We have investigated the behavior of moisture absorption by an unidirectional CF/epoxy composite stored in a chamber, which could separately control temperature and humidity in air, and also examined the effect of moisture on the dynamic viscoelastic behavior of CFRP. The moisture absorption behavior was confirmed to obey the Fick's law of diffusion. The dynamic viscoelasticity of moistened specimen generally shifted to that at lower temperature, as a plasticisation effect of absorbed water. The glass transition temperature (T_g) of CFRP was lowered with increasing water content, and the reduction in T_g of moistened specimen was always greater than that of water-soaked specimen. The time-moisture superposition was confirmed to hold in air at various relative humidities at 60°C.
展开▼