电阻法研究单向炭纤维复合材料的拉伸破坏行为

TENSILE DAMAGE BEHAVIOUR STUDY FOR CFRP COMPOSITE BY ELECTRICAL RESISTANCE MEASUREMENT

采用单向炭纤维增强树脂(简称CFRP)拉挤复合材料,通过在线检测单向CFRP复合材料在受拉伸应力作用下电阻随时间的变化,并借助扫描电镜和红外热像分析仪对复合材料的破坏行为进行观测。结果表明,CFRP复合材料在受力过程中,当拉伸速度较快时,试样的体积电阻随应力增加持续降低,在试样断裂前降至最低,但在试样断裂瞬间急剧增加;当拉伸速度较慢时,拉伸前期的电阻随应力增加不断降低,在断裂发生前电阻发生较大幅度的振荡。通过扫描电镜和红外热像无损检测技术佐证,电阻的变化可反映CFRP复合材料在拉伸过程中发生的内部结构变化,具有结构健康监控的特征。

This paper is related to in-real measurements of the electrical resistance with time during tensile loading in unidirectional carbon fiber reinforced polymer (CFRP) pull-extract composite. Simultaneously, infrared thermography non-destructive evaluation and scan electrical microscopy were used to observation the damage behaviour. Experimental results demonstrate that when the tensile speed is fast, longitudinal volume electrical resistance decreases with the increasing of the stress, before the rupture the electrical resistance decreases to the most low, the moment the sample rupture, the electrical resistance increases suddenly. when the tensile speed is slow, longitudinal volume electrical resistance decreases with the increasing of the stress during the tensile prophase, before the rupture, the big surging of the electrical resistance occurres. Scan electrical microscopy and infrared thermography analysis validate that the change of the electrical resistance can reflect the change of microdamage in the materials during the tensile test and has a structural health monitoring characteristic.