“…In fatigue tests using magnetic memory detection technology, the state parameters reflecting force include the normal component of magnetic field strength, tangential component, coercive force, etc. Researchers have established the relationship between residual magnetic field, residual stress, plastic strain, and fatigue damage degree based on these parameters in order to quantitatively evaluate the damage state of ferromagnetic materials; for example, Juraszek J presents the implementation of the method of own residual magnetic field to identify damages occurring in a steel rope [13]; Qian Z, Liu H, et al has proposed a new low-cost and efficient Residual Magnetic Scanning Measurement (RMSM) method, which can improve the accuracy of early damage assessment for ferromagnetic materials [14]; Shen Z, Chen H, et al used metal magnetic memory technology to quantitatively evaluate the residual stress of 35CrMo steel cylinder before and after heat treatment, revealed the correlation between coercive force and structural mechanics, and obtained that the structural mechanics state of 35CrMo steel cylinder can be justified by measuring its coercive force [15]; Pang C, Zhou J, et al proposed a nondestructive testing method to detect the internal tensile force of steel bars by analyzing the Self Leakage Magnetic Field (SMFL) signal based on the metal magnetic memory effect and obtained the SMFL signal parameters that can be used to quantitatively calculate the tensile force of steel bars [16]; Su S, Ma X, Wang W, et al conducted indoor experiments on S355 steel under low cycle fatigue (LCF) mode and simulated the coupling between magnetic memory signal and cumulative plastic strain using finite element method; they established a universal quantitative expression for the magnetic damage model, providing a direct method for the cumulative plastic damage of low-carbon steel under LCF [17]. In addition to the experimental conditions such as rotational bending, LCF, and tensile load carried out by the aforementioned researchers, Zhou W, Fan J C, et al also studied the fatigue damage state under pulse impact conditions; they measured magnetic memory signals during the fatigue process of X80 pipeline steel in the laboratory and analyzed the linear relationship between magnetic memory characteristic parameters and fatigue crack depth, proving that magnetic memory signals can reflect changes in fatigue damage status [18].…”