Study on degradation mechanism of long-term strength of carbon fiber reinforced plastics under wet condition

研究了吸水率对单向碳纤维增强复合材料温度相关强度的影响。单向CFRP在两种条件下进行处理;干和湿。在不同的温度下，在单一的加载速率单向碳纤维增强塑料的典型的四个方向的强度进行了测试干和湿标本。四个方向分别是纵向拉伸和弯曲，横向弯曲和压缩。基于时间-温度叠加原理，采用加速试验方法评价了吸水率对树脂长期耐久性的影响，该原理适用于基体树脂的粘弹性行为。结果表明，单向CFRP在这4个方向上的长期耐久性均随温度和吸水率的增加而降低，这在很大程度上取决于基体树脂的粘弹性行为和破坏机理。

The influence of water absorption on temperature dependent strength of unidirectional CFRP was studied. Unidirectional CFRP were treated under the two conditions; Dry and Wet. The strengths for typical four directions of unidirectional CFRP were measured under various temperatures at a single loading rate for Dry and Wet specimens. The four directions were longitudinal tension and bending, transverse bending and compression, respectively. The influence of water absorption on long-term durability was evaluated by accelerated testing methodology based on the time-temperature superposition principle which holds for the vescoelastic behavior of matrix resin. As results, it can be clarified that the long-term durability in these four directions of unidirectional CFRP decrease with an increase in temperature and water absorption and that strongly depends on the viscoelastic behavior of matrix resin and the failure mechanism.