Finite element analysis of dynamic linear devices

This paper introduces aspects of finite element linear motion analysis: a transient eddy current program which includes the effects of motion. Field models of electromechanical devices are coupled to motion in a scheme which efficiently models the region between a moving body and a stationary background region; calculates the force on the moving body using the Maxwell stress method (MSM); couples the mechanical and field equations using a 4^th order Runge-Kutta method; and preserves the sparseness and symmetry of the finite element matrix. The capabilities of the program are discussed through example models of a levitation device, a linear permanent magnet stepping motor and a coil moving above a conducting slab.