单向碳纤维复合材料分层缺陷垂直涡流检测有限元仿真研究

针对单向碳纤维复合材料分层缺陷难以检测的问题,设计了一个共面三矩形线圈探头,建立了利用该探头进行单向碳纤维复合材料分层缺陷垂直涡流检测的有限元模型,并利用该模型仿真计算了存在不同厚度分层缺陷时垂直涡流检测探头输出的感应电压信号变化情况。仿真结果表明,所设计的探头可灵敏地检测出单向碳纤维复合材料分层缺陷,并且在探头扫描检测分层缺陷的过程中,探头输出的感应电压虚部会出现成对的峰值和次峰值,峰值与分层厚度成正比,次峰值对的出现位置对应于分层缺陷边缘的位置,通过对峰值大小和次峰值对的出现位置进行分析,可以实现单向碳纤维复合材料分层缺陷厚度和范围的定量化评估,为实际工程应用提供了有价值的参考。

Finite Element Analysis of Delamination in Unidirectional Carbon Fiber Reinforced Polymer by Vertical Eddy Current Method

Aiming at the problem that the delamination defect of unidirectional carbon fiber reinforced polymer is difficult to detect,a coplanar three-rectangular coil probe is designed.The finite element model of vertical eddy current testing for delamination by using this probe was established.The model was used to simulate the variation of induced voltage output by vertical eddy current testing probe with different thickness delamination.The results show that the designed probe can sensitively detect the delamination defects,and the pair of peaks and sub-peaks will appear in the imaginary part of the induced voltage during the probe scanning to the defects.The peak value is proportional to the delamination thickness.The position of the sub-peak pair corresponds to the edge of the delamination.By analyzing the peak value and the sub-peak pair’s position,the thickness and range of delamination can be estimated,which provides valuable reference for practical engineering application.