金属构件缺陷的脉冲涡流近-远场复合定量检测
Pulsed eddy current near-remote-field hybird quantitative detection of metal component defects
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摘要: 鉴于脉冲涡流检测和脉冲远场涡流检测在金属构件损伤检测中的优势,提出一种非铁磁性金属构件缺陷的脉冲涡流近-远场复合定量检测探头。通过数值仿真,在系统分析电磁场能流密度的基础上,研究脉冲涡流近-远场检测信号特性及其对构件腐蚀减薄缺陷的响应灵敏度,剖析检测信号特征与缺陷尺寸参数间的关联规律。同时,搭建试验平台,进一步探究基于脉冲涡流近-远场复合定量检测的非铁磁性金属构件腐蚀减薄缺陷定量检测方法。仿真及试验结果表明,所提集成磁场直接和间接耦合分量的新探头构型可同时对金属构件腐蚀减薄缺陷实施脉冲涡流检测和脉冲远场涡流检测,增强了缺陷定量信息的有效拾取。Abstract: In view of the advantages of pulsed eddy current testing (PEC) and pulsed remote-field eddy current testing (PRFEC) in detection of damages in metallic components, in this paper a new probe structure was proposed for realization of the near-field and remote-field pulsed eddy current hybrid testing (NRPEC) of defects in NFCs. Through numerical simulations, based on the analysis regarding the energy density of electromagnetic field, the signal characteristics of NRPEC and its response sensitivity to wall-thinning defects were scrutinized. The correlation between the signal feature and defect sizing parameters was analyzed. In parallel, an experimental platform of NRPEC had been built up. Through a series of experiments of NRPEC, detection and quantitative evaluation of wall-thinning defects in NFCs were further investigated. It was found from simulations and experiments that the proposed probe structure integrating the measurement of direct and indirect coupling components of magnetic field was applicable for simultaneous implementation of near-field and remote-field inspection of wall-thinning defects in NFCs, enhancing extraction of quantitative information regarding the defects under non-invasive interrogation.