摘要
针对涡流探头对导电材料的表面和内部裂纹检测能力的不足,基于脉冲涡流检测技术设计了柔性平面差分探头,结合脉冲涡流检测的宽频谱和柔性平面差分线圈高信噪比的特点,可以在较大提离下检测表面缺陷以及检测更大埋深的内部缺陷。对铝试件表面及内部缺陷检测进行了仿真与试验研究。仿真结果表明柔性平面探头产生的涡流能够有效渗透至试件底部,缺陷造成的涡流扰动产生时间随缺陷深度增加而增大。检测信号的电压峰值大小与峰值时间仍可用于识别缺陷深度,时间剖面曲线的正负相反峰波形信号特征可用于识别裂纹。实验结果表明柔性平面探头能够检测8.55 mm提离下的表面裂纹以及无提离下埋深4.8 mm的内部裂纹。同时,检测电压信号峰值对不同试件的裂纹深度进行定量,仿真与试验结果一致。
In view of the insufficient ability of eddy current probe to detect the surface and buried defects of conductive materials,a flexible planar differential probe based on pulsed eddy current testing(PECT)was designed.Combined with the wide frequency spectrum of pulsed eddy current testing and high signal-to-noise ratio of flexible planar differential coils,the probe can detect buried defects with larger depth and surface defects with large lift-off.The surface and internal defect detection of aluminum specimen was simulated and tested.The simulation results show that the eddy current generated by the flexible planar probe can effectively penetrate into the bottom of the specimen,and the time of eddy current disturbance caused by defects increases with the increase of defect depth.The peak voltage and peak time of the detected signal can still be used to identify the defect depth.The positive and negative opposite peak waveform characteristics of the time profile curve can be used to identify cracks.The experimental results show that the flexible planar probe can detect the surface crack of 8.55 mm lift-off and the internal crack of 4.8 mm buried depth without lift-off.At the same time,the peak value of voltage signal is detected to quantify the crack depth of different specimens,and the simulation results are consistent with the experimental results.
作者
杨冉
翟国富
徐博
蒋川流
YANG Ran;ZHAI Guo-fu;XU Bo;JIANG Chuan-liu(The Reliability Institute for Electric Apparatus and Electronics,Harbin Institute of Technology,Harbin 150001,China)
出处
《仪表技术与传感器》
CSCD
北大核心
2022年第10期1-5,共5页
Instrument Technique and Sensor
关键词
脉冲涡流
柔性平面线圈
缺陷检测
深度定量
pulsed eddy current
flexible planar coils
defect detecting
depth calculation
