Quantitative study on the triaxial characteristics of weak magnetic stress internal detection signals of pipelines based on the theory of magnetoelectric coupling

The quantitative analysis of stress concentration zone in pipelines using weak magnetic stress internal detection is quite challenging. In this study, magneto-mechanical calculations are introduced into Maxwell's equations, and a mathematical model is established for triaxial weak magnetic stress detection. This model is used to calculate and analyze the variation trend of triaxial weak magnetic signal with stress and propagation distance in the pipeline. The results indicate that weak magnetic signal has a linear relationship with the stress. As the stress increases, the weak magnetic signal is reversed, where the tensile capacity of the pipeline begins to weaken and the magneto-mechanical sensitivity decreases, but the signal recognition rate increases. The weak magnetic signal exhibits an exponential decaying trend during propagation. The axial component of weak magnetic signal has the highest signal recognition rate. The circumferential and radial components exhibit strong abilities of avoiding false detection and avoiding missed detection, respectively.