L. Xin, Z. Zeng, L. Udpa, S. Udpa, Michigan State University, East Lansing, MI

Summary:

Magneto-optic imaging (MOI) is a relatively new sensor application of bubble memory technology to nondestructive evaluation and produces easy-to-interpret, real-time analog images. The availability of a theoretical model that can simulate the MOI system performance is extremely important for the optimization of the magneto-optic (MO) sensor and hardware system. A linear finite element (FE) model utilizing the A-v formulation was initially developed for this purpose. However the inclusion of infinitesimal air gaps between layers render the FE mesh rather wasteful. A more accurate numerical model is strongly, the element-free Galerkin (EFG) method, gives us a efficient framework in the modeling of airframe geometry. A benefit of the EFG method is that it is inherently a high order scheme even with linear polynomial bases, which makes it more accurate than the conventional linear FE method. Another advantage of the EFG lies in its simplicity in the domain discretization because it relies on only a cloud of nodes and does not require an underlying tessellation to describe the domain. Initial results indicate that MO images predicted by the EFG model are much closer to the experimental images than those of the FE model with the same number of unknowns.