Optimization of multilayered nonlinear crystalline alloys for shielding.

An optimization of a multilayered material is presented for the shielding of sinusoidal magnetic fields. The shield consists of alternating layers of aluminum and snonlinear hystereticd steel. The optimization variables are the total shield thickness and the fraction of steel. The optimization goals are to obtain the desired shielding factor, to minimize the shield thickness, and to minimize the eddy currents and hysteresis losses. In the objective function, analytical expressions are used for the shielding factor and the electromagnetic losses. Simulation results of a planar shield show that both the optimal shield thickness and the fraction of steel decrease with the frequency. [ABSTRACT FROM AUTHOR]