A Stress-Magnetization Coupled Model for Magnetic Memory Phenomenon of Ferromagnetism Materials

A stress-magnetization coupled model which can describe the magnetic field distribution around fault effectively was constituted. Firstly, in order to better describe the complex ferromagnetism materials behavior, a new nonlinear constitutive model was developed, which could reflect the effect of residual stress on the magnetic field of magnetic ferromagnetism materials. Then, a stress-magnetization coupled model was established by integrating magnetic dipole model. The variation of magnetic field and the leakage magnetic field of damage zone had been researched and calculated respectively based on this model. An experimental equipment of petroleum pipeline with fault was established. The results of magnetic memory testing on the petroleum pipeline were in accordance with the stress-magnetization coupled model. This model could describe the magnetic field of fault, distribution of fault, the depth of fault, which can provide a reference for the quantitative analysis of magnetic signal.