Numerical analysis of the magnetomechanical effect in heating pipelines

We considered a physico-mathematical model which allows to explore the possibilities of the utilization of the «magnetic memory of metals» effect with the aim of nondestructive testing of the items made of ferromagnetic materials placed into the Earth's magnetic field. Based on the finite elements method, an algorithm and a computer code for the 3D computations of the magnetic potential distribution in a medium with nonuniform magnetic permeability were developed. The developed methods and software tools were used for the modelling of the leakage field near the fixed-ended heating pipes of the steam boilers. Relationships demonstrating the interrelation between the magnetic induction change and the magnetic leakage field were obtained. A satisfactory coincidence of computational and experimental data concerning the intensity of the magnetic leakage field distribution on the surface of the heating tube was noted.