Investigation of the variation in magnetic field induced by cyclic tensile-compressive stress

The variation of the magnetic field, induced by applied stress under the geomagnetic field, can potentially be used to evaluate the degree of fatigue damage for ferromagnetic materials. To further investigate the physical mechanism of the metal magnetic memory phenomenon, measurements of the normal components of the stress-induced magnetic field intensity, Hp(y), were performed during rotary bending fatigue experiments under the geomagnetic field. The results showed that the process of metal magnetic memory includes reversible and irreversible magnetisation. The applied cyclic tensile-compressive stress would cause magnetisation to approach anhysteretic magnetisation irreversibly. In addition, magnetisation under tensile stress was different from that under compressive stress.