Image reconstruction of spherical inclusions in ferromagnetic structures using the generalized inverse

Abstract

The generalized inverse method and singular value decomposition were used to reconstruct the magnetic image of small spherical inclusions in ferromagnetic structures. These techniques were used on the magnetic flux leakage generated when the structure is magnetized. The leakage field from the inclusions was simulated by using a simple constantpermeability model. The recovery model used a grid of magnetic dipoles at the region of the inclusions. The ability of the. technique to distinguish between different distributions of inclusions with similar leakage fields is analyzed. The results demonstrates the feasibility of imaging multiple inclusions within the structure.

Research on the influence of composite defects on quantitative pattern in MFL detection of tubing

“…By far, the magnetic dipole method and finite element method are the main research methods of MFL based on modeling. A C Bruno, L Couto Miranda, C Hall Barbosa et al used the magnetic dipole model to solve the forward modeling problem, and then used the generalized inverse matrix theory to minimize the square error between the measured value of the magnetic leakage field and the forward modeling estimate to realize the two-dimensional imaging of simple shape defects [17]. The finite element model calculation theory is established on the basis of Maxwell's equations in electromagnetism, and it is commonly used to analyze the defects with the complex structure, so as to obtain accurate numerical results.…”