Fast nonlinear finite element analysis using Newton-Raphson method implemented by Krylov subspace method with relaxed convergence criterion

Abstract

Purpose – The purpose of this paper is the realization of Fast nonlinear finite element analysis (FEA). Design/methodology/approach – Nonlinear magnetic field analysis is achieved by using Newton-Raphson method implemented by relaxed convergence criterion of Krylov subspace method. Findings – This paper mathematically analyzes the reason why nonlinear convergence can be achieved if the convergence criterion for linearized equation is relaxed. Research limitations/implications – The proposed method is essential to reduce the elapsed time in nonlinear magnetic field analysis of quasi-stationary field. Practical implications – The proposed method is able to be extended to not only static field but also time domain FEA strongly coupled with circuit equation. Social implications – Because the speedup of performance evaluation of electrical machines would be achieved using proposed method, the work efficiency in manufacturing would be accelerated. Originality/value – It can be seen that the nonlinear convergenc...