单向CFRP表面缺陷的涡流检测与有限元仿真研究

针对目前钢制拉索耐腐蚀性差,寿命周期短,同时无法满足当前工程应用中超大跨距的要求,碳纤维复合材料因具有优异的机械性能和稳定的化学性能,为寻找替代钢拉索的新材料拉索提供了新的研究方向。本研究利用实验与数值仿真相结合的方法,开展CFRP裂纹损伤结构的涡流场分析与检测。结果表明,当激励频率为1 250 kHz时,线圈对碳纤维板索裂纹损伤检测最为敏感。裂纹处信号幅值随裂纹深度的增加而增加;随裂纹宽度的增加呈现先增加后减小的趋势,在裂纹宽度为1.5 mm时幅值达到最大值。通过CFRP涡流场有限元仿真,能够有效地验证实验结果。涡流检测技术可以有效应用在CFRP的损伤缺陷检测当中,为今后利用电磁涡流技术实现CFRP拉索的在役缺陷检测提供参考依据。

Eddy current detection and finite element simulation study of surface defects in unidirectional CFRP

In response to the poor corrosion resistance and short life cycle of the current steel cable, as well as the inability to meet the requirements of the current engineering applications of oversized spans, carbon fiber composites provide a new research direction for finding new materials to replace steel cable ties due to their excellent mechanical properties and stable chemical properties. This study uses a combination of experimental and numerical simulation to carry out the analysis and detection of eddy current fields in CFRP crack damaged structures. The results show that the coil is most sensitive to the detection of crack damage in CFRP cables when the excitation frequency is 1 250 kHz. The amplitude of the signal at the crack increases with the increase of the crack depth; it shows the trend of increasing and then decreasing with the increase of the crack width, and the amplitude reaches the maximum value when the crack width is 1.5 mm. Eddy current inspection technology can be effectively applied in the detection of damage defects in CFRP, providing a reference basis for the future use of electromagnetic eddy current technology to achieve in-service defect detection of CFRP cables.