摘要
本研究采用有限元仿真和实验方法,探究了柔性差测量分形科赫涡流传感器在不同激励频率下随着提离距离增加对裂纹检测性能的演化规律,以及传感器在可检测到裂纹时的最大提离距离.随着提离距离的增加,感应涡流的分布形状发生变化,导致激励线圈形状的相似性降低,感应涡流的分布范围扩展,最终导致输出信号的强度减弱.实验结果显示,当激励频率分别为10 kHz、20 kHz、50 kHz、100 kHz、200kHz、500kHz和1 000 kHz时,传感器输出信号的实部在检测到裂纹时的最大提离距离分别为 5.0 mm、7.0 mm、8.0 mm、8.0 mm、8.0 mm、6.5 mm和 4.0 mm;虚部则分别为 6.5 mm、6.5 mm、7.5 mm、5.5 mm、8.0 mm、6.5 mm 和 6.5 mm.
Abstract
This study utilized finite element simulation and experimental methods to investigate the evolution of crack detection performance of a flexible differential fractal Koch eddy current probe at different excitation frequencies as the lift-off distance increases.As the lift-off distance increased,the distribution shape of induced eddy currents changed,leading to reduced similarity in the shape of the excitation coil and an expanded distribution range of induced eddy currents,ultimately resulting in weakened output signal strength.The experimental results showed that for excitation frequencies of 10 kHz,20 kHz,50 kHz,100 kHz,200 kHz,500 kHz,and1000kHz,the maximum lift distances of the real part of the output signal when cracks were detected were 5.0 mm,7.0 mm,8.0 mm,8.0 mm,8.0 mm,6.5 mm,and 4.0 mm,respectively.The imaginary parts were 6.5 mm,6.5 mm,7.5 mm,5.5 mm,8.0 mm,6.5 mm,and 6.5 mm,respectively.
万方数据