Nonlinear shape design sensitivity analysis of magnetostatic problems using boundary element method

A design sensitivity analysis is extended to cover the nonlinear magnetostatic problems. The formula is derived using material derivative as boundary integrals of the state and adjoint variables over the deformable boundary. A solution scheme for nonlinear state and adjoint equations using boundary element method is also presented to get accurate sensitivity coefficients. And a normalizing scheme for the pointwise sensitivity coefficients are proposed to avoid zig-zag shapes during optimization.>