单向碳纤维增强塑料的温敏效应

Temperature Sensitivity of Unidirectional Carbon Fiber Reinforced Plastics

通过升温实验考察了单向碳纤维增强塑料(CFRP)的温度敏感性,并提出一种利用该效应进行CFRP加固结构温度自监测的方法。结果表明,在恒定温度下,单向CFRP具有稳定的伏安特性;在15~60℃的升温过程中,其纵向电阻先表现出PTC效应(电阻随温度升高而增大),后表现出NTC效应(电阻随温度升高而减小),横向电阻一直表现出NTC效应,且响应曲线线性稳定,因而更适用于温度传感,其温度敏感系数为-0.000 253℃^(-1);当CFRP加固在混凝土结构上时,由于混凝土结构对CFRP加固层的热变形的制约,其NTC效应得到增强。

Temperature sensitivity of unidirectional carbon fiber reinforced plastics （CFRP） was studied by temperature raising experiments, and a temperature self-monitoring method for CFRP strengthened structure was put forward with the application of this sensitivity. The results reveal that stable voltage-current characteristic was found in unidirectional CFRP at constant temperature. And in the heating process of 15 ~ 60 ~C, the longitudinal resistance exhibits firstly a PTC （positive temperature coefficient） effect and then a NTC （negative temperature coefficient） effect, correspondingly, a linear and stable NTC effect was observed with the temperature sensitive coefficient of-O. 000 253 ~C-1 in transverse resistance. Therefore, the NTC effect of transverse resistance is more suitable for temperature sensing. The NTC effect of CFRP covering the concrete structure is enhanced due to the concrete structural restriction on the CFRP thermal deformation.