针对铁磁性材料(如低碳钢、低合金钢等)在长期使用中易产生缺陷或断裂而导致事故发生的问题，研究了铁磁性材料的内部结构和变化规律；采用铁磁性材料具有的逆磁致伸缩效应与法拉第电磁感应原理相结合的方法，搭建了钢板应力集中区域的检测系统。通过对弱磁信号进行转化、采集、曲线拟合等处理，可以准确直观地显示检测结果。钢板应力检测试验表明，可以实现对铁磁性材料的应力集中区域或缺陷进行检测、定位；而且应力的变化与输出电压近似呈线性关系。

For ferromagnetic materials (such as low carbon steel, low alloy steel, etc) are liable to defect or fracture in the long-term and thus to cause accidents, the internal structure of the ferromagnetic materials and change tendency are studied in the paper. By the combination of the magnetostrictive effect and Faraday principle of electromagnetic induction, a stress concentration detection system for the steel plate is built. Through weak magnetic signal conversion, acquisition, processing curve fitting, test results can be accurately and intuitively shown. Steel plate stress tests show that the system can realize detection and localization of the stress concentration regional or defects of the ferromagnetic materials; and an approximately linear relationship between the change of stress and output voltage exists.