通电过程中单向连续CFRP的暂态效应

TRANSIENT EFFECT OF UNIDIRECTIONAL CONTINUOUS CFRP IN ELECTRIFYING

采用不同大小的激励电流,研究了单向连续碳纤维增强塑料(CFRP)从通电初期到稳定阶段的电压响应规律。结果表明,当激励电流≥300 m A时,在通电初期,试样的电阻急剧减小,当通电时间达到100 s左右后,电阻逐渐趋于稳定。激励电流越大,其加载初期的电阻变化速度越快,其稳定状态下的电阻变化量也越大。在通电过程中CFRP试样的温度逐渐上升,其温度变化曲线形状与电阻的暂态响应曲线形状基本相同,稳定状态下的温升随着激励电流的增大而增大。实验结果揭示了通电发热所引起的温敏效应是形成CFRP暂态响应的主要原因。

The voltage response of unidirectional continuous carbon fiber reinforced plastics（ CFRP） in electrifying to stable stage was studied with different flowing currents. In the case of current greater than or equal to 300 m A,the resistance of the CFRP specimen was found to decrease dramatically initially and become stable gradually after 100 s. The greater the current is,the more quickly the resistance varies in the initial stage and the greater the resistance change is in the stable stage. The temperature of CFRP increases gradually and the temperature curve is similar to transient response curve. In addition,the temperature change in the stable stage also increases with the increase of the current. The results reveal that transient effect of unidirectional continuous CFRP is mainly caused by the temperature sensitive response due to the ohmic heating. Based on the experimental results,for the purpose of accurately measuring the resistance change,a few suggestions were made on the applications of CFRP as piezoresistive sensors.