交流电磁场裂纹检测反演算法研究

在交流电磁场裂纹检测的仿真研究和信号分析的基础上，给出了分析磁场信号分布的数学模型，确定了用于裂纹尺寸反演研究的信号特征量。通过对不同尺寸的任意形状裂纹电磁场分布情况的数值模拟计算，总结出描述磁场分布与裂纹尺寸形状之间关系的三条规律，进而提出了一种交流电磁场检测裂纹量化算法，并利用该算法对一组交流电磁场检测试验信号进行了裂纹尺寸反演。结果表明，该算法的量化误差不超过10％，能够满足工程需要，而且该算法简单易行，计算速度快，适合于工程结构在线检测中对裂纹的实时量化。

Study on the Inversion Algorithm of Crack-sizing Based on the Alternating Current Field Measurement

Based on the numerical simulation study and signal analysis of the Alternating Current Field Measurement(ACFM),a mathematical model was presented to analyze the electromagnetic field distribution and the characteristic vectors were picked up among those disturbing electromagnetic signals.Three rules were summed up by the numerical simulation calculation of electromagnetic field around various cracks,which described the relationship between the magnetic field distribution and the size of crack.On the basis of the three rules,a crack-sizing inversion algorithm of ACFM was proposed.And actual experimental signals was processed by the algorithm.The results show that the quantitative error of the crack-sizing inversion algorithm is less than 10%,which can meet engineering expectations,and it is suitable to size crack in the real-time test of engineering structures for its simpleness and quick count velocity.