Thevenin equivalent fields

The finite element method is a well-established technique in the analysis of electromagnetic fields. A theory of equivalent fields, analogous to equivalent circuits in network theory is developed. It extends diakoptic analysis and permits solution of two (or more) coupled boundary-value problems independently, representing their mutual coupling by appropriate influence constraints and functions. Analytical models are derived, and their impact on numerical methods is explored. This technique is particularly valuable (and can reduce the computing cost of finite element solutions drastically) where detailed results are sought only in a small portion of a large field problem