the interfacial shear strength was reduced significantly with increasing the immersion time.

E-유리섬유/에폭시 수지 복합재료의 환경에 대한 내구성을 검토하기 위해 dogbone형의 단섬유(single fiber) fragmentation 시험방법을 채택하였고, 제조된 시편을 75℃의 증류수에 일정기간 침적 한 후에 섬유와 수지와의 계면전단강도를 측정함으로써 침적시간에 따른 영향을 비교 검토하였다. 그 결과, 중류수에 침적된 시편은 침적시간이 증가할수록 수분함유율은 계속적으로 증가를 보였으며, 수분흡수량의 증가에 따라 임계 aspect비도 증가하였다. 또한 침적시간이 증가할수록 계면전단강도는 감소하는 경향을 나타내었다.

Keywords: fragmentation test; interfacial shear strength; durability; aspect ratio